MDEV-24962: Galera SST innobackupex-move ignores Environment settings

After switching to the new mariabackup interface (instead of
the outdated innobackupex interface, which is supported for
compatibility), we need to explicitly pass a path to the datadir
directory as a parameter, since in the new interface the value
of this option is not automatically set in such a way that it
always matches the SST/IST logic. This commit adds passing this
option as an explicit parameter to mariabackup. This commit also
removed unnecessary options that are not used and not supported
by mariabackup.

Also, numerous flaws in the common wsrep_sst_common script have
been fixed:

 1) There are many bash-specific constructs in the script that
    may not be supported by other interpreters, which can lead
    to the most unexpected errors during SST, because failures
    in the interpretation of bash-specific constructs lead to
    incorrect parsing of arguments;
 2) The parse_cnf() function which is often called by other scripts
    for the "mysqld" or "--mysqld" group, but it does not take into
    account the default group suffix. The suffix is not taken into
    account in wsrep_sst_common, and in all other scripts too,
    which leads to reading values only from the default group,
    which then leads to error due to reading the default values
    instead of the values for a specific group;
 3) Some options such as --innodb-data-home-dir and --datadir
    are not removed from the --mysqld-args list, although they are
    processed inside scripts and further double passing of these
    options may cause problems for mariabackup;
 4) If an argument that the script understands is present in
    the --mysqld-args list twice, then this causes SST to fail,
    instead of reading the most recent value;
 5) The "--host" parameter is technically still supported among
    the arguments to mysqld_common, but in reality scripts do not
    work with it as expected, especially if it has an IPv6 address
    in it;
 6) If the port number is absent in the --address parameter, but
    the port is explicitly passed through the --port parameter,
    then the scripts for mariabackup and xtrabackup-v2 fail;
 7) If a new interface is used (with the --address parameter),
    then automatic port substitution is not performed by default,
    although it is supported for the legacy --host/--port
    interface.
 8) If there are spaces in the parameter values after --mysqld_args,
    then their further transfer does not occur correctly, which
    causes mariabackup to fail during SST if the space splits
    the argument in such a way that it breaks the parsing of the
    parameters;
 9) If most of the parameters that are names and paths for files
    and directories contain spaces, then SST scripts fail in an
    unpredictable way due to incorrect variable substitution;
10) If, among the arguments to mysqld (--mysqld-args), the --log-bin
    option is passed without a parameter, but the --binlog option
    is not passed, then the script cannot substitute the default
    name for binlog and cannot construct it using the --log-basename
    which is against specs;
11) Tail slashes are not removed from directory names, which, upon
    further substitution, leads to the appearance of a double slash
    in the file paths;
12) The explicit --binlog parameter (which is now always transmitted
    from the server side) and the "hidden" --log-bin parameter in the
    list of options after --mysqld-args are perceived as two different
    parameters in two different parts of the scripts, and if they are
    do not match for some reason, it will lead to failures during SST;

11 files changed, 869 insertions, 733 deletions

diff --git a/mysql-test/suite/galera/r/galera_ist_innodb_flush_logs,debug.rdiff b/mysql-test/suite/galera/r/galera_ist_innodb_flush_logs,debug.rdiff
index fa1b67e7ef3..55f1150c930 100644
--- a/mysql-test/suite/galera/r/galera_ist_innodb_flush_logs,debug.rdiff
+++ b/mysql-test/suite/galera/r/galera_ist_innodb_flush_logs,debug.rdiff
@@ -1,11 +1,12 @@
 --- r/galera_ist_innodb_flush_logs.result	2018-09-05 10:34:36.192439933 +0300
 +++ r/galera_ist_innodb_flush_logs.reject	2018-09-17 10:20:06.039150838 +0300
-@@ -86,3 +86,100 @@
+@@ -86,3 +86,111 @@
  DROP TABLE t1;
  COMMIT;
  SET AUTOCOMMIT=ON;
 +Performing State Transfer on a server that has been killed and restarted
 +while a DDL was in progress on it
++connection node_1;
 +CREATE TABLE t1 (f1 CHAR(255)) ENGINE=InnoDB;
 +SET AUTOCOMMIT=OFF;
 +START TRANSACTION;
@@ -14,6 +15,7 @@
 +INSERT INTO t1 VALUES ('node1_committed_before');
 +INSERT INTO t1 VALUES ('node1_committed_before');
 +INSERT INTO t1 VALUES ('node1_committed_before');
++connection node_2;
 +START TRANSACTION;
 +INSERT INTO t1 VALUES ('node2_committed_before');
 +INSERT INTO t1 VALUES ('node2_committed_before');
@@ -22,9 +24,12 @@
 +INSERT INTO t1 VALUES ('node2_committed_before');
 +COMMIT;
 +SET GLOBAL debug_dbug = 'd,sync.alter_opened_table';
++connection node_1;
 +ALTER TABLE t1 ADD COLUMN f2 INTEGER;
++connection node_2;
 +SET wsrep_sync_wait = 0;
 +Killing server ...
++connection node_1;
 +SET AUTOCOMMIT=OFF;
 +START TRANSACTION;
 +INSERT INTO t1 (f1) VALUES ('node1_committed_during');
@@ -39,6 +44,7 @@
 +INSERT INTO t1 (f1) VALUES ('node1_to_be_committed_after');
 +INSERT INTO t1 (f1) VALUES ('node1_to_be_committed_after');
 +INSERT INTO t1 (f1) VALUES ('node1_to_be_committed_after');
++connect node_1a_galera_st_kill_slave_ddl, 127.0.0.1, root, , test, $NODE_MYPORT_1;
 +SET AUTOCOMMIT=OFF;
 +START TRANSACTION;
 +INSERT INTO t1 (f1) VALUES ('node1_to_be_rollbacked_after');
@@ -46,7 +52,9 @@
 +INSERT INTO t1 (f1) VALUES ('node1_to_be_rollbacked_after');
 +INSERT INTO t1 (f1) VALUES ('node1_to_be_rollbacked_after');
 +INSERT INTO t1 (f1) VALUES ('node1_to_be_rollbacked_after');
++connection node_2;
 +Performing --wsrep-recover ...
++connection node_2;
 +Starting server ...
 +Using --wsrep-start-position when starting mysqld ...
 +SET AUTOCOMMIT=OFF;
@@ -57,6 +65,7 @@
 +INSERT INTO t1 (f1) VALUES ('node2_committed_after');
 +INSERT INTO t1 (f1) VALUES ('node2_committed_after');
 +COMMIT;
++connection node_1;
 +INSERT INTO t1 (f1) VALUES ('node1_to_be_committed_after');
 +INSERT INTO t1 (f1) VALUES ('node1_to_be_committed_after');
 +INSERT INTO t1 (f1) VALUES ('node1_to_be_committed_after');
@@ -71,6 +80,7 @@
 +INSERT INTO t1 (f1) VALUES ('node1_committed_after');
 +INSERT INTO t1 (f1) VALUES ('node1_committed_after');
 +COMMIT;
++connection node_1a_galera_st_kill_slave_ddl;
 +INSERT INTO t1 (f1) VALUES ('node1_to_be_rollbacked_after');
 +INSERT INTO t1 (f1) VALUES ('node1_to_be_rollbacked_after');
 +INSERT INTO t1 (f1) VALUES ('node1_to_be_rollbacked_after');
@@ -88,6 +98,7 @@
 +1
 +COMMIT;
 +SET AUTOCOMMIT=ON;
++connection node_1;
 +SELECT COUNT(*) = 2 FROM INFORMATION_SCHEMA.COLUMNS WHERE TABLE_NAME = 't1';
 +COUNT(*) = 2
 +1
diff --git a/mysql-test/suite/galera/r/galera_ist_xtrabackup-v2.result b/mysql-test/suite/galera/r/galera_ist_xtrabackup-v2.result
index 8a7c02ab1b6..80a28d349ba 100644
--- a/mysql-test/suite/galera/r/galera_ist_xtrabackup-v2.result
+++ b/mysql-test/suite/galera/r/galera_ist_xtrabackup-v2.result
@@ -21,7 +21,7 @@ INSERT INTO t1 VALUES ('node2_committed_before');
 INSERT INTO t1 VALUES ('node2_committed_before');
 COMMIT;
 Unloading wsrep provider ...
-SET GLOBAL wsrep_provider = 'none';
+SET GLOBAL wsrep_cluster_address = '';
 connection node_1;
 SET AUTOCOMMIT=OFF;
 START TRANSACTION;
diff --git a/mysql-test/suite/galera/t/galera_ist_innodb_flush_logs.cnf b/mysql-test/suite/galera/t/galera_ist_innodb_flush_logs.cnf
index b91c897e66e..a93c291b47c 100644
--- a/mysql-test/suite/galera/t/galera_ist_innodb_flush_logs.cnf
+++ b/mysql-test/suite/galera/t/galera_ist_innodb_flush_logs.cnf
@@ -1,7 +1,7 @@
 !include ../galera_2nodes.cnf
 
 [mysqld]
-wsrep_sst_method=xtrabackup-v2
+wsrep_sst_method=mariabackup
 wsrep_sst_auth=root:
 innodb_safe_truncate=OFF
 
diff --git a/mysql-test/suite/galera/t/galera_ist_innodb_flush_logs.test b/mysql-test/suite/galera/t/galera_ist_innodb_flush_logs.test
index 839383ebfc1..fd362a26840 100644
--- a/mysql-test/suite/galera/t/galera_ist_innodb_flush_logs.test
+++ b/mysql-test/suite/galera/t/galera_ist_innodb_flush_logs.test
@@ -7,7 +7,7 @@
 --source include/big_test.inc
 --source include/galera_cluster.inc
 --source include/have_innodb.inc
---source include/have_xtrabackup.inc
+--source include/have_mariabackup.inc
 
 --source suite/galera/include/galera_st_kill_slave.inc
 --source suite/galera/include/galera_st_kill_slave_ddl.inc
diff --git a/mysql-test/suite/galera/t/galera_sst_xtrabackup-v2_encrypt_with_key.cnf b/mysql-test/suite/galera/t/galera_sst_xtrabackup-v2_encrypt_with_key.cnf
index 792b0d15ac4..7a98fd2aa58 100644
--- a/mysql-test/suite/galera/t/galera_sst_xtrabackup-v2_encrypt_with_key.cnf
+++ b/mysql-test/suite/galera/t/galera_sst_xtrabackup-v2_encrypt_with_key.cnf
@@ -7,7 +7,7 @@ wsrep_debug=ON
 innodb_safe_truncate=OFF
 
 [SST]
-tkey=@ENV.MYSQL_TEST_DIR/std_data/galera-key.pem
-tcert=@ENV.MYSQL_TEST_DIR/std_data/galera-cert.pem
+tkey=@ENV.MYSQL_TEST_DIR/std_data/cakey.pem
+tcert=@ENV.MYSQL_TEST_DIR/std_data/cacert.pem
 encrypt=3
 transferfmt=@ENV.MTR_GALERA_TFMT
diff --git a/scripts/wsrep_sst_common.sh b/scripts/wsrep_sst_common.sh
index 443cb26ab64..9e9e3aa6075 100644
--- a/scripts/wsrep_sst_common.sh
+++ b/scripts/wsrep_sst_common.sh
@@ -21,24 +21,31 @@ set -u
 WSREP_SST_OPT_BYPASS=0
 WSREP_SST_OPT_BINLOG=""
 WSREP_SST_OPT_BINLOG_INDEX=""
+WSREP_SST_OPT_LOG_BASENAME=""
 WSREP_SST_OPT_DATA=""
-WSREP_SST_OPT_AUTH=${WSREP_SST_OPT_AUTH:-}
-WSREP_SST_OPT_USER=${WSREP_SST_OPT_USER:-}
-WSREP_SST_OPT_PSWD=${WSREP_SST_OPT_PSWD:-}
+WSREP_SST_OPT_AUTH="${WSREP_SST_OPT_AUTH:-}"
+WSREP_SST_OPT_USER="${WSREP_SST_OPT_USER:-}"
+WSREP_SST_OPT_PSWD="${WSREP_SST_OPT_PSWD:-}"
 WSREP_SST_OPT_DEFAULT=""
 WSREP_SST_OPT_EXTRA_DEFAULT=""
 WSREP_SST_OPT_SUFFIX_DEFAULT=""
 WSREP_SST_OPT_SUFFIX_VALUE=""
 WSREP_SST_OPT_MYSQLD=""
-INNODB_DATA_HOME_DIR_ARG=""
-INNODB_LOG_GROUP_HOME_ARG=""
-INNODB_UNDO_DIR_ARG=""
-LOG_BIN_ARG=""
+WSREP_SST_OPT_PORT=""
+WSREP_SST_OPT_ADDR=""
+WSREP_SST_OPT_ADDR_PORT=""
+WSREP_SST_OPT_HOST=""
+WSREP_SST_OPT_HOST_UNESCAPED=""
+WSREP_SST_OPT_HOST_ESCAPED=""
+INNODB_DATA_HOME_DIR="${INNODB_DATA_HOME_DIR:-}"
+INNODB_LOG_GROUP_HOME="${INNODB_LOG_GROUP_HOME:-}"
+INNODB_UNDO_DIR="${INNODB_UNDO_DIR:-}"
+INNOEXTRA=""
 
 while [ $# -gt 0 ]; do
 case "$1" in
     '--address')
-        readonly WSREP_SST_OPT_ADDR="$2"
+        WSREP_SST_OPT_ADDR="$2"
         #
         # Break address string into host:port/path parts
         #
@@ -46,60 +53,61 @@ case "$1" in
         \[*)
             # IPv6
             # Remove the starting and ending square brackets, if present:
-            addr_no_bracket=${WSREP_SST_OPT_ADDR#\[}
-            readonly WSREP_SST_OPT_HOST_UNESCAPED=${addr_no_bracket%%\]*}
-            # Square brackets are needed in most cases:
-            readonly WSREP_SST_OPT_HOST="[${WSREP_SST_OPT_HOST_UNESCAPED}]"
+            addr_no_bracket="${WSREP_SST_OPT_ADDR#\[}"
             # Some utilities and subsequent code require an address
             # without square brackets:
+            readonly WSREP_SST_OPT_HOST_UNESCAPED="${addr_no_bracket%%\]*}"
+            # Square brackets are needed in most cases:
+            readonly WSREP_SST_OPT_HOST="[${WSREP_SST_OPT_HOST_UNESCAPED}]"
             readonly WSREP_SST_OPT_HOST_ESCAPED="\\[${WSREP_SST_OPT_HOST_UNESCAPED}\\]"
+            # Mark this address as IPv6:
             readonly WSREP_SST_OPT_HOST_IPv6=1
             ;;
         *)
-            readonly WSREP_SST_OPT_HOST=${WSREP_SST_OPT_ADDR%%[:/]*}
-            readonly WSREP_SST_OPT_HOST_UNESCAPED=$WSREP_SST_OPT_HOST
-            readonly WSREP_SST_OPT_HOST_ESCAPED=$WSREP_SST_OPT_HOST
+            readonly WSREP_SST_OPT_HOST="${WSREP_SST_OPT_ADDR%%[:/]*}"
+            readonly WSREP_SST_OPT_HOST_UNESCAPED="$WSREP_SST_OPT_HOST"
+            readonly WSREP_SST_OPT_HOST_ESCAPED="$WSREP_SST_OPT_HOST"
             readonly WSREP_SST_OPT_HOST_IPv6=0
             ;;
         esac
         # Let's remove the leading part that contains the host address:
-        remain=${WSREP_SST_OPT_ADDR#${WSREP_SST_OPT_HOST_ESCAPED}}
+        remain="${WSREP_SST_OPT_ADDR#$WSREP_SST_OPT_HOST_ESCAPED}"
         # Let's remove the ":" character that separates the port number
         # from the hostname:
-        remain=${remain#:}
+        remain="${remain#:}"
         # Extract the port number from the address - all characters
         # up to "/" (if present):
-        readonly WSREP_SST_OPT_ADDR_PORT=${remain%%/*}
+        WSREP_SST_OPT_ADDR_PORT="${remain%%/*}"
         # If the "/" character is present, then the path is not empty:
         if [ "${remain#*/}" != "${remain}" ]; then
             # This operation removes everything up to the "/" character,
             # effectively removing the port number from the string:
-            readonly WSREP_SST_OPT_PATH=${remain#*/}
+            readonly WSREP_SST_OPT_PATH="${remain#*/}"
         else
             readonly WSREP_SST_OPT_PATH=""
         fi
         # The rest of the string is the same as the path (for now):
-        remain=${WSREP_SST_OPT_PATH}
+        remain="${WSREP_SST_OPT_PATH}"
         # If there is one more "/" in the string, then everything before
         # it will be the module name, otherwise the module name is empty:
         if [ "${remain%%/*}" != "${remain}" ]; then
             # This operation removes the tail after the very first
             # occurrence of the "/" character (inclusively):
-            readonly WSREP_SST_OPT_MODULE=${remain%%/*}
+            readonly WSREP_SST_OPT_MODULE="${remain%%/*}"
         else
             readonly WSREP_SST_OPT_MODULE=""
         fi
         # Remove the module name part from the string, which ends with "/":
-        remain=${WSREP_SST_OPT_PATH#*/}
+        remain="${WSREP_SST_OPT_PATH#*/}"
         # If the rest of the string does not match the original, then there
         # was something else besides the module name:
         if [ "$remain" != "${WSREP_SST_OPT_PATH}" ]; then
             # Extract the part that matches the LSN by removing all
             # characters starting from the very first "/":
-            readonly WSREP_SST_OPT_LSN=${remain%%/*}
+            readonly WSREP_SST_OPT_LSN="${remain%%/*}"
             # Exctract everything after the first occurrence of
             # the "/" character in the string:
-            remain=${remain#*/}
+            remain="${remain#*/}"
             # If the remainder does not match the original string,
             # then there is something else (the version number in
             # our case):
@@ -107,7 +115,7 @@ case "$1" in
                 # Let's extract the version number by removing the tail
                 # after the very first occurence of the "/" character
                 # (inclusively):
-                readonly WSREP_SST_OPT_SST_VER=${remain%%/*}
+                readonly WSREP_SST_OPT_SST_VER="${remain%%/*}"
             else
                 readonly WSREP_SST_OPT_SST_VER=""
             fi
@@ -121,23 +129,23 @@ case "$1" in
         WSREP_SST_OPT_BYPASS=1
         ;;
     '--datadir')
-        readonly WSREP_SST_OPT_DATA="$2"
+        # Let's remove the trailing slash:
+        readonly WSREP_SST_OPT_DATA="${2%/}"
         shift
         ;;
     '--innodb-data-home-dir')
-        readonly INNODB_DATA_HOME_DIR_ARG="$2"
+        # Let's remove the trailing slash:
+        readonly INNODB_DATA_HOME_DIR="${2%/}"
         shift
         ;;
     '--innodb-log-group-home-dir')
-        readonly INNODB_LOG_GROUP_HOME_ARG="$2"
+        # Let's remove the trailing slash:
+        readonly INNODB_LOG_GROUP_HOME="${2%/}"
         shift
         ;;
     '--innodb-undo-directory')
-        readonly INNODB_UNDO_DIR_ARG="$2"
-        shift
-        ;;
-    '--log-bin')
-        readonly LOG_BIN_ARG="$2"
+        # Let's remove the trailing slash:
+        readonly INNODB_UNDO_DIR="${2%/}"
         shift
         ;;
     '--defaults-file')
@@ -154,7 +162,28 @@ case "$1" in
         shift
         ;;
     '--host')
-        readonly WSREP_SST_OPT_HOST="$2"
+        case "$2" in
+        \[*)
+            # IPv6
+            # Remove the starting and ending square brackets, if present:
+            addr_no_bracket="${2#\[}"
+            # Some utilities and subsequent code require an address
+            # without square brackets:
+            readonly WSREP_SST_OPT_HOST_UNESCAPED="${addr_no_bracket%%\]*}"
+            # Square brackets are needed in most cases:
+            readonly WSREP_SST_OPT_HOST="[${WSREP_SST_OPT_HOST_UNESCAPED}]"
+            readonly WSREP_SST_OPT_HOST_ESCAPED="\\[${WSREP_SST_OPT_HOST_UNESCAPED}\\]"
+            # Mark this address as IPv6:
+            readonly WSREP_SST_OPT_HOST_IPv6=1
+            ;;
+        *)
+            readonly WSREP_SST_OPT_HOST="$2"
+            readonly WSREP_SST_OPT_HOST_UNESCAPED="$2"
+            readonly WSREP_SST_OPT_HOST_ESCAPED="$2"
+            readonly WSREP_SST_OPT_HOST_IPv6=0
+            ;;
+        esac
+        WSREP_SST_OPT_ADDR="$WSREP_SST_OPT_HOST"
         shift
         ;;
     '--local-port')
@@ -189,14 +218,18 @@ case "$1" in
         readonly WSREP_SST_OPT_GTID="$2"
         shift
         ;;
-    '--binlog')
-        WSREP_SST_OPT_BINLOG="$2"
+    '--binlog'|'--log-bin')
+        readonly WSREP_SST_OPT_BINLOG="$2"
+        shift
+        ;;
+    '--binlog-index'|'--log-bin-index')
+        readonly WSREP_SST_OPT_BINLOG_INDEX="$2"
+        shift
+        ;;
+    '--log-basename')
+        readonly WSREP_SST_OPT_LOG_BASENAME="$2"
         shift
         ;;
-    '--binlog-index')
-	WSREP_SST_OPT_BINLOG_INDEX="$2"
-	shift
-	;;
     '--gtid-domain-id')
         readonly WSREP_SST_OPT_GTID_DOMAIN_ID="$2"
         shift
@@ -205,42 +238,76 @@ case "$1" in
         original_cmd=""
         shift
         while [ $# -gt 0 ]; do
-           option=${1%%=*}
-           if [[ "$option" != "--defaults-file" && \
-                 "$option" != "--defaults-extra-file" && \
-                 "$option" != "--defaults-group-suffix" && \
-                 "$option" != "--port" && \
-                 "$option" != "--socket" ]]; then
-              value=${1#*=}
-              if [ "$value" == "$1" ]; then
+           option="${1%%=*}"
+           if [ "$option" != '--defaults-file' -a \
+                "$option" != '--defaults-extra-file' -a \
+                "$option" != '--defaults-group-suffix' -a \
+                "$option" != '--port' -a \
+                "$option" != '--socket' ]; then
+              value="${1#*=}"
+              if [ "$value" = "$1" ]; then
                  value=""
               fi
+              # Let's fill in the variables containing important paths
+              # that might not have been passed through explicit parameters
+              # (+ removing the trailing slash in these paths). Many of these
+              # options are processed internally within scripts or passed
+              # explicitly to other programs, so we need to remove them
+              # from mysqld's argument list:
+              skip_mysqld_arg=0
               case "$option" in
                   '--innodb-data-home-dir')
-                      if [ -z "$INNODB_DATA_HOME_DIR_ARG" ]; then
-                          readonly INNODB_DATA_HOME_DIR_ARG="$value"
+                      if [ -z "$INNODB_DATA_HOME_DIR" ]; then
+                          MYSQLD_OPT_INNODB_DATA_HOME_DIR="${value%/}"
                       fi
+                      skip_mysqld_arg=1
                       ;;
                   '--innodb-log-group-home-dir')
-                      if [ -z "$INNODB_LOG_GROUP_HOME_ARG" ]; then
-                          readonly INNODB_LOG_GROUP_HOME_ARG="$value"
+                      if [ -z "$INNODB_LOG_GROUP_HOME" ]; then
+                          MYSQLD_OPT_INNODB_LOG_GROUP_HOME="${value%/}"
                       fi
+                      skip_mysqld_arg=1
                       ;;
                   '--innodb-undo-directory')
-                      if [ -z "$INNODB_UNDO_DIR_ARG" ]; then
-                          readonly INNODB_UNDO_DIR_ARG="$value"
+                      if [ -z "$INNODB_UNDO_DIR" ]; then
+                          MYSQLD_OPT_INNODB_UNDO_DIR="${value%/}"
                       fi
+                      skip_mysqld_arg=1
                       ;;
                   '--log-bin')
-                      if [ -z "$LOG_BIN_ARG" ]; then
-                          readonly LOG_BIN_ARG="$value"
+                      if [ -z "$WSREP_SST_OPT_BINLOG" ]; then
+                          MYSQLD_OPT_LOG_BIN="$value"
+                      fi
+                      # If this option has no parameter, then it does not
+                      # need to be removed from the mysqld arguments list:
+                      if [ -n "$value" ]; then
+                          skip_mysqld_arg=1
+                      fi
+                      ;;
+                  '--log-bin-index')
+                      if [ -z "$WSREP_SST_OPT_BINLOG_INDEX" ]; then
+                          MYSQLD_OPT_LOG_BIN_INDEX="$value"
+                      fi
+                      skip_mysqld_arg=1
+                      ;;
+                  '--log-basename')
+                      if [ -z "$WSREP_SST_OPT_LOG_BASENAME" ]; then
+                          MYSQLD_OPT_LOG_BASENAME="$value"
                       fi
                       ;;
+                  '--datadir'|'-h')
+                      if [ -z "$WSREP_SST_OPT_DATA" ]; then
+                          MYSQLD_OPT_DATADIR="${value%/}"
+                      fi
+                      skip_mysqld_arg=1
+                      ;;
               esac
-              if [ -z "$original_cmd" ]; then
-                  original_cmd="$1"
-              else
-                  original_cmd="$original_cmd $1"
+              if [ $skip_mysqld_arg -eq 0 ]; then
+                  if [ -z "$original_cmd" ]; then
+                      original_cmd="'$1'"
+                  else
+                      original_cmd="$original_cmd '$1'"
+                  fi
               fi
            fi
            shift
@@ -256,20 +323,157 @@ esac
 shift
 done
 readonly WSREP_SST_OPT_BYPASS
-readonly WSREP_SST_OPT_BINLOG
-readonly WSREP_SST_OPT_BINLOG_INDEX
-
-if [ -n "${WSREP_SST_OPT_ADDR_PORT:-}" ]; then
-  if [ -n "${WSREP_SST_OPT_PORT:-}" ]; then
-    if [ "$WSREP_SST_OPT_PORT" != "$WSREP_SST_OPT_ADDR_PORT" ]; then
-      echo "WSREP_SST: [ERROR] port in --port=$WSREP_SST_OPT_PORT differs from port in --address=$WSREP_SST_OPT_ADDR" >&2
-      exit 2
+
+# The same argument can be present on the command line several
+# times, in this case we must take its last value:
+if [ -n "${MYSQLD_OPT_INNODB_DATA_HOME_DIR:-}" -a \
+     -z "$INNODB_DATA_HOME_DIR" ]; then
+    readonly INNODB_DATA_HOME_DIR="$MYSQLD_OPT_INNODB_DATA_HOME_DIR"
+fi
+if [ -n "${MYSQLD_OPT_INNODB_LOG_GROUP_HOME:-}" -a \
+     -z "$INNODB_LOG_GROUP_HOME" ]; then
+    readonly INNODB_LOG_GROUP_HOME="$MYSQLD_OPT_INNODB_LOG_GROUP_HOME"
+fi
+if [ -n "${MYSQLD_OPT_INNODB_UNDO_DIR:-}" -a \
+     -z "$INNODB_UNDO_DIR" ]; then
+    readonly INNODB_UNDO_DIR="$MYSQLD_OPT_INNODB_UNDO_DIR"
+fi
+if [ -n "${MYSQLD_OPT_LOG_BIN:-}" -a \
+     -z "$WSREP_SST_OPT_BINLOG" ]; then
+    readonly WSREP_SST_OPT_BINLOG="$MYSQLD_OPT_LOG_BIN"
+fi
+if [ -n "${MYSQLD_OPT_LOG_BIN_INDEX:-}" -a \
+     -z "$WSREP_SST_OPT_BINLOG_INDEX" ]; then
+    readonly WSREP_SST_OPT_BINLOG_INDEX="$MYSQLD_OPT_LOG_BIN_INDEX"
+fi
+if [ -n "${MYSQLD_OPT_DATADIR:-}" -a \
+     -z "$WSREP_SST_OPT_DATA" ]; then
+    readonly WSREP_SST_OPT_DATA="$MYSQLD_OPT_DATADIR"
+fi
+if [ -n "${MYSQLD_OPT_LOG_BASENAME:-}" -a \
+     -z "$WSREP_SST_OPT_LOG_BASENAME" ]; then
+    readonly WSREP_SST_OPT_LOG_BASENAME="$MYSQLD_OPT_DATADIR"
+fi
+
+# Reconstructing the command line arguments that control the innodb
+# and binlog options:
+if [ -n "$INNODB_DATA_HOME_DIR" ]; then
+    INNOEXTRA="$INNOEXTRA --innodb-data-home-dir='$INNODB_DATA_HOME_DIR'"
+fi
+if [ -n "$INNODB_LOG_GROUP_HOME" ]; then
+    INNOEXTRA="$INNOEXTRA --innodb-log-group-home-dir='$INNODB_LOG_GROUP_HOME'"
+fi
+if [ -n "$INNODB_UNDO_DIR" ]; then
+    INNOEXTRA="$INNOEXTRA --innodb-undo-directory='$INNODB_UNDO_DIR'"
+fi
+if [ -n "$WSREP_SST_OPT_BINLOG" ]; then
+    INNOEXTRA="$INNOEXTRA --log-bin='$WSREP_SST_OPT_BINLOG'"
+    if [ -n "$WSREP_SST_OPT_BINLOG_INDEX" ]; then
+        INNOEXTRA="$INNOEXTRA --log-bin-index='$WSREP_SST_OPT_BINLOG_INDEX'"
+    fi
+fi
+
+get_binlog() {
+    # if no command line argument and WSREP_SST_OPT_BINLOG is not set,
+    # try to get it from my.cnf:
+    if [ -z "$WSREP_SST_OPT_BINLOG" ]; then
+        WSREP_SST_OPT_BINLOG=$(parse_cnf '--mysqld' 'log-bin')
+    fi
+    # if no command line argument and WSREP_SST_OPT_BINLOG_INDEX is not set,
+    # try to get it from my.cnf:
+    if [ -z "$WSREP_SST_OPT_BINLOG_INDEX" ]; then
+        WSREP_SST_OPT_BINLOG_INDEX=$(parse_cnf '--mysqld' 'log-bin-index')
+    fi
+    # if no command line argument and WSREP_SST_OPT_LOG_BASENAME is not set,
+    # try to get it from my.cnf:
+    if [ -z "$WSREP_SST_OPT_LOG_BASENAME" ]; then
+        WSREP_SST_OPT_LOG_BASENAME=$(parse_cnf '--mysqld' 'log-basename')
+    fi
+    if [ -z "$WSREP_SST_OPT_BINLOG" ]; then
+        if [ -n "${MYSQLD_OPT_LOG_BIN+x}" ]; then
+            if [ -n "$WSREP_SST_OPT_LOG_BASENAME" ]; then
+                # If the WSREP_SST_OPT_BINLOG variable is not set, but
+                # --log-basename is present among the arguments to mysqld,
+                # then set WSREP_SST_OPT_BINLOG equal to the base name with
+                # the "-bin" suffix:
+                readonly WSREP_SST_OPT_BINLOG="$WSREP_SST_OPT_LOG_BASENAME-bin"
+            else
+                # If the --log-bin option is present without a value, then
+                # we take the default name:
+                readonly WSREP_SST_OPT_BINLOG='mysqld-bin'
+            fi
+        fi
+    fi
+    if [ -n "$WSREP_SST_OPT_BINLOG" ]; then
+        if [ -z "$WSREP_SST_OPT_BINLOG_INDEX" ]; then
+            if [ -n "$WSREP_SST_OPT_LOG_BASENAME" ]; then
+                # If the WSREP_SST_OPT_BINLOG variable is not set, but
+                # --log-basename is present among the arguments to mysqld,
+                # then set WSREP_SST_OPT_BINLOG equal to the base name with
+                # the "-bin" suffix:
+                readonly WSREP_SST_OPT_BINLOG_INDEX="$WSREP_SST_OPT_LOG_BASENAME-bin.index"
+            else
+                # If the --log-bin option is present without a value, then
+                # we take the default name:
+                readonly WSREP_SST_OPT_BINLOG_INDEX='mysqld-bin.index'
+            fi
+        fi
+    fi
+}
+
+# Setting WSREP_SST_OPT_BINLOG by using other arguments:
+if [ -z "$WSREP_SST_OPT_BINLOG" ]; then
+   if [ -n "$WSREP_SST_OPT_LOG_BASENAME" ]; then
+      # If the WSREP_SST_OPT_BINLOG variable is not set, but
+      # --log-basename is present among the arguments to mysqld,
+      # then set WSREP_SST_OPT_BINLOG equal to the base name with
+      # the "-bin" suffix:
+      readonly WSREP_SST_OPT_BINLOG="$WSREP_SST_OPT_LOG_BASENAME-bin"
+   elif [ -n "${MYSQLD_OPT_LOG_BIN+x}" ]; then
+      # If the --log-bin option is present without a value, then
+      # we take the default name:
+      readonly WSREP_SST_OPT_BINLOG='mysql-bin'
+   fi
+fi
+
+# Let's transfer the port from the address to the WSREP_SST_OPT_PORT
+# variable, or vice versa, substitute the missing port value into the
+# address:
+if [ -n "$WSREP_SST_OPT_ADDR_PORT" ]; then
+    if [ -n "$WSREP_SST_OPT_PORT" ]; then
+        if [ "$WSREP_SST_OPT_PORT" != "$WSREP_SST_OPT_ADDR_PORT" ]; then
+            echo "WSREP_SST: [ERROR] port in --port=$WSREP_SST_OPT_PORT differs from port in --address=$WSREP_SST_OPT_ADDR" >&2
+            exit 2
+        fi
+    else
+        # If the address contains a port number, assign it to
+        # the corresponding variable:
+        readonly WSREP_SST_OPT_PORT="$WSREP_SST_OPT_ADDR_PORT"
+    fi
+elif [ -n "$WSREP_SST_OPT_ADDR" ]; then
+    # If the port is missing, take the default port:
+    if [ -z "$WSREP_SST_OPT_PORT" ]; then
+        readonly WSREP_SST_OPT_PORT=4444
+    fi
+    WSREP_SST_OPT_ADDR_PORT="$WSREP_SST_OPT_PORT"
+    # Let's remove the leading part that contains the host address:
+    remain="${WSREP_SST_OPT_ADDR#$WSREP_SST_OPT_HOST_ESCAPED}"
+    # Let's remove the ":" character that separates the port number
+    # from the hostname:
+    remain="${remain#:}"
+    # Let's remove all characters upto first "/" character that
+    # separates the hostname with port number from the path:
+    remain="${remain#/}"
+    # Let's construct a new value for the address with the port:
+    WSREP_SST_OPT_ADDR="$WSREP_SST_OPT_HOST:$WSREP_SST_OPT_PORT"
+    if [ -n "$remain" ]; then
+        WSREP_SST_OPT_ADDR="$WSREP_SST_OPT_ADDR/$remain"
     fi
-  else
-    readonly WSREP_SST_OPT_PORT="$WSREP_SST_OPT_ADDR_PORT"
-  fi
 fi
 
+readonly WSREP_SST_OPT_ADDR
+readonly WSREP_SST_OPT_ADDR_PORT
+
 # try to use my_print_defaults, mysql and mysqldump that come with the sources
 # (for MTR suite)
 SCRIPTS_DIR="$(cd $(dirname "$0"); pwd -P)"
@@ -279,13 +483,13 @@ CLIENT_DIR="$SCRIPTS_DIR/../client"
 if [ -x "$CLIENT_DIR/mysql" ]; then
     MYSQL_CLIENT="$CLIENT_DIR/mysql"
 else
-    MYSQL_CLIENT=$(which mysql)
+    MYSQL_CLIENT="$(command -v mysql)"
 fi
 
 if [ -x "$CLIENT_DIR/mysqldump" ]; then
     MYSQLDUMP="$CLIENT_DIR/mysqldump"
 else
-    MYSQLDUMP=$(which mysqldump)
+    MYSQLDUMP="$(command -v mysqldump)"
 fi
 
 if [ -x "$SCRIPTS_DIR/my_print_defaults" ]; then
@@ -293,7 +497,7 @@ if [ -x "$SCRIPTS_DIR/my_print_defaults" ]; then
 elif [ -x "$EXTRA_DIR/my_print_defaults" ]; then
     MY_PRINT_DEFAULTS="$EXTRA_DIR/my_print_defaults"
 else
-    MY_PRINT_DEFAULTS=$(which my_print_defaults)
+    MY_PRINT_DEFAULTS="$(command -v my_print_defaults)"
 fi
 
 wsrep_defaults="$WSREP_SST_OPT_DEFAULT"
@@ -307,16 +511,50 @@ fi
 readonly WSREP_SST_OPT_CONF="$wsrep_defaults$WSREP_SST_OPT_SUFFIX_DEFAULT"
 readonly MY_PRINT_DEFAULTS="$MY_PRINT_DEFAULTS $WSREP_SST_OPT_CONF"
 
+#
+# user can specify mariabackup specific settings that will be used during sst
+# process like encryption, etc.....
+# parse such configuration option. (group for xb settings is [sst] in my.cnf
+#
+# 1st param: group (config file section like sst) or my_print_defaults argument (like --mysqld)
+# 2nd param: var : name of the variable in the section, e.g. server-id
+# 3rd param: - : default value for the param
+parse_cnf()
+{
+    local group="$1"
+    local var="$2"
+    local reval=""
+
+    # normalize the variable names specified in cnf file (user can use _ or - for example log-bin or log_bin)
+    # then search for needed variable
+    # finally get the variable value (if variables has been specified multiple time use the last value only)
+
+    if [ "$group" = '--mysqld' -o \
+         "$group" = 'mysqld' ]; then
+       if [ -n "$WSREP_SST_OPT_SUFFIX_VALUE" ]; then
+           reval=$($MY_PRINT_DEFAULTS "mysqld$WSREP_SST_OPT_SUFFIX_VALUE" | awk 'BEGIN {OFS=FS="="} {gsub(/_/,"-",$1); if ($1=="--'"$var"'") lastval=substr($0,length($1)+2)} END {print lastval}')
+       fi
+    fi
+
+    if [ -z "$reval" ]; then
+        reval=$($MY_PRINT_DEFAULTS "$group" | awk 'BEGIN {OFS=FS="="} {gsub(/_/,"-",$1); if ($1=="--'"$var"'") lastval=substr($0,length($1)+2)} END {print lastval}')
+    fi
+
+    # use default if we haven't found a value
+    if [ -z "$reval" ]; then
+        [ -n "${3:-}" ] && reval="$3"
+    fi
+    echo $reval
+}
+
 wsrep_auth_not_set()
 {
-    [ -z "$WSREP_SST_OPT_AUTH" -o "$WSREP_SST_OPT_AUTH" = "(null)" ]
+    [ -z "$WSREP_SST_OPT_AUTH" -o "$WSREP_SST_OPT_AUTH" = '(null)' ]
 }
 
 # State Snapshot Transfer authentication password was displayed in the ps output. Bug fixed #1200727.
-if $MY_PRINT_DEFAULTS sst | grep -q "wsrep_sst_auth"; then
-    if wsrep_auth_not_set; then
-            WSREP_SST_OPT_AUTH=$($MY_PRINT_DEFAULTS sst | grep -- "--wsrep_sst_auth" | cut -d= -f2)
-    fi
+if wsrep_auth_not_set; then
+    WSREP_SST_OPT_AUTH=$(parse_cnf 'sst' 'wsrep-sst-auth')
 fi
 readonly WSREP_SST_OPT_AUTH
 
@@ -329,7 +567,7 @@ fi
 readonly WSREP_SST_OPT_USER
 readonly WSREP_SST_OPT_PSWD
 
-if [ -n "${WSREP_SST_OPT_DATA:-}" ]
+if [ -n "$WSREP_SST_OPT_DATA" ]
 then
     SST_PROGRESS_FILE="$WSREP_SST_OPT_DATA/sst_in_progress"
 else
@@ -361,15 +599,14 @@ wsrep_log_info()
 
 wsrep_cleanup_progress_file()
 {
-    [ -n "${SST_PROGRESS_FILE:-}" ] && rm -f "$SST_PROGRESS_FILE" 2>/dev/null || true
+    [ -n "$SST_PROGRESS_FILE" ] && rm -f "$SST_PROGRESS_FILE" 2>/dev/null || true
 }
 
 wsrep_check_program()
 {
-    local prog=$1
+    local prog="$1"
 
-    if ! which $prog >/dev/null
-    then
+    if ! [ -x $(command -v "$prog") ]; then
         echo "'$prog' not found in PATH"
         return 2 # no such file or directory
     fi
@@ -388,29 +625,11 @@ wsrep_check_programs()
     return $ret
 }
 
-#
-# user can specify mariabackup specific settings that will be used during sst
-# process like encryption, etc.....
-# parse such configuration option. (group for xb settings is [sst] in my.cnf
-#
-# 1st param: group (config file section like sst) or my_print_defaults argument (like --mysqld)
-# 2nd param: var : name of the variable in the section, e.g. server-id
-# 3rd param: - : default value for the param
-parse_cnf()
+wsrep_check_datadir()
 {
-    local group=$1
-    local var=$2
-    local reval=""
-
-    # normalize the variable names specified in cnf file (user can use _ or - for example log-bin or log_bin)
-    # then search for needed variable
-    # finally get the variable value (if variables has been specified multiple time use the last value only)
-
-    reval=$($MY_PRINT_DEFAULTS "${group}" | awk -v var="${var}" 'BEGIN { OFS=FS="=" } { gsub(/_/,"-",$1); if ( $1=="--"var) lastval=substr($0,length($1)+2) } END { print lastval}')
-
-    # use default if we haven't found a value
-    if [ -z "$reval" ]; then
-        [ -n "$3" ] && reval=$3
+    if [ -z "$WSREP_SST_OPT_DATA" ]
+    then
+        wsrep_log_error "The '--datadir' parameter must be passed to the SST script"
+        exit 2
     fi
-    echo $reval
 }
diff --git a/scripts/wsrep_sst_mariabackup.sh b/scripts/wsrep_sst_mariabackup.sh
index 0499b6c0678..6d837c01d4d 100644
--- a/scripts/wsrep_sst_mariabackup.sh
+++ b/scripts/wsrep_sst_mariabackup.sh
@@ -21,6 +21,7 @@
 # Make sure to read that before proceeding!
 
 . $(dirname $0)/wsrep_sst_common
+wsrep_check_datadir
 
 OS=$(uname)
 ealgo=""
@@ -56,8 +57,6 @@ sfmt="tar"
 strmcmd=""
 tfmt=""
 tcmd=""
-rebuild=0
-rebuildcmd=""
 payload=0
 pvformat="-F '%N => Rate:%r Avg:%a Elapsed:%t %e Bytes: %b %p' "
 pvopts="-f -i 10 -N $WSREP_SST_OPT_ROLE "
@@ -84,9 +83,8 @@ pcmd="pv $pvopts"
 declare -a RC
 
 set +e
-INNOBACKUPEX_BIN=$(which mariabackup)
-if test -z $INNOBACKUPEX_BIN
-then
+MARIABACKUP_BIN="$(command -v mariabackup)"
+if [ -z "$MARIABACKUP_BIN" ]; then
   wsrep_log_error 'mariabackup binary not found in $PATH'
   exit 42
 fi
@@ -97,16 +95,16 @@ XBCRYPT_BIN=xbcrypt # Not available in MariaBackup
 DATA="${WSREP_SST_OPT_DATA}"
 INFO_FILE="xtrabackup_galera_info"
 IST_FILE="xtrabackup_ist"
-MAGIC_FILE="${DATA}/${INFO_FILE}"
-INNOAPPLYLOG="${DATA}/mariabackup.prepare.log"
-INNOMOVELOG="${DATA}/mariabackup.move.log"
-INNOBACKUPLOG="${DATA}/mariabackup.backup.log"
+MAGIC_FILE="$DATA/$INFO_FILE"
+INNOAPPLYLOG="$DATA/mariabackup.prepare.log"
+INNOMOVELOG="$DATA/mariabackup.move.log"
+INNOBACKUPLOG="$DATA/mariabackup.backup.log"
 
 # Setting the path for ss and ip
 export PATH="/usr/sbin:/sbin:$PATH"
 
 timeit(){
-    local stage=$1
+    local stage="$1"
     shift
     local cmd="$@"
     local x1 x2 took extcode
@@ -131,18 +129,18 @@ timeit(){
 get_keys()
 {
     # $encrypt -eq 1 is for internal purposes only
-    if [[ $encrypt -ge 2 || $encrypt -eq -1 ]];then
+    if [ $encrypt -ge 2 -o $encrypt -eq -1 ]; then
         return
     fi
 
-    if [[ $encrypt -eq 0 ]];then
-        if $MY_PRINT_DEFAULTS xtrabackup | grep -q encrypt;then
+    if [ $encrypt -eq 0 ]; then
+        if $MY_PRINT_DEFAULTS xtrabackup | grep -q -- "--encrypt"; then
             wsrep_log_error "Unexpected option combination. SST may fail. Refer to http://www.percona.com/doc/percona-xtradb-cluster/manual/xtrabackup_sst.html"
         fi
         return
     fi
 
-    if [[ $sfmt == 'tar' ]];then
+    if [ $sfmt = 'tar' ]; then
         wsrep_log_info "NOTE: Xtrabackup-based encryption - encrypt=1 - cannot be enabled with tar format"
         encrypt=-1
         return
@@ -150,24 +148,24 @@ get_keys()
 
     wsrep_log_info "Xtrabackup based encryption enabled in my.cnf - Supported only from Xtrabackup 2.1.4"
 
-    if [[ -z $ealgo ]];then
+    if [ -z "$ealgo" ]; then
         wsrep_log_error "FATAL: Encryption algorithm empty from my.cnf, bailing out"
         exit 3
     fi
 
-    if [[ -z $ekey && ! -r $ekeyfile ]];then
+    if [ -z "$ekey" -a ! -r "$ekeyfile" ]; then
         wsrep_log_error "FATAL: Either key or keyfile must be readable"
         exit 3
     fi
 
-    if [[ -z $ekey ]];then
-        ecmd="${XBCRYPT_BIN} --encrypt-algo=$ealgo --encrypt-key-file=$ekeyfile"
+    if [ -z "$ekey" ]; then
+        ecmd="$XBCRYPT_BIN --encrypt-algo='$ealgo' --encrypt-key-file='$ekeyfile'"
     else
-        ecmd="${XBCRYPT_BIN} --encrypt-algo=$ealgo --encrypt-key=$ekey"
+        ecmd="$XBCRYPT_BIN --encrypt-algo='$ealgo' --encrypt-key='$ekey'"
     fi
 
-    if [[ "$WSREP_SST_OPT_ROLE" == "joiner" ]];then
-        ecmd+=" -d"
+    if [ "$WSREP_SST_OPT_ROLE" = 'joiner' ]; then
+        ecmd="$ecmd -d"
     fi
 
     stagemsg+="-XB-Encrypted"
@@ -175,17 +173,13 @@ get_keys()
 
 get_transfer()
 {
-    if [[ -z $SST_PORT ]];then
-        TSST_PORT=4444
-    else
-        TSST_PORT=$SST_PORT
-    fi
+    TSST_PORT="$SST_PORT"
 
     if [[ $tfmt == 'nc' ]];then
         wsrep_check_programs nc
         wsrep_log_info "Using netcat as streamer"
 
-        if [[ "$WSREP_SST_OPT_ROLE"  == "joiner" ]];then
+        if [[ "$WSREP_SST_OPT_ROLE" == "joiner" ]];then
             if nc -h 2>&1 | grep -q ncat;then
                 # Ncat
                 tcmd="nc -l ${TSST_PORT}"
@@ -213,7 +207,7 @@ get_transfer()
             # return an error if the flag is used.
             #
             tcmd_extra=""
-            if nc -h 2>&1 | grep -qw -- -N; then
+            if nc -h 2>&1 | grep -qw -- -N;then
                 tcmd_extra+="-N"
                 wsrep_log_info "Using nc -N"
             fi
@@ -244,44 +238,44 @@ get_transfer()
 
         if [[ $encrypt -eq 2 ]];then
             wsrep_log_info "Using openssl based encryption with socat: with crt and pem"
-            if [[ -z $tpem || -z $tcert ]];then
+            if [[ -z "$tpem" || -z "$tcert" ]];then
                 wsrep_log_error "Both PEM and CRT files required"
                 exit 22
             fi
             stagemsg+="-OpenSSL-Encrypted-2"
-            if [[ "$WSREP_SST_OPT_ROLE"  == "joiner" ]];then
+            if [[ "$WSREP_SST_OPT_ROLE" == "joiner" ]];then
                 wsrep_log_info "Decrypting with cert=${tpem}, cafile=${tcert}"
-                tcmd="socat -u openssl-listen:${TSST_PORT},reuseaddr,cert=${tpem},cafile=${tcert}${sockopt} stdio"
+                tcmd="socat -u openssl-listen:${TSST_PORT},reuseaddr,cert='${tpem}',cafile='${tcert}'${sockopt} stdio"
             else
                 wsrep_log_info "Encrypting with cert=${tpem}, cafile=${tcert}"
-                tcmd="socat -u stdio openssl-connect:${REMOTEIP}:${TSST_PORT},cert=${tpem},cafile=${tcert}${sockopt}"
+                tcmd="socat -u stdio openssl-connect:${REMOTEIP}:${TSST_PORT},cert='${tpem}',cafile='${tcert}'${sockopt}"
             fi
         elif [[ $encrypt -eq 3 ]];then
             wsrep_log_info "Using openssl based encryption with socat: with key and crt"
-            if [[ -z $tpem || -z $tkey ]];then
+            if [[ -z "$tpem" || -z "$tkey" ]];then
                 wsrep_log_error "Both certificate and key files required"
                 exit 22
             fi
             stagemsg+="-OpenSSL-Encrypted-3"
-            if [[ "$WSREP_SST_OPT_ROLE"  == "joiner" ]];then
-                if [[ -z $tcert ]];then
+            if [[ "$WSREP_SST_OPT_ROLE" == "joiner" ]];then
+                if [[ -z "$tcert" ]];then
                     wsrep_log_info "Decrypting with cert=${tpem}, key=${tkey}, verify=0"
-                    tcmd="socat -u openssl-listen:${TSST_PORT},reuseaddr,cert=${tpem},key=${tkey},verify=0${sockopt} stdio"
+                    tcmd="socat -u openssl-listen:${TSST_PORT},reuseaddr,cert='${tpem}',key='${tkey}',verify=0${sockopt} stdio"
                 else
                     wsrep_log_info "Decrypting with cert=${tpem}, key=${tkey}, cafile=${tcert}"
-                    tcmd="socat -u openssl-listen:${TSST_PORT},reuseaddr,cert=${tpem},key=${tkey},cafile=${tcert}${sockopt} stdio"
+                    tcmd="socat -u openssl-listen:${TSST_PORT},reuseaddr,cert='${tpem}',key='${tkey}',cafile='${tcert}'${sockopt} stdio"
                 fi
             else
-                if [[ -z $tcert ]];then
+                if [[ -z "$tcert" ]];then
                     wsrep_log_info "Encrypting with cert=${tpem}, key=${tkey}, verify=0"
-                    tcmd="socat -u stdio openssl-connect:${REMOTEIP}:${TSST_PORT},cert=${tpem},key=${tkey},verify=0${sockopt}"
+                    tcmd="socat -u stdio openssl-connect:${REMOTEIP}:${TSST_PORT},cert='${tpem}',key='${tkey}',verify=0${sockopt}"
                 else
                     wsrep_log_info "Encrypting with cert=${tpem}, key=${tkey}, cafile=${tcert}"
-                    tcmd="socat -u stdio openssl-connect:${REMOTEIP}:${TSST_PORT},cert=${tpem},key=${tkey},cafile=${tcert}${sockopt}"
+                    tcmd="socat -u stdio openssl-connect:${REMOTEIP}:${TSST_PORT},cert='${tpem}',key='${tkey}',cafile='${tcert}'${sockopt}"
                 fi
             fi
         else
-            if [[ "$WSREP_SST_OPT_ROLE"  == "joiner" ]];then
+            if [[ "$WSREP_SST_OPT_ROLE" == "joiner" ]];then
                 tcmd="socat -u TCP-LISTEN:${TSST_PORT},reuseaddr${sockopt} stdio"
             else
                 tcmd="socat -u stdio TCP:${REMOTEIP}:${TSST_PORT}${sockopt}"
@@ -290,24 +284,9 @@ get_transfer()
     fi
 }
 
-parse_cnf()
-{
-    local group=$1
-    local var=$2
-    # print the default settings for given group using my_print_default.
-    # normalize the variable names specified in cnf file (user can use _ or - for example log-bin or log_bin)
-    # then grep for needed variable
-    # finally get the variable value (if variables has been specified multiple time use the last value only)
-    reval=$($MY_PRINT_DEFAULTS $group | awk -F= '{if ($1 ~ /_/) { gsub(/_/,"-",$1); print $1"="$2 } else { print $0 }}' | grep -- "--$var=" | cut -d= -f2- | tail -1)
-    if [[ -z $reval ]];then
-        [[ -n $3 ]] && reval=$3
-    fi
-    echo $reval
-}
-
 get_footprint()
 {
-    pushd $WSREP_SST_OPT_DATA 1>/dev/null
+    pushd "$WSREP_SST_OPT_DATA" 1>/dev/null
     payload=$(find . -regex '.*\.ibd$\|.*\.MYI$\|.*\.MYD$\|.*ibdata1$' -type f -print0 | du --files0-from=- --block-size=1 -c | awk 'END { print $1 }')
     if $MY_PRINT_DEFAULTS xtrabackup | grep -q -- "--compress";then
         # QuickLZ has around 50% compression ratio
@@ -330,18 +309,18 @@ adjust_progress()
         return
     fi
 
-    if [[ -n $progress && $progress != '1' ]];then
-        if [[ -e $progress ]];then
-            pcmd+=" 2>>$progress"
+    if [ -n "$progress" -a "$progress" != '1' ]; then
+        if [ -e "$progress" ]; then
+            pcmd+=" 2>>'$progress'"
         else
-            pcmd+=" 2>$progress"
+            pcmd+=" 2>'$progress'"
         fi
-    elif [[ -z $progress && -n $rlimit  ]];then
+    elif [ -z "$progress" -a -n "$rlimit" ]; then
             # When rlimit is non-zero
             pcmd="pv -q"
     fi
 
-    if [[ -n $rlimit && "$WSREP_SST_OPT_ROLE"  == "donor" ]];then
+    if [ -n "$rlimit" -a "$WSREP_SST_OPT_ROLE" = 'donor' ]; then
         wsrep_log_info "Rate-limiting SST to $rlimit"
         pcmd+=" -L \$rlimit"
     fi
@@ -351,29 +330,35 @@ read_cnf()
 {
     sfmt=$(parse_cnf sst streamfmt "xbstream")
     tfmt=$(parse_cnf sst transferfmt "socat")
-    tcert=$(parse_cnf sst tca "")
-    tpem=$(parse_cnf sst tcert "")
-    tkey=$(parse_cnf sst tkey "")
+
     encrypt=$(parse_cnf sst encrypt 0)
+    if [ $encrypt -ge 2 ]; then
+        tcert=$(parse_cnf sst tca "")
+        tpem=$(parse_cnf sst tcert "")
+        if [ $encrypt -ge 3 ]; then
+            tkey=$(parse_cnf sst tkey "")
+        fi
+    elif [ $encrypt -ne -1 ]; then
+        # Refer to http://www.percona.com/doc/percona-xtradb-cluster/manual/xtrabackup_sst.html
+        ealgo=$(parse_cnf xtrabackup encrypt "")
+        if [ -z "$ealgo" ]; then
+            ealgo=$(parse_cnf sst encrypt-algo "")
+            ekey=$(parse_cnf sst encrypt-key "")
+            ekeyfile=$(parse_cnf sst encrypt-key-file "")
+        else
+            ekey=$(parse_cnf xtrabackup encrypt-key "")
+            ekeyfile=$(parse_cnf xtrabackup encrypt-key-file "")
+        fi
+    fi
+
     sockopt=$(parse_cnf sst sockopt "")
     progress=$(parse_cnf sst progress "")
-    rebuild=$(parse_cnf sst rebuild 0)
     ttime=$(parse_cnf sst time 0)
     cpat=$(parse_cnf sst cpat '.*galera\.cache$\|.*sst_in_progress$\|.*\.sst$\|.*gvwstate\.dat$\|.*grastate\.dat$\|.*\.err$\|.*\.log$\|.*RPM_UPGRADE_MARKER$\|.*RPM_UPGRADE_HISTORY$')
     [[ $OS == "FreeBSD" ]] && cpat=$(parse_cnf sst cpat '.*galera\.cache$|.*sst_in_progress$|.*\.sst$|.*gvwstate\.dat$|.*grastate\.dat$|.*\.err$|.*\.log$|.*RPM_UPGRADE_MARKER$|.*RPM_UPGRADE_HISTORY$')
-    ealgo=$(parse_cnf xtrabackup encrypt "")
-    ekey=$(parse_cnf xtrabackup encrypt-key "")
-    ekeyfile=$(parse_cnf xtrabackup encrypt-key-file "")
     scomp=$(parse_cnf sst compressor "")
     sdecomp=$(parse_cnf sst decompressor "")
 
-    # Refer to http://www.percona.com/doc/percona-xtradb-cluster/manual/xtrabackup_sst.html
-    if [[ -z $ealgo ]];then
-        ealgo=$(parse_cnf sst encrypt-algo "")
-        ekey=$(parse_cnf sst encrypt-key "")
-        ekeyfile=$(parse_cnf sst encrypt-key-file "")
-    fi
-
     rlimit=$(parse_cnf sst rlimit "")
     uextra=$(parse_cnf sst use-extra 0)
     speciald=$(parse_cnf sst sst-special-dirs 1)
@@ -393,7 +378,7 @@ read_cnf()
     fi
 
     if [[ $ssyslog -ne -1 ]];then
-        if $MY_PRINT_DEFAULTS mysqld_safe | tr '_' '-' | grep -q -- "--syslog";then
+        if $MY_PRINT_DEFAULTS mysqld_safe | grep -q -- "--syslog";then
             ssyslog=1
         fi
     fi
@@ -407,20 +392,20 @@ read_cnf()
 
 get_stream()
 {
-    if [[ $sfmt == 'mbstream' || $sfmt == 'xbstream' ]];then
+    if [ "$sfmt" = 'mbstream' -o "$sfmt" = 'xbstream' ]; then
         wsrep_log_info "Streaming with ${sfmt}"
-        if [[ "$WSREP_SST_OPT_ROLE"  == "joiner" ]];then
-            strmcmd="${XBSTREAM_BIN} -x"
+        if [ "$WSREP_SST_OPT_ROLE" = 'joiner' ]; then
+            strmcmd="$XBSTREAM_BIN -x"
         else
-            strmcmd="${XBSTREAM_BIN} -c \${INFO_FILE}"
+            strmcmd="$XBSTREAM_BIN -c '$INFO_FILE'"
         fi
     else
         sfmt="tar"
         wsrep_log_info "Streaming with tar"
-        if [[ "$WSREP_SST_OPT_ROLE"  == "joiner" ]];then
-            strmcmd="tar xfi - "
+        if [ "$WSREP_SST_OPT_ROLE" = 'joiner' ]]; then
+            strmcmd="tar xfi -"
         else
-            strmcmd="tar cf - \${INFO_FILE} "
+            strmcmd="tar cf - '$INFO_FILE'"
         fi
     fi
 }
@@ -443,19 +428,19 @@ cleanup_joiner()
 {
     # Since this is invoked just after exit NNN
     local estatus=$?
-    if [[ $estatus -ne 0 ]];then
+    if [ $estatus -ne 0 ]; then
         wsrep_log_error "Cleanup after exit with status:$estatus"
-    elif [ "${WSREP_SST_OPT_ROLE}" = "joiner" ];then
+    elif [ "${WSREP_SST_OPT_ROLE}" = 'joiner' ]; then
         wsrep_log_info "Removing the sst_in_progress file"
         wsrep_cleanup_progress_file
     fi
-    if [[ -n $progress && -p $progress ]];then
+    if [ -n "$progress" -a -p "$progress" ]; then
         wsrep_log_info "Cleaning up fifo file $progress"
-        rm $progress
+        rm "$progress"
     fi
 
-    if [[ -n ${STATDIR:-} ]];then
-       [[ -d $STATDIR ]] && rm -rf $STATDIR
+    if [ -n "$STATDIR" ]; then
+       [ -d "$STATDIR" ] && rm -rf "$STATDIR"
     fi
 
     # Final cleanup
@@ -484,11 +469,11 @@ cleanup_donor()
 {
     # Since this is invoked just after exit NNN
     local estatus=$?
-    if [[ $estatus -ne 0 ]];then
+    if [ $estatus -ne 0 ]; then
         wsrep_log_error "Cleanup after exit with status:$estatus"
     fi
 
-    if [[ -n ${XTRABACKUP_PID:-} ]];then
+    if [ -n "$XTRABACKUP_PID" ]; then
         if check_pid $XTRABACKUP_PID
         then
             wsrep_log_error "xtrabackup process is still running. Killing..."
@@ -496,21 +481,21 @@ cleanup_donor()
         fi
     fi
 
-    rm -f ${DATA}/${IST_FILE} || true
+    rm -f "$DATA/$IST_FILE" || true
 
-    if [[ -n $progress && -p $progress ]];then
+    if [ -n "$progress" -a -p "$progress" ]; then
         wsrep_log_info "Cleaning up fifo file $progress"
-        rm -f $progress || true
+        rm -f "$progress" || true
     fi
 
     wsrep_log_info "Cleaning up temporary directories"
 
-    if [[ -n $xtmpdir ]];then
-       [[ -d $xtmpdir ]] &&  rm -rf $xtmpdir || true
+    if [ -n "$xtmpdir" ]; then
+       [ -d "$xtmpdir" ] && rm -rf "$xtmpdir" || true
     fi
 
-    if [[ -n $itmpdir ]];then
-       [[ -d $itmpdir ]] &&  rm -rf $itmpdir || true
+    if [ -n "$itmpdir" ]; then
+       [ -d "$itmpdir" ] && rm -rf "$itmpdir" || true
     fi
 
     # Final cleanup
@@ -531,7 +516,7 @@ cleanup_donor()
 
 kill_xtrabackup()
 {
-    local PID=$(cat $XTRABACKUP_PID)
+    local PID=$(cat "$XTRABACKUP_PID")
     [ -n "$PID" -a "0" != "$PID" ] && kill $PID && (kill $PID && kill -9 $PID) || :
     wsrep_log_info "Removing xtrabackup pid file $XTRABACKUP_PID"
     rm -f "$XTRABACKUP_PID" || true
@@ -539,11 +524,11 @@ kill_xtrabackup()
 
 setup_ports()
 {
-    SST_PORT=${WSREP_SST_OPT_ADDR_PORT}
-    if [[ "$WSREP_SST_OPT_ROLE"  == "donor" ]];then
-        REMOTEIP=${WSREP_SST_OPT_HOST}
-        lsn=${WSREP_SST_OPT_LSN}
-        sst_ver=${WSREP_SST_OPT_SST_VER}
+    SST_PORT="$WSREP_SST_OPT_PORT"
+    if [ "$WSREP_SST_OPT_ROLE" = "donor" ]; then
+        REMOTEIP="${WSREP_SST_OPT_HOST}"
+        lsn="${WSREP_SST_OPT_LSN}"
+        sst_ver="${WSREP_SST_OPT_SST_VER}"
     fi
 }
 
@@ -551,9 +536,9 @@ setup_ports()
 # (regardless of timeout)
 wait_for_listen()
 {
-    local PORT=$1
-    local ADDR=$2
-    local MODULE=$3
+    local PORT="$1"
+    local ADDR="$2"
+    local MODULE="$3"
     for i in {1..50}
     do
         if [ "$OS" = "FreeBSD" ];then
@@ -569,10 +554,11 @@ wait_for_listen()
 check_extra()
 {
     local use_socket=1
-    if [[ $uextra -eq 1 ]];then
-        if $MY_PRINT_DEFAULTS --mysqld | tr '_' '-' | grep -- "--thread-handling=" | grep -q 'pool-of-threads';then
-            local eport=$($MY_PRINT_DEFAULTS --mysqld | tr '_' '-' | grep -- "--extra-port=" | cut -d= -f2)
-            if [[ -n $eport ]];then
+    if [ $uextra -eq 1 ]; then
+        local thread_handling=$(parse_cnf --mysqld thread-handling "")
+        if [ $thread_handling -eq "pool-of-threads" ];then
+            local eport=$(parse_cnf --mysqld extra-port "")
+            if [ -n "$eport" ]; then
                 # Xtrabackup works only locally.
                 # Hence, setting host to 127.0.0.1 unconditionally.
                 wsrep_log_info "SST through extra_port $eport"
@@ -586,25 +572,25 @@ check_extra()
             wsrep_log_info "Thread pool not set, ignore the option use_extra"
         fi
     fi
-    if [[ $use_socket -eq 1 ]] && [[ -n "$WSREP_SST_OPT_SOCKET" ]];then
-        INNOEXTRA+=" --socket=$WSREP_SST_OPT_SOCKET"
+    if [ $use_socket -eq 1 -a -n "$WSREP_SST_OPT_SOCKET" ]; then
+        INNOEXTRA+=" --socket='$WSREP_SST_OPT_SOCKET'"
     fi
 }
 
 recv_joiner()
 {
-    local dir=$1
-    local msg=$2
+    local dir="$1"
+    local msg="$2"
     local tmt=$3
     local checkf=$4
     local ltcmd
 
-    if [[ ! -d ${dir} ]];then
+    if [ ! -d "$dir" ]; then
         # This indicates that IST is in progress
         return
     fi
 
-    pushd ${dir} 1>/dev/null
+    pushd "$dir" 1>/dev/null
     set +e
 
     if [[ $tmt -gt 0 ]] && command -v timeout >/dev/null;then
@@ -646,10 +632,10 @@ recv_joiner()
 
 send_donor()
 {
-    local dir=$1
-    local msg=$2
+    local dir="$1"
+    local msg="$2"
 
-    pushd ${dir} 1>/dev/null
+    pushd "$dir" 1>/dev/null
     set +e
     timeit "$msg" "$strmcmd | $tcmd; RC=( "\${PIPESTATUS[@]}" )"
     set -e
@@ -680,11 +666,11 @@ monitor_process()
     done
 }
 
-wsrep_check_programs "$INNOBACKUPEX_BIN"
+wsrep_check_programs "$MARIABACKUP_BIN"
 
 rm -f "${MAGIC_FILE}"
 
-if [[ ! ${WSREP_SST_OPT_ROLE} == 'joiner' && ! ${WSREP_SST_OPT_ROLE} == 'donor' ]];then
+if [ ! "$WSREP_SST_OPT_ROLE" = 'joiner' -a ! "$WSREP_SST_OPT_ROLE" = 'donor' ]; then
     wsrep_log_error "Invalid role ${WSREP_SST_OPT_ROLE}"
     exit 22
 fi
@@ -692,42 +678,29 @@ fi
 read_cnf
 setup_ports
 
-if ${INNOBACKUPEX_BIN} /tmp --help 2>/dev/null | grep -q -- '--version-check'; then
-    disver="--no-version-check"
+if "${MARIABACKUP_BIN}" --help 2>/dev/null | grep -q -- '--version-check'; then
+    disver='--no-version-check'
 fi
 
-iopts+=" --databases-exclude=\"lost+found\""
+iopts+=" --databases-exclude='lost+found'"
 
-if [[ ${FORCE_FTWRL:-0} -eq 1 ]];then
+if [ ${FORCE_FTWRL:-0} -eq 1 ]; then
     wsrep_log_info "Forcing FTWRL due to environment variable FORCE_FTWRL equal to $FORCE_FTWRL"
-    iopts+=" --no-backup-locks"
+    iopts+=' --no-backup-locks'
 fi
 
-INNOEXTRA=$WSREP_SST_OPT_MYSQLD
-
-INNODB_DATA_HOME_DIR=${INNODB_DATA_HOME_DIR:-""}
-# Try to set INNODB_DATA_HOME_DIR from the command line:
-if [ ! -z "$INNODB_DATA_HOME_DIR_ARG" ]; then
-    INNODB_DATA_HOME_DIR=$INNODB_DATA_HOME_DIR_ARG
-fi
 # if no command line arg and INNODB_DATA_HOME_DIR environment variable
 # is not set, try to get it from my.cnf:
 if [ -z "$INNODB_DATA_HOME_DIR" ]; then
-    INNODB_DATA_HOME_DIR=$(parse_cnf mysqld$WSREP_SST_OPT_SUFFIX_VALUE innodb-data-home-dir '')
-fi
-if [ -z "$INNODB_DATA_HOME_DIR" ]; then
-    INNODB_DATA_HOME_DIR=$(parse_cnf --mysqld innodb-data-home-dir '')
-fi
-if [ ! -z "$INNODB_DATA_HOME_DIR" ]; then
-   INNOEXTRA+=" --innodb-data-home-dir=$INNODB_DATA_HOME_DIR"
+    INNODB_DATA_HOME_DIR=$(parse_cnf --mysqld innodb-data-home-dir)
 fi
 
 if [ -n "$INNODB_DATA_HOME_DIR" ]; then
     # handle both relative and absolute paths
-    INNODB_DATA_HOME_DIR=$(cd $DATA; mkdir -p "$INNODB_DATA_HOME_DIR"; cd $INNODB_DATA_HOME_DIR; pwd -P)
+    INNODB_DATA_HOME_DIR=$(cd "$DATA"; mkdir -p "$INNODB_DATA_HOME_DIR"; cd "$INNODB_DATA_HOME_DIR"; pwd -P)
 else
     # default to datadir
-    INNODB_DATA_HOME_DIR=$(cd $DATA; pwd -P)
+    INNODB_DATA_HOME_DIR=$(cd "$DATA"; pwd -P)
 fi
 
 if [[ $ssyslog -eq 1 ]];then
@@ -735,25 +708,25 @@ if [[ $ssyslog -eq 1 ]];then
     if ! command -v logger >/dev/null;then
         wsrep_log_error "logger not in path: $PATH. Ignoring"
     else
-        wsrep_log_info "Logging all stderr of SST/Innobackupex to syslog"
+        wsrep_log_info "Logging all stderr of SST/mariabackup to syslog"
 
         exec 2> >(logger -p daemon.err -t ${ssystag}wsrep-sst-$WSREP_SST_OPT_ROLE)
 
         wsrep_log_error()
         {
-            logger  -p daemon.err -t ${ssystag}wsrep-sst-$WSREP_SST_OPT_ROLE "$@"
+            logger -p daemon.err -t ${ssystag}wsrep-sst-$WSREP_SST_OPT_ROLE "$@"
         }
 
         wsrep_log_info()
         {
-            logger  -p daemon.info -t ${ssystag}wsrep-sst-$WSREP_SST_OPT_ROLE "$@"
+            logger -p daemon.info -t ${ssystag}wsrep-sst-$WSREP_SST_OPT_ROLE "$@"
         }
-
-        INNOAPPLY="${INNOBACKUPEX_BIN} --prepare $disver $iapts \$INNOEXTRA $rebuildcmd --target-dir=\${DATA} 2>&1 | logger -p daemon.err -t ${ssystag}innobackupex-apply"
-        INNOMOVE="${INNOBACKUPEX_BIN} ${WSREP_SST_OPT_CONF} --move-back $disver $impts --force-non-empty-directories --target-dir=\${DATA} 2>&1 | logger -p daemon.err -t ${ssystag}innobackupex-move"
-        INNOBACKUP="${INNOBACKUPEX_BIN} ${WSREP_SST_OPT_CONF} --backup $disver $iopts \$tmpopts \$INNOEXTRA --galera-info --stream=\$sfmt --target-dir=\$itmpdir 2> >(logger -p daemon.err -t ${ssystag}innobackupex-backup)"
     fi
 
+    INNOAPPLY="2>&1 | logger -p daemon.err -t ${ssystag}innobackupex-apply"
+    INNOMOVE="2>&1 | logger -p daemon.err -t ${ssystag}innobackupex-move"
+    INNOBACKUP="2> >(logger -p daemon.err -t ${ssystag}innobackupex-backup)"
+
 else
 
 if [[ "$sstlogarchive" -eq 1 ]]
@@ -761,62 +734,71 @@ then
     ARCHIVETIMESTAMP=$(date "+%Y.%m.%d-%H.%M.%S.%N")
     newfile=""
 
-    if [[ ! -z "$sstlogarchivedir" ]]
+    if [ -n "$sstlogarchivedir" ]
     then
-        if [[ ! -d "$sstlogarchivedir" ]]
+        if [ ! -d "$sstlogarchivedir" ]
         then
             mkdir -p "$sstlogarchivedir"
         fi
     fi
 
-    if [ -e "${INNOAPPLYLOG}" ]
+    if [ -e "$INNOAPPLYLOG" ]
     then
-        if [[ ! -z "$sstlogarchivedir" ]]
+        if [ -n "$sstlogarchivedir" ]
         then
-            newfile=$sstlogarchivedir/$(basename "${INNOAPPLYLOG}").${ARCHIVETIMESTAMP}
+            newfile="$sstlogarchivedir/$(basename '$INNOAPPLYLOG').$ARCHIVETIMESTAMP"
         else
-            newfile=${INNOAPPLYLOG}.${ARCHIVETIMESTAMP}
+            newfile="$INNOAPPLYLOG.$ARCHIVETIMESTAMP"
         fi
         wsrep_log_info "Moving ${INNOAPPLYLOG} to ${newfile}"
-        mv "${INNOAPPLYLOG}" "${newfile}"
-        gzip "${newfile}"
+        mv "$INNOAPPLYLOG" "$newfile"
+        gzip "$newfile"
     fi
 
-    if [ -e "${INNOMOVELOG}" ]
+    if [ -e "$INNOMOVELOG" ]
     then
-        if [[ ! -z "$sstlogarchivedir" ]]
+        if [ -n "$sstlogarchivedir" ]
         then
-            newfile=$sstlogarchivedir/$(basename "${INNOMOVELOG}").${ARCHIVETIMESTAMP}
+            newfile="$sstlogarchivedir/$(basename '$INNOMOVELOG').$ARCHIVETIMESTAMP"
         else
-            newfile=${INNOMOVELOG}.${ARCHIVETIMESTAMP}
+            newfile="$INNOMOVELOG.$ARCHIVETIMESTAMP"
         fi
-
         wsrep_log_info "Moving ${INNOMOVELOG} to ${newfile}"
-        mv "${INNOMOVELOG}" "${newfile}"
-        gzip "${newfile}"
+        mv "$INNOMOVELOG" "$newfile"
+        gzip "$newfile"
     fi
 
-    if [ -e "${INNOBACKUPLOG}" ]
+    if [ -e "$INNOBACKUPLOG" ]
     then
-        if [[ ! -z "$sstlogarchivedir" ]]
+        if [ -n "$sstlogarchivedir" ]
         then
-            newfile=$sstlogarchivedir/$(basename "${INNOBACKUPLOG}").${ARCHIVETIMESTAMP}
+            newfile="$sstlogarchivedir/$(basename '$INNOBACKUPLOG').$ARCHIVETIMESTAMP"
         else
-            newfile=${INNOBACKUPLOG}.${ARCHIVETIMESTAMP}
+            newfile="$INNOBACKUPLOG.$ARCHIVETIMESTAMP"
         fi
-
         wsrep_log_info "Moving ${INNOBACKUPLOG} to ${newfile}"
-        mv "${INNOBACKUPLOG}" "${newfile}"
-        gzip "${newfile}"
+        mv "$INNOBACKUPLOG" "$newfile"
+        gzip "$newfile"
     fi
 fi
 
-    INNOAPPLY="${INNOBACKUPEX_BIN} --prepare $disver $iapts \$INNOEXTRA $rebuildcmd --target-dir=\${DATA} &> ${INNOAPPLYLOG}"
-    INNOMOVE="${INNOBACKUPEX_BIN} ${WSREP_SST_OPT_CONF} --move-back $disver $impts --force-non-empty-directories --target-dir=\${DATA} &> ${INNOMOVELOG}"
-    INNOBACKUP="${INNOBACKUPEX_BIN} ${WSREP_SST_OPT_CONF} --backup $disver $iopts \$tmpopts \$INNOEXTRA --galera-info --stream=\$sfmt --target-dir=\$itmpdir 2> ${INNOBACKUPLOG}"
+    INNOAPPLY="&> '$INNOAPPLYLOG'"
+    INNOMOVE="&> '$INNOMOVELOG'"
+    INNOBACKUP="2> '$INNOBACKUPLOG'"
 
 fi
 
+setup_commands()
+{
+    local mysqld_args=""
+    if [ -n "$WSREP_SST_OPT_MYSQLD" ]; then
+        mysqld_args="--mysqld-args $WSREP_SST_OPT_MYSQLD"
+    fi
+    INNOAPPLY="$MARIABACKUP_BIN --prepare $disver $iapts $INNOEXTRA --target-dir='$DATA' --datadir='$DATA' $mysqld_args $INNOAPPLY"
+    INNOMOVE="$MARIABACKUP_BIN $WSREP_SST_OPT_CONF --move-back $disver $impts --force-non-empty-directories --target-dir='$DATA' --datadir='${TDATA:-$DATA}' $INNOMOVE"
+    INNOBACKUP="$MARIABACKUP_BIN $WSREP_SST_OPT_CONF --backup $disver $iopts $tmpopts $INNOEXTRA --galera-info --stream='$sfmt' --target-dir='$itmpdir' --datadir='$DATA' $mysqld_args $INNOBACKUP"
+}
+
 get_stream
 get_transfer
 
@@ -827,71 +809,61 @@ then
     if [ $WSREP_SST_OPT_BYPASS -eq 0 ]
     then
         usrst=0
-        if [[ -z $sst_ver ]];then
+        if [ -z "$sst_ver" ]; then
             wsrep_log_error "Upgrade joiner to 5.6.21 or higher for backup locks support"
             wsrep_log_error "The joiner is not supported for this version of donor"
             exit 93
         fi
 
-        if [[ -z $(parse_cnf mysqld$WSREP_SST_OPT_SUFFIX_VALUE tmpdir "") && \
-              -z $(parse_cnf --mysqld tmpdir "") && \
-              -z $(parse_cnf xtrabackup tmpdir "") ]]; then
+        if [ -z "$(parse_cnf --mysqld tmpdir)" -a \
+             -z "$(parse_cnf xtrabackup tmpdir)" ]; then
             xtmpdir=$(mktemp -d)
-            tmpopts="--tmpdir=$xtmpdir"
+            tmpopts="--tmpdir='$xtmpdir'"
             wsrep_log_info "Using $xtmpdir as xtrabackup temporary directory"
         fi
 
         itmpdir=$(mktemp -d)
-        wsrep_log_info "Using $itmpdir as innobackupex temporary directory"
+        wsrep_log_info "Using $itmpdir as mariabackup temporary directory"
 
-        if [[ -n "${WSREP_SST_OPT_USER:-}" && "$WSREP_SST_OPT_USER" != "(null)" ]]; then
-           INNOEXTRA+=" --user=$WSREP_SST_OPT_USER"
+        if [ -n "$WSREP_SST_OPT_USER" -a "$WSREP_SST_OPT_USER" != '(null)' ]; then
+           INNOEXTRA+=" --user='$WSREP_SST_OPT_USER'"
            usrst=1
         fi
 
-        if [ -n "${WSREP_SST_OPT_PSWD:-}" ]; then
-            export MYSQL_PWD=$WSREP_SST_OPT_PSWD
-        elif [[ $usrst -eq 1 ]];then
+        if [ -n "$WSREP_SST_OPT_PSWD" ]; then
+            export MYSQL_PWD="$WSREP_SST_OPT_PSWD"
+        elif [ $usrst -eq 1 ]; then
             # Empty password, used for testing, debugging etc.
             unset MYSQL_PWD
         fi
 
-        get_keys
-        if [[ $encrypt -eq 1 ]];then
-            if [[ -n $ekey ]];then
-                INNOEXTRA+=" --encrypt=$ealgo --encrypt-key=$ekey"
-            else
-                INNOEXTRA+=" --encrypt=$ealgo --encrypt-key-file=$ekeyfile"
-            fi
-        fi
-
         check_extra
 
         wsrep_log_info "Streaming GTID file before SST"
 
         # Store donor's wsrep GTID (state ID) and wsrep_gtid_domain_id
         # (separated by a space).
-        echo "${WSREP_SST_OPT_GTID} ${WSREP_SST_OPT_GTID_DOMAIN_ID}" > "${MAGIC_FILE}"
+        echo "$WSREP_SST_OPT_GTID $WSREP_SST_OPT_GTID_DOMAIN_ID" > "$MAGIC_FILE"
 
         ttcmd="$tcmd"
 
-        if [[ $encrypt -eq 1 ]];then
-            if [[ -n $scomp ]];then
-                tcmd=" $ecmd | $scomp | $tcmd "
-            else
-                tcmd=" $ecmd | $tcmd "
-            fi
-        elif [[ -n $scomp ]];then
-            tcmd=" $scomp | $tcmd "
+        if [ -n "$scomp" ]; then
+            tcmd="$scomp | $tcmd"
         fi
 
-        send_donor $DATA "${stagemsg}-gtid"
+        get_keys
+        if [ $encrypt -eq 1 ]; then
+            tcmd="$ecmd | $tcmd"
+        fi
+
+        send_donor "$DATA" "${stagemsg}-gtid"
 
         tcmd="$ttcmd"
-        if [[ -n $progress ]];then
+
+        if [ -n "$progress" ]; then
             get_footprint
             tcmd="$pcmd | $tcmd"
-        elif [[ -n $rlimit ]];then
+        elif [ -n "$rlimit" ]; then
             adjust_progress
             tcmd="$pcmd | $tcmd"
         fi
@@ -899,18 +871,19 @@ then
         wsrep_log_info "Sleeping before data transfer for SST"
         sleep 10
 
-        wsrep_log_info "Streaming the backup to joiner at ${REMOTEIP} ${SST_PORT:-4444}"
+        wsrep_log_info "Streaming the backup to joiner at ${REMOTEIP}:${SST_PORT}"
 
-        if [[ -n $scomp ]];then
+        if [ -n "$scomp" ]; then
             tcmd="$scomp | $tcmd"
         fi
 
+        setup_commands
         set +e
         timeit "${stagemsg}-SST" "$INNOBACKUP | $tcmd; RC=( "\${PIPESTATUS[@]}" )"
         set -e
 
         if [ ${RC[0]} -ne 0 ]; then
-          wsrep_log_error "${INNOBACKUPEX_BIN} finished with error: ${RC[0]}. " \
+          wsrep_log_error "${MARIABACKUP_BIN} finished with error: ${RC[0]}. " \
                           "Check syslog or ${INNOBACKUPLOG} for details"
           exit 22
         elif [[ ${RC[$(( ${#RC[@]}-1 ))]} -eq 1 ]];then
@@ -918,7 +891,7 @@ then
           exit 22
         fi
 
-        # innobackupex implicitly writes PID to fixed location in $xtmpdir
+        # mariabackup implicitly writes PID to fixed location in $xtmpdir
         XTRABACKUP_PID="$xtmpdir/xtrabackup_pid"
 
     else # BYPASS FOR IST
@@ -928,21 +901,21 @@ then
 
         # Store donor's wsrep GTID (state ID) and wsrep_gtid_domain_id
         # (separated by a space).
-        echo "${WSREP_SST_OPT_GTID} ${WSREP_SST_OPT_GTID_DOMAIN_ID}" > "${MAGIC_FILE}"
-        echo "1" > "${DATA}/${IST_FILE}"
+        echo "$WSREP_SST_OPT_GTID $WSREP_SST_OPT_GTID_DOMAIN_ID" > "$MAGIC_FILE"
+        echo "1" > "$DATA/$IST_FILE"
+
+        if [ -n "$scomp" ]; then
+            tcmd="$scomp | $tcmd"
+        fi
+
         get_keys
-        if [[ $encrypt -eq 1 ]];then
-            if [[ -n $scomp ]];then
-                tcmd=" $ecmd | $scomp | $tcmd "
-            else
-                tcmd=" $ecmd | $tcmd "
-            fi
-        elif [[ -n $scomp ]];then
-            tcmd=" $scomp | $tcmd "
+        if [ $encrypt -eq 1 ]; then
+            tcmd="$ecmd | $tcmd"
         fi
-        strmcmd+=" \${IST_FILE}"
 
-        send_donor $DATA "${stagemsg}-IST"
+        strmcmd+=" '$IST_FILE'"
+
+        send_donor "$DATA" "${stagemsg}-IST"
 
     fi
 
@@ -951,37 +924,26 @@ then
 
 elif [ "${WSREP_SST_OPT_ROLE}" = "joiner" ]
 then
-    [[ -e $SST_PROGRESS_FILE ]] && wsrep_log_info "Stale sst_in_progress file: $SST_PROGRESS_FILE"
-    [[ -n $SST_PROGRESS_FILE ]] && touch $SST_PROGRESS_FILE
+    [[ -e "$SST_PROGRESS_FILE" ]] && wsrep_log_info "Stale sst_in_progress file: $SST_PROGRESS_FILE"
+    [[ -n "$SST_PROGRESS_FILE" ]] && touch "$SST_PROGRESS_FILE"
 
-    ib_home_dir=$INNODB_DATA_HOME_DIR
+    ib_home_dir="$INNODB_DATA_HOME_DIR"
 
-    WSREP_LOG_DIR=${WSREP_LOG_DIR:-""}
-    # Try to set WSREP_LOG_DIR from the command line:
-    if [ ! -z "$INNODB_LOG_GROUP_HOME_ARG" ]; then
-        WSREP_LOG_DIR=$INNODB_LOG_GROUP_HOME_ARG
-    fi
-    # if no command line arg and WSREP_LOG_DIR is not set,
+    # if no command line argument and INNODB_LOG_GROUP_HOME is not set,
     # try to get it from my.cnf:
-    if [ -z "$WSREP_LOG_DIR" ]; then
-        WSREP_LOG_DIR=$(parse_cnf mysqld$WSREP_SST_OPT_SUFFIX_VALUE innodb-log-group-home-dir '')
-    fi
-    if [ -z "$WSREP_LOG_DIR" ]; then
-        WSREP_LOG_DIR=$(parse_cnf --mysqld innodb-log-group-home-dir '')
+    if [ -z "$INNODB_LOG_GROUP_HOME" ]; then
+        INNODB_LOG_GROUP_HOME=$(parse_cnf --mysqld innodb-log-group-home-dir)
     fi
 
-    ib_log_dir=$WSREP_LOG_DIR
+    ib_log_dir="$INNODB_LOG_GROUP_HOME"
 
-    # Try to set ib_undo_dir from the command line:
-    ib_undo_dir=${INNODB_UNDO_DIR_ARG:-""}
     # if no command line arg then try to get it from my.cnf:
-    if [ -z "$ib_undo_dir" ]; then
-        ib_undo_dir=$(parse_cnf mysqld$WSREP_SST_OPT_SUFFIX_VALUE innodb-undo-directory "")
-    fi
-    if [ -z "$ib_undo_dir" ]; then
-        ib_undo_dir=$(parse_cnf --mysqld innodb-undo-directory "")
+    if [ -z "$INNODB_UNDO_DIR" ]; then
+        INNODB_UNDO_DIR=$(parse_cnf --mysqld innodb-undo-directory)
     fi
 
+    ib_undo_dir="$INNODB_UNDO_DIR"
+
     stagemsg="Joiner-Recv"
 
     sencrypted=1
@@ -989,46 +951,37 @@ then
 
     MODULE="xtrabackup_sst"
 
-    rm -f "${DATA}/${IST_FILE}"
+    rm -f "$DATA/$IST_FILE"
 
     # May need xtrabackup_checkpoints later on
-    rm -f ${DATA}/xtrabackup_binary ${DATA}/xtrabackup_galera_info  ${DATA}/ib_logfile0
+    rm -f "$DATA/xtrabackup_binary" "$DATA/xtrabackup_galera_info" "$DATA/ib_logfile0"
 
-    ADDR=${WSREP_SST_OPT_ADDR}
-    if [ -z "${SST_PORT}" ]
-    then
-        SST_PORT=4444
-        if [ "${ADDR#\[}" != "$ADDR" ]; then
-            ADDR="$(echo ${WSREP_SST_OPT_ADDR} | awk -F '\\]:' '{ print $1 }')]:${SST_PORT}"
-        else
-            ADDR="$(echo ${WSREP_SST_OPT_ADDR} | awk -F ':' '{ print $1 }'):${SST_PORT}"
-        fi
-    fi
+    ADDR="$WSREP_SST_OPT_ADDR"
 
-    wait_for_listen ${SST_PORT} ${ADDR} ${MODULE} &
+    wait_for_listen "$SST_PORT" "$ADDR" "$MODULE" &
 
     trap sig_joiner_cleanup HUP PIPE INT TERM
     trap cleanup_joiner EXIT
 
-    if [[ -n $progress ]];then
+    if [ -n "$progress" ]; then
         adjust_progress
         tcmd+=" | $pcmd"
     fi
 
     get_keys
-    if [[ $encrypt -eq 1 && $sencrypted -eq 1 ]];then
-        if [[ -n $sdecomp ]];then
-            strmcmd=" $sdecomp | $ecmd | $strmcmd"
+    if [ $encrypt -eq 1 -a $sencrypted -eq 1 ]; then
+        if [ -n "$sdecomp" ]; then
+            strmcmd="$sdecomp | $ecmd | $strmcmd"
         else
-            strmcmd=" $ecmd | $strmcmd"
+            strmcmd="$ecmd | $strmcmd"
         fi
-    elif [[ -n $sdecomp ]];then
-            strmcmd=" $sdecomp | $strmcmd"
+    elif [ -n "$sdecomp" ]; then
+            strmcmd="$sdecomp | $strmcmd"
     fi
 
     STATDIR=$(mktemp -d)
-    MAGIC_FILE="${STATDIR}/${INFO_FILE}"
-    recv_joiner $STATDIR "${stagemsg}-gtid" $stimeout 1
+    MAGIC_FILE="$STATDIR/$INFO_FILE"
+    recv_joiner "$STATDIR" "${stagemsg}-gtid" $stimeout 1
 
     if ! ps -p ${WSREP_SST_OPT_PARENT} &>/dev/null
     then
@@ -1036,71 +989,63 @@ then
         exit 32
     fi
 
-    if [ ! -r "${STATDIR}/${IST_FILE}" ]
+    if [ ! -r "$STATDIR/$IST_FILE" ]
     then
 
-        if [[ -d ${DATA}/.sst ]];then
+        if [ -d "$DATA/.sst" ]; then
             wsrep_log_info "WARNING: Stale temporary SST directory: ${DATA}/.sst from previous state transfer. Removing"
-            rm -rf ${DATA}/.sst
+            rm -rf "$DATA/.sst"
         fi
-        mkdir -p ${DATA}/.sst
-        (recv_joiner $DATA/.sst "${stagemsg}-SST" 0 0) &
+        mkdir -p "$DATA/.sst"
+        (recv_joiner "$DATA/.sst" "${stagemsg}-SST" 0 0) &
         jpid=$!
         wsrep_log_info "Proceeding with SST"
 
         wsrep_log_info "Cleaning the existing datadir and innodb-data/log directories"
         if [ "${OS}" = "FreeBSD" ]; then
-            find -E $ib_home_dir $ib_log_dir $ib_undo_dir $DATA -mindepth 1 -prune -regex $cpat -o -exec rm -rfv {} 1>&2 \+
+            find -E ${ib_home_dir:+"$ib_home_dir"} \
+                    ${ib_undo_dir:+"$ib_undo_dir"} \
+                    ${ib_log_dir:+"$ib_log_dir"} \
+                    "$DATA" -mindepth 1 -prune -regex "$cpat" -o -exec rm -rfv {} 1>&2 \+
         else
-            find $ib_home_dir $ib_log_dir $ib_undo_dir $DATA -mindepth 1 -prune -regex $cpat -o -exec rm -rfv {} 1>&2 \+
+            find ${ib_home_dir:+"$ib_home_dir"} \
+                 ${ib_undo_dir:+"$ib_undo_dir"} \
+                 ${ib_log_dir:+"$ib_log_dir"} \
+                 "$DATA" -mindepth 1 -prune -regex "$cpat" -o -exec rm -rfv {} 1>&2 \+
         fi
 
-        tempdir=$LOG_BIN_ARG
-        if [ -z "$tempdir" ]; then
-            tempdir=$(parse_cnf mysqld$WSREP_SST_OPT_SUFFIX_VALUE log-bin "")
-        fi
-        if [ -z "$tempdir" ]; then
-            tempdir=$(parse_cnf --mysqld log-bin "")
-        fi
-        if [[ -n ${tempdir:-} ]];then
-            binlog_dir=$(dirname $tempdir)
-            binlog_file=$(basename $tempdir)
-            if [[ -n ${binlog_dir:-} && $binlog_dir != '.' && $binlog_dir != $DATA ]];then
-                pattern="$binlog_dir/$binlog_file\.[0-9]+$"
-                wsrep_log_info "Cleaning the binlog directory $binlog_dir as well"
-                find $binlog_dir -maxdepth 1 -type f -regex $pattern -exec rm -fv {} 1>&2 \+ || true
-                rm $binlog_dir/*.index || true
-            fi
+        get_binlog
+
+        if [ -n "$WSREP_SST_OPT_BINLOG" ]; then
+            binlog_dir=$(dirname "$WSREP_SST_OPT_BINLOG")
+            wsrep_log_info "Cleaning the binlog directory $binlog_dir as well"
+            rm -fv "$WSREP_SST_OPT_BINLOG".[0-9]* 1>&2 \+ || true
+            rm -fv "$WSREP_SST_OPT_BINLOG_INDEX"  1>&2 \+ || true
         fi
 
-        TDATA=${DATA}
-        DATA="${DATA}/.sst"
+        TDATA="$DATA"
+        DATA="$DATA/.sst"
 
-        MAGIC_FILE="${DATA}/${INFO_FILE}"
+        MAGIC_FILE="$DATA/$INFO_FILE"
         wsrep_log_info "Waiting for SST streaming to complete!"
         monitor_process $jpid
 
         get_proc
 
-        if [[ ! -s ${DATA}/xtrabackup_checkpoints ]];then
-            wsrep_log_error "xtrabackup_checkpoints missing, failed innobackupex/SST on donor"
+        if [[ ! -s "$DATA/xtrabackup_checkpoints" ]];then
+            wsrep_log_error "xtrabackup_checkpoints missing, failed mariabackup/SST on donor"
             exit 2
         fi
 
-        # Rebuild indexes for compact backups
-        if grep -q 'compact = 1' ${DATA}/xtrabackup_checkpoints;then
+        # Compact backups are not supported by mariabackup
+        if grep -q 'compact = 1' "$DATA/xtrabackup_checkpoints"; then
             wsrep_log_info "Index compaction detected"
-            rebuild=1
-        fi
-
-        if [[ $rebuild -eq 1 ]];then
-            nthreads=$(parse_cnf xtrabackup rebuild-threads $nproc)
-            wsrep_log_info "Rebuilding during prepare with $nthreads threads"
-            rebuildcmd="--rebuild-indexes --rebuild-threads=$nthreads"
+            wsrel_log_error "Compact backups are not supported by mariabackup"
+            exit 2
         fi
 
-        if test -n "$(find ${DATA} -maxdepth 1 -type f -name '*.qp' -print -quit)";then
-
+        qpfiles=$(find "$DATA" -maxdepth 1 -type f -name '*.qp' -print -quit)
+        if [ -n "$qpfiles" ]; then
             wsrep_log_info "Compressed qpress files found"
 
             if ! command -v qpress >/dev/null;then
@@ -1108,8 +1053,8 @@ then
                 exit 22
             fi
 
-            if [[ -n $progress ]] && pv --help | grep -q 'line-mode';then
-                count=$(find ${DATA} -type f -name '*.qp' | wc -l)
+            if [[ -n "$progress" ]] && pv --help | grep -q 'line-mode';then
+                count=$(find "$DATA" -type f -name '*.qp' | wc -l)
                 count=$(( count*2 ))
                 if pv --help | grep -q FORMAT;then
                     pvopts="-f -s $count -l -N Decompression -F '%N => Rate:%r Elapsed:%t %e Progress: [%b/$count]'"
@@ -1125,12 +1070,12 @@ then
 
             # Decompress the qpress files
             wsrep_log_info "Decompression with $nproc threads"
-            timeit "Joiner-Decompression" "find ${DATA} -type f -name '*.qp' -printf '%p\n%h\n' | $dcmd"
+            timeit "Joiner-Decompression" "find '$DATA' -type f -name '*.qp' -printf '%p\n%h\n' | $dcmd"
             extcode=$?
 
             if [[ $extcode -eq 0 ]];then
                 wsrep_log_info "Removing qpress files after decompression"
-                find ${DATA} -type f -name '*.qp' -delete
+                find "$DATA" -type f -name '*.qp' -delete
                 if [[ $? -ne 0 ]];then
                     wsrep_log_error "Something went wrong with deletion of qpress files. Investigate"
                 fi
@@ -1140,40 +1085,38 @@ then
             fi
         fi
 
-        if  [[ ! -z $WSREP_SST_OPT_BINLOG ]];then
+        if  [ -n "$WSREP_SST_OPT_BINLOG" ]; then
 
-            BINLOG_DIRNAME=$(dirname $WSREP_SST_OPT_BINLOG)
-            BINLOG_FILENAME=$(basename $WSREP_SST_OPT_BINLOG)
+            BINLOG_DIRNAME=$(dirname "$WSREP_SST_OPT_BINLOG")
+            BINLOG_FILENAME=$(basename "$WSREP_SST_OPT_BINLOG")
 
             # To avoid comparing data directory and BINLOG_DIRNAME
-            mv $DATA/${BINLOG_FILENAME}.* $BINLOG_DIRNAME/ 2>/dev/null || true
+            mv "$DATA/$BINLOG_FILENAME".* "$BINLOG_DIRNAME/" 2>/dev/null || true
 
-            pushd $BINLOG_DIRNAME &>/dev/null
-            for bfiles in $(ls -1 ${BINLOG_FILENAME}.[0-9]*);do
-                echo ${BINLOG_DIRNAME}/${bfiles} >> ${BINLOG_FILENAME}.index
+            pushd "$BINLOG_DIRNAME" &>/dev/null
+            for bfile in $(ls -1 "$BINLOG_FILENAME".[0-9]*); do
+                echo "$BINLOG_DIRNAME/$bfile" >> "$WSREP_SST_OPT_BINLOG_INDEX"
             done
             popd &> /dev/null
 
         fi
 
         wsrep_log_info "Preparing the backup at ${DATA}"
+        setup_commands
         timeit "Xtrabackup prepare stage" "$INNOAPPLY"
 
-        if [ $? -ne 0 ];
-        then
-            wsrep_log_error "${INNOBACKUPEX_BIN} apply finished with errors. Check syslog or ${INNOAPPLYLOG} for details"
+        if [ $? -ne 0 ]; then
+            wsrep_log_error "${MARIABACKUP_BIN} apply finished with errors. Check syslog or ${INNOAPPLYLOG} for details"
             exit 22
         fi
 
-        MAGIC_FILE="${TDATA}/${INFO_FILE}"
-        set +e
-        set -e
+        MAGIC_FILE="$TDATA/$INFO_FILE"
         wsrep_log_info "Moving the backup to ${TDATA}"
         timeit "Xtrabackup move stage" "$INNOMOVE"
         if [[ $? -eq 0 ]];then
             wsrep_log_info "Move successful, removing ${DATA}"
-            rm -rf $DATA
-            DATA=${TDATA}
+            rm -rf "$DATA"
+            DATA="$TDATA"
         else
             wsrep_log_error "Move failed, keeping ${DATA} for further diagnosis"
             wsrep_log_error "Check syslog or ${INNOMOVELOG} for details"
@@ -1186,11 +1129,11 @@ then
 
     fi
 
-    if [[ ! -r ${MAGIC_FILE} ]];then
+    if [ ! -r "$MAGIC_FILE" ]; then
         wsrep_log_error "SST magic file ${MAGIC_FILE} not found/readable"
         exit 2
     fi
-    wsrep_log_info "Galera co-ords from recovery: $(cat ${MAGIC_FILE})"
+    wsrep_log_info "Galera co-ords from recovery: $(cat '${MAGIC_FILE}')"
     cat "${MAGIC_FILE}" # Output : UUID:seqno wsrep_gtid_domain_id
 
     wsrep_log_info "Total time on joiner: $totime seconds"
diff --git a/scripts/wsrep_sst_mysqldump.sh b/scripts/wsrep_sst_mysqldump.sh
index 664fd2c04f9..ba59db66a73 100644
--- a/scripts/wsrep_sst_mysqldump.sh
+++ b/scripts/wsrep_sst_mysqldump.sh
@@ -60,7 +60,7 @@ then
     exit $EINVAL
 fi
 
-[ -n "$WSREP_SST_OPT_USER" ] && AUTH="-u$WSREP_SST_OPT_USER" || AUTH=
+[ -n "$WSREP_SST_OPT_USER" -a "$WSREP_SST_OPT_USER" != '(null)' ] && AUTH="-u$WSREP_SST_OPT_USER" || AUTH=
 
 # Refs https://github.com/codership/mysql-wsrep/issues/141
 # Passing password in MYSQL_PWD environment variable is considered
diff --git a/scripts/wsrep_sst_rsync.sh b/scripts/wsrep_sst_rsync.sh
index 6662fe35224..d42d73cb35c 100644
--- a/scripts/wsrep_sst_rsync.sh
+++ b/scripts/wsrep_sst_rsync.sh
@@ -29,6 +29,7 @@ OS=$(uname)
 export PATH="/usr/sbin:/sbin:$PATH"
 
 . $(dirname $0)/wsrep_sst_common
+wsrep_check_datadir
 
 wsrep_check_programs rsync
 
@@ -54,13 +55,13 @@ cleanup_joiner()
 # Check whether rsync process is still running.
 check_pid()
 {
-    local pid_file=$1
-    [ -r "$pid_file" ] && ps -p $(cat $pid_file) >/dev/null 2>&1
+    local pid_file="$1"
+    [ -r "$pid_file" ] && ps -p $(cat "$pid_file") >/dev/null 2>&1
 }
 
 check_pid_and_port()
 {
-    local pid_file=$1
+    local pid_file="$1"
     local rsync_pid=$2
     local rsync_addr=$3
     local rsync_port=$4
@@ -73,7 +74,7 @@ check_pid_and_port()
             grep -E '[[:space:]]+(rsync|stunnel)[[:space:]]+'"$rsync_pid" 2>/dev/null)"
         ;;
     *)
-        if ! which lsof > /dev/null; then
+        if ! [ -x $(command -v "lsof") ]; then
           wsrep_log_error "lsof tool not found in PATH! Make sure you have it installed."
           exit 2 # ENOENT
         fi
@@ -96,22 +97,21 @@ check_pid_and_port()
             exit 16 # EBUSY
         fi
     fi
-    check_pid $pid_file && \
+    check_pid "$pid_file" && \
         [ -n "$port_info" ] && [ -n "$is_rsync" ] && \
-        [ $(cat $pid_file) -eq $rsync_pid ]
+        [ $(cat "$pid_file") -eq $rsync_pid ]
 }
 
 is_local_ip()
 {
   local address="$1"
-  local get_addr_bin=`which ifconfig`
+  local get_addr_bin="$(command -v ifconfig)"
   if [ -z "$get_addr_bin" ]
   then
-    get_addr_bin=`which ip`
-    get_addr_bin="$get_addr_bin address show"
+    get_addr_bin="$(command -v ip) address show"
     # Add an slash at the end, so we don't get false positive : 172.18.0.4 matches 172.18.0.41
     # ip output format is "X.X.X.X/mask"
-    address="${address}/"
+    address="$address/"
   else
     # Add an space at the end, so we don't get false positive : 172.18.0.4 matches 172.18.0.41
     # ifconfig output format is "X.X.X.X "
@@ -134,62 +134,46 @@ BINLOG_TAR_FILE="$WSREP_SST_OPT_DATA/wsrep_sst_binlog.tar"
 BINLOG_N_FILES=1
 rm -f "$BINLOG_TAR_FILE" || :
 
-if ! [ -z $WSREP_SST_OPT_BINLOG ]
-then
-    BINLOG_DIRNAME=$(dirname $WSREP_SST_OPT_BINLOG)
-    BINLOG_FILENAME=$(basename $WSREP_SST_OPT_BINLOG)
-    BINLOG_INDEX_DIRNAME=$(dirname $WSREP_SST_OPT_BINLOG)
-    BINLOG_INDEX_FILENAME=$(basename $WSREP_SST_OPT_BINLOG)
-fi
+get_binlog
 
-if ! [ -z $WSREP_SST_OPT_BINLOG_INDEX ]
-then
-    BINLOG_INDEX_DIRNAME=$(dirname $WSREP_SST_OPT_BINLOG_INDEX)
-    BINLOG_INDEX_FILENAME=$(basename $WSREP_SST_OPT_BINLOG_INDEX)
+if [ -n "$WSREP_SST_OPT_BINLOG" ]; then
+    BINLOG_DIRNAME=$(dirname "$WSREP_SST_OPT_BINLOG")
+    BINLOG_FILENAME=$(basename "$WSREP_SST_OPT_BINLOG")
 fi
 
-WSREP_LOG_DIR=${WSREP_LOG_DIR:-""}
-# Try to set WSREP_LOG_DIR from the command line:
-if [ ! -z "$INNODB_LOG_GROUP_HOME_ARG" ]; then
-    WSREP_LOG_DIR=$INNODB_LOG_GROUP_HOME_ARG
+if [ -n "$WSREP_SST_OPT_BINLOG_INDEX" ]; then
+    BINLOG_INDEX_DIRNAME=$(dirname "$WSREP_SST_OPT_BINLOG_INDEX")
+    BINLOG_INDEX_FILENAME=$(basename "$WSREP_SST_OPT_BINLOG_INDEX")
 fi
-# if no command line arg and WSREP_LOG_DIR is not set,
+
+# if no command line argument and INNODB_LOG_GROUP_HOME is not set,
 # try to get it from my.cnf:
-if [ -z "$WSREP_LOG_DIR" ]; then
-    WSREP_LOG_DIR=$(parse_cnf mysqld$WSREP_SST_OPT_SUFFIX_VALUE innodb-log-group-home-dir '')
-fi
-if [ -z "$WSREP_LOG_DIR" ]; then
-    WSREP_LOG_DIR=$(parse_cnf --mysqld innodb-log-group-home-dir '')
+if [ -z "$INNODB_LOG_GROUP_HOME" ]; then
+    INNODB_LOG_GROUP_HOME=$(parse_cnf --mysqld innodb-log-group-home-dir)
 fi
 
+WSREP_LOG_DIR="$INNODB_LOG_GROUP_HOME"
+
 if [ -n "$WSREP_LOG_DIR" ]; then
     # handle both relative and absolute paths
-    WSREP_LOG_DIR=$(cd $WSREP_SST_OPT_DATA; mkdir -p "$WSREP_LOG_DIR"; cd $WSREP_LOG_DIR; pwd -P)
+    WSREP_LOG_DIR=$(cd "$WSREP_SST_OPT_DATA"; mkdir -p "$WSREP_LOG_DIR"; cd "$WSREP_LOG_DIR"; pwd -P)
 else
     # default to datadir
-    WSREP_LOG_DIR=$(cd $WSREP_SST_OPT_DATA; pwd -P)
+    WSREP_LOG_DIR=$(cd "$WSREP_SST_OPT_DATA"; pwd -P)
 fi
 
-INNODB_DATA_HOME_DIR=${INNODB_DATA_HOME_DIR:-""}
-# Try to set INNODB_DATA_HOME_DIR from the command line:
-if [ ! -z "$INNODB_DATA_HOME_DIR_ARG" ]; then
-    INNODB_DATA_HOME_DIR=$INNODB_DATA_HOME_DIR_ARG
-fi
 # if no command line arg and INNODB_DATA_HOME_DIR environment variable
 # is not set, try to get it from my.cnf:
 if [ -z "$INNODB_DATA_HOME_DIR" ]; then
-    INNODB_DATA_HOME_DIR=$(parse_cnf mysqld$WSREP_SST_OPT_SUFFIX_VALUE innodb-data-home-dir '')
-fi
-if [ -z "$INNODB_DATA_HOME_DIR" ]; then
-    INNODB_DATA_HOME_DIR=$(parse_cnf --mysqld innodb-data-home-dir '')
+    INNODB_DATA_HOME_DIR=$(parse_cnf --mysqld innodb-data-home-dir)
 fi
 
 if [ -n "$INNODB_DATA_HOME_DIR" ]; then
     # handle both relative and absolute paths
-    INNODB_DATA_HOME_DIR=$(cd $WSREP_SST_OPT_DATA; mkdir -p "$INNODB_DATA_HOME_DIR"; cd $INNODB_DATA_HOME_DIR; pwd -P)
+    INNODB_DATA_HOME_DIR=$(cd "$WSREP_SST_OPT_DATA"; mkdir -p "$INNODB_DATA_HOME_DIR"; cd "$INNODB_DATA_HOME_DIR"; pwd -P)
 else
     # default to datadir
-    INNODB_DATA_HOME_DIR=$(cd $WSREP_SST_OPT_DATA; pwd -P)
+    INNODB_DATA_HOME_DIR=$(cd "$WSREP_SST_OPT_DATA"; pwd -P)
 fi
 
 # Old filter - include everything except selected
@@ -242,7 +226,7 @@ EOF
         rm -rf "$ERROR"
 
         # Use deltaxfer only for WAN
-        inv=$(basename $0)
+        inv=$(basename "$0")
         [ "$inv" = "wsrep_sst_rsync_wan" ] && WHOLE_FILE_OPT="" \
                                            || WHOLE_FILE_OPT="--whole-file"
 
@@ -266,35 +250,31 @@ EOF
             sleep 0.2
         done
 
-        STATE="$(cat $FLUSHED)"
+        STATE=$(cat "$FLUSHED")
         rm -rf "$FLUSHED"
 
         sync
 
-        if ! [ -z $WSREP_SST_OPT_BINLOG ]
+        if [ -n "$WSREP_SST_OPT_BINLOG" ]
         then
             # Prepare binlog files
             OLD_PWD="$(pwd)"
-            cd $BINLOG_DIRNAME
 
-            if ! [ -z $WSREP_SST_OPT_BINLOG_INDEX ]
-               binlog_files_full=$(tail -n $BINLOG_N_FILES ${BINLOG_FILENAME}.index)
-            then
-               cd $BINLOG_INDEX_DIRNAME
-               binlog_files_full=$(tail -n $BINLOG_N_FILES ${BINLOG_INDEX_FILENAME}.index)
-            fi
+            cd "$BINLOG_INDEX_DIRNAME"
+            binlog_files_full=$(tail -n $BINLOG_N_FILES "$BINLOG_INDEX_FILENAME")
 
-            cd $BINLOG_DIRNAME
             binlog_files=""
             for ii in $binlog_files_full
             do
-                binlog_files="$binlog_files $(basename $ii)"
+                binlog_file=$(basename "$ii")
+                binlog_files="$binlog_files $binlog_file"
             done
 
-            if ! [ -z "$binlog_files" ]
+            cd "$BINLOG_DIRNAME"
+            if [ -n "$binlog_files" ]
             then
                 wsrep_log_info "Preparing binlog files for transfer:"
-                tar -cvf $BINLOG_TAR_FILE $binlog_files >&2
+                tar -cvf "$BINLOG_TAR_FILE" $binlog_files >&2
             fi
             cd "$OLD_PWD"
         fi
@@ -307,7 +287,7 @@ EOF
               $WHOLE_FILE_OPT ${FILTER} "$WSREP_SST_OPT_DATA/" \
               rsync://$WSREP_SST_OPT_ADDR >&2 || RC=$?
 
-        if [ "$RC" -ne 0 ]; then
+        if [ $RC -ne 0 ]; then
             wsrep_log_error "rsync returned code $RC:"
 
             case $RC in
@@ -351,7 +331,7 @@ EOF
 
         # then, we parallelize the transfer of database directories, use . so that pathconcatenation works
         OLD_PWD="$(pwd)"
-        cd $WSREP_SST_OPT_DATA
+        cd "$WSREP_SST_OPT_DATA"
 
         count=1
         [ "$OS" = "Linux" ] && count=$(grep -c processor /proc/cpuinfo)
@@ -394,41 +374,31 @@ elif [ "$WSREP_SST_OPT_ROLE" = "joiner" ]
 then
     wsrep_check_programs lsof
 
-    touch $SST_PROGRESS_FILE
-    MYSQLD_PID=$WSREP_SST_OPT_PARENT
+    touch "$SST_PROGRESS_FILE"
+    MYSQLD_PID="$WSREP_SST_OPT_PARENT"
 
     MODULE="rsync_sst"
 
     RSYNC_PID="$WSREP_SST_OPT_DATA/$MODULE.pid"
     # give some time for lingering rsync from previous SST to complete
     check_round=0
-    while check_pid $RSYNC_PID && [ $check_round -lt 10 ]
+    while check_pid "$RSYNC_PID" && [ $check_round -lt 10 ]
     do
         wsrep_log_info "lingering rsync daemon found at startup, waiting for it to exit"
         check_round=$(( check_round + 1 ))
         sleep 1
     done
 
-    if check_pid $RSYNC_PID
+    if check_pid "$RSYNC_PID"
     then
         wsrep_log_error "rsync daemon already running."
         exit 114 # EALREADY
     fi
     rm -rf "$RSYNC_PID"
 
-    ADDR=$WSREP_SST_OPT_ADDR
-    if [ "${ADDR#\[}" != "$ADDR" ]; then
-        RSYNC_PORT=$(echo $ADDR | awk -F '\\]:' '{ print $2 }')
-        RSYNC_ADDR=$(echo $ADDR | awk -F '\\]:' '{ print $1 }')"]"
-    else
-        RSYNC_PORT=$(echo $ADDR | awk -F ':' '{ print $2 }')
-        RSYNC_ADDR=$(echo $ADDR | awk -F ':' '{ print $1 }')
-    fi
-    if [ -z "$RSYNC_PORT" ]
-    then
-        RSYNC_PORT=4444
-        ADDR="$RSYNC_ADDR:$RSYNC_PORT"
-    fi
+    ADDR="$WSREP_SST_OPT_ADDR"
+    RSYNC_PORT="$WSREP_SST_OPT_PORT"
+    RSYNC_ADDR="$WSREP_SST_OPT_HOST"
 
     trap "exit 32" HUP PIPE
     trap "exit 3"  INT TERM ABRT
@@ -436,7 +406,7 @@ then
 
     RSYNC_CONF="$WSREP_SST_OPT_DATA/$MODULE.conf"
 
-    if [ -n "${MYSQL_TMP_DIR:-}" ] ; then
+    if [ -n "${MYSQL_TMP_DIR:-}" ]; then
         SILENT="log file = $MYSQL_TMP_DIR/rsyncd.log"
     else
         SILENT=""
@@ -459,7 +429,6 @@ EOF
 
 #    rm -rf "$DATA"/ib_logfile* # we don't want old logs around
 
-    readonly RSYNC_PORT=${WSREP_SST_OPT_PORT:-4444}
     # If the IP is local listen only in it
     if is_local_ip "$RSYNC_ADDR"
     then
@@ -487,12 +456,12 @@ debug = warning
 client = no
 [rsync]
 accept = $STUNNEL_ACCEPT
-exec = $(which rsync)
-execargs = rsync --server --daemon --config=$RSYNC_CONF .
+exec = $(command -v rsync)
+execargs = rsync --server --daemon --config='$RSYNC_CONF' .
 EOF
       stunnel "$STUNNEL_CONF" &
       RSYNC_REAL_PID=$!
-      RSYNC_PID=$STUNNEL_PID
+      RSYNC_PID="$STUNNEL_PID"
     fi
 
     until check_pid_and_port "$RSYNC_PID" "$RSYNC_REAL_PID" "$RSYNC_ADDR" "$RSYNC_PORT"
@@ -513,35 +482,31 @@ EOF
     then
         wsrep_log_error \
         "Parent mysqld process (PID:$MYSQLD_PID) terminated unexpectedly."
-        kill -- -"${MYSQLD_PID}"
+        kill -- -$MYSQLD_PID
         sleep 1
         exit 32
     fi
 
-    if ! [ -z $WSREP_SST_OPT_BINLOG ]
-    then
+    if [ -n "$WSREP_SST_OPT_BINLOG" ]; then
 
         OLD_PWD="$(pwd)"
-        cd $BINLOG_DIRNAME
+        cd "$BINLOG_DIRNAME"
 
-        if [ -f $BINLOG_TAR_FILE ]
-        then
+        if [ -f "$BINLOG_TAR_FILE" ]; then
             # Clean up old binlog files first
-            rm -f ${BINLOG_FILENAME}.*
+            rm -f "$BINLOG_FILENAME".*
             wsrep_log_info "Extracting binlog files:"
-            tar -xvf $BINLOG_TAR_FILE >&2
-            for ii in $(ls -1 ${BINLOG_FILENAME}.*)
-            do
-                if ! [ -z $WSREP_SST_OPT_BINLOG_INDEX ]
-                  echo ${BINLOG_DIRNAME}/${ii} >> ${BINLOG_FILENAME}.index
-                then
-                  echo ${BINLOG_DIRNAME}/${ii} >> ${BINLOG_INDEX_DIRNAME}/${BINLOG_INDEX_FILENAME}.index
-                fi
-            done
+            tar -xvf "$BINLOG_TAR_FILE" >> _binlog_tmp_files_$!
+            while read bin_file; do
+                echo "$BINLOG_DIRNAME/$bin_file" >> "$BINLOG_INDEX_DIRNAME/$BINLOG_INDEX_FILENAME"
+            done < _binlog_tmp_files_$!
+            rm -f _binlog_tmp_files_$!
         fi
+
         cd "$OLD_PWD"
 
     fi
+
     if [ -r "$MAGIC_FILE" ]
     then
         # UUID:seqno & wsrep_gtid_domain_id is received here.
@@ -557,6 +522,6 @@ else
     exit 22 # EINVAL
 fi
 
-rm -f $BINLOG_TAR_FILE || :
+rm -f "$BINLOG_TAR_FILE" || :
 
 exit 0
diff --git a/scripts/wsrep_sst_xtrabackup-v2.sh b/scripts/wsrep_sst_xtrabackup-v2.sh
index a47f7799d3b..1a1b7590458 100644
--- a/scripts/wsrep_sst_xtrabackup-v2.sh
+++ b/scripts/wsrep_sst_xtrabackup-v2.sh
@@ -19,6 +19,7 @@
 # Make sure to read that before proceeding!
 
 . $(dirname $0)/wsrep_sst_common
+wsrep_check_datadir
 
 ealgo=""
 ekey=""
@@ -93,7 +94,7 @@ if ! which lsof > /dev/null; then
 fi
 
 timeit(){
-    local stage=$1
+    local stage="$1"
     shift
     local cmd="$@"
     local x1 x2 took extcode
@@ -137,17 +138,17 @@ get_keys()
 
     wsrep_log_info "Xtrabackup based encryption enabled in my.cnf - Supported only from Xtrabackup 2.1.4"
 
-    if [[ -z $ealgo ]];then
+    if [[ -z "$ealgo" ]];then
         wsrep_log_error "FATAL: Encryption algorithm empty from my.cnf, bailing out"
         exit 3
     fi
 
-    if [[ -z $ekey && ! -r $ekeyfile ]];then
+    if [[ -z "$ekey" && ! -r "$ekeyfile" ]];then
         wsrep_log_error "FATAL: Either key or keyfile must be readable"
         exit 3
     fi
 
-    if [[ -z $ekey ]];then
+    if [[ -z "$ekey" ]];then
         ecmd="xbcrypt --encrypt-algo=$ealgo --encrypt-key-file=$ekeyfile"
     else
         wsrep_log_warning "Using the 'encrypt-key' option causes the encryption key"
@@ -199,8 +200,8 @@ check_for_dhparams()
 #
 verify_cert_matches_key()
 {
-    local cert_path=$1
-    local key_path=$2
+    local cert_path="$1"
+    local key_path="$2"
 
     wsrep_check_programs openssl diff
 
@@ -226,9 +227,9 @@ verify_cert_matches_key()
 #
 verify_file_exists()
 {
-    local file_path=$1
-    local error_message1=$2
-    local error_message2=$3
+    local file_path="$1"
+    local error_message1="$2"
+    local error_message2="$3"
 
     if ! [[ -r "$file_path" ]]; then
         wsrep_log_error "******** FATAL ERROR ************************* "
@@ -246,7 +247,7 @@ verify_file_exists()
 
 get_transfer()
 {
-    TSST_PORT=${WSREP_SST_OPT_PORT:-4444}
+    TSST_PORT="$WSREP_SST_OPT_PORT"
 
     if [[ $tfmt == 'nc' ]];then
         if [[ ! -x `which nc` ]];then
@@ -264,26 +265,46 @@ get_transfer()
 
         wsrep_log_info "Using netcat as streamer"
         if [[ "$WSREP_SST_OPT_ROLE"  == "joiner" ]];then
-            if nc -h 2>&1 | grep -q ncat; then
+            if nc -h 2>&1 | grep -q ncat;then
                 # Ncat
-                tcmd="nc $sockopt -l ${TSST_PORT}"
-            elif nc -h 2>&1 | grep -q -- '-d\>';then
+                tcmd="nc -l ${TSST_PORT}"
+            elif nc -h 2>&1 | grep -qw -- '-d\>';then
                 # Debian netcat
-                tcmd="nc $sockopt -dl ${TSST_PORT}"
+                if [ $WSREP_SST_OPT_HOST_IPv6 -eq 1 ];then
+                    # When host is not explicitly specified (when only the port
+                    # is specified) netcat can only bind to an IPv4 address if
+                    # the "-6" option is not explicitly specified:
+                    tcmd="nc -dl -6 ${TSST_PORT}"
+                else
+                    tcmd="nc -dl ${TSST_PORT}"
+                fi
             else
                 # traditional netcat
-                tcmd="nc $sockopt -l -p ${TSST_PORT}"
+                tcmd="nc -l -p ${TSST_PORT}"
             fi
         else
+            # Check to see if netcat supports the '-N' flag.
+            # -N Shutdown the network socket after EOF on stdin
+            # If it supports the '-N' flag, then we need to use the '-N'
+            # flag, otherwise the transfer will stay open after the file
+            # transfer and cause the command to timeout.
+            # Older versions of netcat did not need this flag and will
+            # return an error if the flag is used.
+            #
+            tcmd_extra=""
+            if nc -h 2>&1 | grep -qw -- -N;then
+                tcmd_extra+="-N"
+            fi
+            # netcat doesn't understand [] around IPv6 address
             if nc -h 2>&1 | grep -q ncat;then
                 # Ncat
-                tcmd="nc ${WSREP_SST_OPT_HOST_UNESCAPED} ${TSST_PORT}"
-            elif nc -h 2>&1 | grep -q -- '-d\>';then
+                tcmd="nc ${tcmd_extra} ${WSREP_SST_OPT_HOST_UNESCAPED} ${TSST_PORT}"
+            elif nc -h 2>&1 | grep -qw -- '-d\>';then
                 # Debian netcat
-                tcmd="nc ${WSREP_SST_OPT_HOST_UNESCAPED} ${TSST_PORT}"
+                tcmd="nc ${tcmd_extra} ${WSREP_SST_OPT_HOST_UNESCAPED} ${TSST_PORT}"
             else
                 # traditional netcat
-                tcmd="nc -q0 ${WSREP_SST_OPT_HOST_UNESCAPED} ${TSST_PORT}"
+                tcmd="nc -q0 ${tcmd_extra} ${WSREP_SST_OPT_HOST_UNESCAPED} ${TSST_PORT}"
             fi
         fi
     else
@@ -323,7 +344,7 @@ get_transfer()
                 if [[ "$WSREP_SST_OPT_ROLE"  == "joiner" ]]; then
                     # dhparams check (will create ssl_dhparams if needed)
                     check_for_dhparams
-                    joiner_extra=",dhparam=$ssl_dhparams"
+                    joiner_extra=",dhparam='$ssl_dhparams'"
                 fi
             fi
             if check_for_version "$SOCAT_VERSION" "1.7.3"; then
@@ -343,10 +364,10 @@ get_transfer()
             stagemsg+="-OpenSSL-Encrypted-2"
             if [[ "$WSREP_SST_OPT_ROLE"  == "joiner" ]];then
                 wsrep_log_info "Decrypting with CERT: $tcert, CA: $tca"
-                tcmd="socat -u openssl-listen:${TSST_PORT},reuseaddr,cert=${tcert},cafile=${tca}${joiner_extra}${sockopt} stdio"
+                tcmd="socat -u openssl-listen:${TSST_PORT},reuseaddr,cert='${tcert}',cafile='${tca}'${joiner_extra}${sockopt} stdio"
             else
                 wsrep_log_info "Encrypting with CERT: $tcert, CA: $tca"
-                tcmd="socat -u stdio openssl-connect:${WSREP_SST_OPT_HOST}:${TSST_PORT},cert=${tcert},cafile=${tca}${donor_extra}${sockopt}"
+                tcmd="socat -u stdio openssl-connect:${WSREP_SST_OPT_HOST}:${TSST_PORT},cert='${tcert}',cafile='${tca}'${donor_extra}${sockopt}"
             fi
         elif [[ $encrypt -eq 3 ]];then
             wsrep_log_warning "**** WARNING **** encrypt=3 is deprecated and will be removed in a future release"
@@ -360,10 +381,10 @@ get_transfer()
             stagemsg+="-OpenSSL-Encrypted-3"
             if [[ "$WSREP_SST_OPT_ROLE"  == "joiner" ]];then
                 wsrep_log_info "Decrypting with CERT: $tcert, KEY: $tkey"
-                tcmd="socat -u openssl-listen:${TSST_PORT},reuseaddr,cert=${tcert},key=${tkey},verify=0${joiner_extra}${sockopt} stdio"
+                tcmd="socat -u openssl-listen:${TSST_PORT},reuseaddr,cert='${tcert}',key='${tkey}',verify=0${joiner_extra}${sockopt} stdio"
             else
                 wsrep_log_info "Encrypting with CERT: $tcert, KEY: $tkey"
-                tcmd="socat -u stdio openssl-connect:${WSREP_SST_OPT_HOST}:${TSST_PORT},cert=${tcert},key=${tkey},verify=0${sockopt}"
+                tcmd="socat -u stdio openssl-connect:${WSREP_SST_OPT_HOST}:${TSST_PORT},cert='${tcert}',key='${tkey}',verify=0${sockopt}"
             fi
         elif [[ $encrypt -eq 4 ]]; then
             wsrep_log_info "Using openssl based encryption with socat: with key, crt, and ca"
@@ -381,10 +402,10 @@ get_transfer()
             stagemsg+="-OpenSSL-Encrypted-4"
             if [[ "$WSREP_SST_OPT_ROLE"  == "joiner" ]]; then
                 wsrep_log_info "Decrypting with CERT: $ssl_cert, KEY: $ssl_key, CA: $ssl_ca"
-                tcmd="socat -u openssl-listen:${TSST_PORT},reuseaddr,cert=${ssl_cert},key=${ssl_key},cafile=${ssl_ca},verify=1${joiner_extra}${sockopt} stdio"
+                tcmd="socat -u openssl-listen:${TSST_PORT},reuseaddr,cert='${ssl_cert}',key='${ssl_key}',cafile='${ssl_ca}',verify=1${joiner_extra}${sockopt} stdio"
             else
                 wsrep_log_info "Encrypting with CERT: $ssl_cert, KEY: $ssl_key, CA: $ssl_ca"
-                tcmd="socat -u stdio openssl-connect:${WSREP_SST_OPT_HOST}:${TSST_PORT},cert=${ssl_cert},key=${ssl_key},cafile=${ssl_ca},verify=1${donor_extra}${sockopt}"
+                tcmd="socat -u stdio openssl-connect:${WSREP_SST_OPT_HOST}:${TSST_PORT},cert='${ssl_cert}',key='${ssl_key}',cafile='${ssl_ca}',verify=1${donor_extra}${sockopt}"
             fi
 
         else
@@ -403,7 +424,7 @@ get_transfer()
 
 get_footprint()
 {
-    pushd $WSREP_SST_OPT_DATA 1>/dev/null
+    pushd "$WSREP_SST_OPT_DATA" 1>/dev/null
     payload=$(find . -regex '.*\.ibd$\|.*\.MYI$\|.*\.MYD$\|.*ibdata1$' -type f -print0 | du --files0-from=- --block-size=1 -c -s | awk 'END { print $1 }')
     if $MY_PRINT_DEFAULTS xtrabackup | grep -q -- "--compress";then
         # QuickLZ has around 50% compression ratio
@@ -426,18 +447,18 @@ adjust_progress()
         return
     fi
 
-    if [[ -n $progress && $progress != '1' ]];then
-        if [[ -e $progress ]];then
+    if [[ -n "$progress" && "$progress" != '1' ]];then
+        if [[ -e "$progress" ]];then
             pcmd+=" 2>>$progress"
         else
             pcmd+=" 2>$progress"
         fi
-    elif [[ -z $progress && -n $rlimit  ]];then
+    elif [[ -z "$progress" && -n "$rlimit" ]];then
             # When rlimit is non-zero
             pcmd="pv -q"
     fi
 
-    if [[ -n $rlimit && "$WSREP_SST_OPT_ROLE"  == "donor" ]];then
+    if [[ -n "$rlimit" && "$WSREP_SST_OPT_ROLE" == "donor" ]];then
         wsrep_log_info "Rate-limiting SST to $rlimit"
         pcmd+=" -L \$rlimit"
     fi
@@ -467,7 +488,7 @@ read_cnf()
     sdecomp=$(parse_cnf sst decompressor "")
 
     # Refer to http://www.percona.com/doc/percona-xtradb-cluster/manual/xtrabackup_sst.html
-    if [[ -z $ealgo ]];then
+    if [[ -z "$ealgo" ]];then
         ealgo=$(parse_cnf sst encrypt-algo "")
         ekey=$(parse_cnf sst encrypt-key "")
         ekeyfile=$(parse_cnf sst encrypt-key-file "")
@@ -511,15 +532,15 @@ get_stream()
         if [[ "$WSREP_SST_OPT_ROLE"  == "joiner" ]];then
             strmcmd="xbstream -x"
         else
-            strmcmd="xbstream -c \${INFO_FILE}"
+            strmcmd="xbstream -c '${INFO_FILE}'"
         fi
     else
         sfmt="tar"
         wsrep_log_info "Streaming with tar"
         if [[ "$WSREP_SST_OPT_ROLE"  == "joiner" ]];then
-            strmcmd="tar xfi - "
+            strmcmd="tar xfi -"
         else
-            strmcmd="tar cf - \${INFO_FILE} "
+            strmcmd="tar cf - '${INFO_FILE}'"
         fi
     fi
 }
@@ -548,13 +569,12 @@ cleanup_joiner()
         wsrep_log_info "Removing the sst_in_progress file"
         wsrep_cleanup_progress_file
     fi
-    if [[ -n $progress && -p $progress ]];then
+    if [[ -n "$progress" && -p "$progress" ]];then
         wsrep_log_info "Cleaning up fifo file $progress"
         rm $progress
     fi
-
-    if [[ -n ${STATDIR:-} ]];then
-       [[ -d $STATDIR ]] && rm -rf $STATDIR
+    if [[ -n "${STATDIR:-}" ]];then
+       [[ -d "$STATDIR" ]] && rm -rf "$STATDIR"
     fi
 
     # Final cleanup
@@ -587,8 +607,8 @@ cleanup_donor()
         wsrep_log_error "Cleanup after exit with status:$estatus"
     fi
 
-    if [[ -n ${XTRABACKUP_PID:-} ]];then
-        if check_pid $XTRABACKUP_PID
+    if [[ -n "${XTRABACKUP_PID:-}" ]];then
+        if check_pid "$XTRABACKUP_PID"
         then
             wsrep_log_error "xtrabackup process is still running. Killing... "
             kill_xtrabackup
@@ -596,21 +616,21 @@ cleanup_donor()
 
     fi
 
-    rm -f ${DATA}/${IST_FILE} || true
+    rm -f "${DATA}/${IST_FILE}" || true
 
-    if [[ -n $progress && -p $progress ]];then
+    if [[ -n "$progress" && -p "$progress" ]];then
         wsrep_log_info "Cleaning up fifo file $progress"
-        rm -f $progress || true
+        rm -f "$progress" || true
     fi
 
     wsrep_log_info "Cleaning up temporary directories"
 
-    if [[ -n $xtmpdir ]];then
-       [[ -d $xtmpdir ]] &&  rm -rf $xtmpdir || true
+    if [[ -n "$xtmpdir" ]];then
+       [[ -d "$xtmpdir" ]] &&  rm -rf "$xtmpdir" || true
     fi
 
-    if [[ -n $itmpdir ]];then
-       [[ -d $itmpdir ]] &&  rm -rf $itmpdir || true
+    if [[ -n "$itmpdir" ]];then
+       [[ -d "$itmpdir" ]] &&  rm -rf "$itmpdir" || true
     fi
 
     # Final cleanup
@@ -633,7 +653,7 @@ cleanup_donor()
 
 kill_xtrabackup()
 {
-    local PID=$(cat $XTRABACKUP_PID)
+    local PID=$(cat "$XTRABACKUP_PID")
     [ -n "$PID" -a "0" != "$PID" ] && kill $PID && (kill $PID && kill -9 $PID) || :
     wsrep_log_info "Removing xtrabackup pid file $XTRABACKUP_PID"
     rm -f "$XTRABACKUP_PID" || true
@@ -643,9 +663,9 @@ kill_xtrabackup()
 # (regardless of timeout)
 wait_for_listen()
 {
-    local HOST=$1
-    local PORT=$2
-    local MODULE=$3
+    local HOST="$1"
+    local PORT="$2"
+    local MODULE="$3"
     local LSOF_OUT
 
     for i in {1..300}
@@ -664,7 +684,7 @@ check_extra()
     if [[ $uextra -eq 1 ]];then
         if [ $(parse_cnf --mysqld thread-handling) = 'pool-of-threads'];then
             local eport=$(parse_cnf --mysqld extra-port)
-            if [[ -n $eport ]];then
+            if [[ -n "$eport" ]];then
                 # Xtrabackup works only locally.
                 # Hence, setting host to 127.0.0.1 unconditionally.
                 wsrep_log_info "SST through extra_port $eport"
@@ -678,25 +698,25 @@ check_extra()
             wsrep_log_info "Thread pool not set, ignore the option use_extra"
         fi
     fi
-    if [[ $use_socket -eq 1 ]] && [[ -n "$WSREP_SST_OPT_SOCKET" ]];then
-        INNOEXTRA+=" --socket=$WSREP_SST_OPT_SOCKET"
+    if [ $use_socket -eq 1 -a -n "$WSREP_SST_OPT_SOCKET" ]; then
+        INNOEXTRA+=" --socket='$WSREP_SST_OPT_SOCKET'"
     fi
 }
 
 recv_joiner()
 {
-    local dir=$1
-    local msg=$2
+    local dir="$1"
+    local msg="$2"
     local tmt=$3
     local checkf=$4
     local ltcmd
 
-    if [[ ! -d ${dir} ]];then
+    if [[ ! -d "${dir}" ]];then
         # This indicates that IST is in progress
         return
     fi
 
-    pushd ${dir} 1>/dev/null
+    pushd "${dir}" 1>/dev/null
     set +e
 
     if [[ $tmt -gt 0 && -x `which timeout` ]];then
@@ -737,10 +757,10 @@ recv_joiner()
 
 send_donor()
 {
-    local dir=$1
-    local msg=$2
+    local dir="$1"
+    local msg="$2"
 
-    pushd ${dir} 1>/dev/null
+    pushd "${dir}" 1>/dev/null
     set +e
     timeit "$msg" "$strmcmd | $tcmd; RC=( "\${PIPESTATUS[@]}" )"
     set -e
@@ -823,7 +843,7 @@ fi
 XB_REQUIRED_VERSION="2.3.5"
 
 XB_VERSION=`$INNOBACKUPEX_BIN --version 2>&1 | grep -oe '[0-9]\.[0-9][\.0-9]*' | head -n1`
-if [[ -z $XB_VERSION ]]; then
+if [[ -z "$XB_VERSION" ]]; then
     wsrep_log_error "FATAL: Cannot determine the $INNOBACKUPEX_BIN version. Needs xtrabackup-$XB_REQUIRED_VERSION or higher to perform SST"
     exit 2
 fi
@@ -843,18 +863,17 @@ fi
 read_cnf
 
 if ${INNOBACKUPEX_BIN} /tmp --help 2>/dev/null | grep -q -- '--version-check'; then
-    disver="--no-version-check"
+    disver='--no-version-check'
 fi
 
-if [[ ${FORCE_FTWRL:-0} -eq 1 ]];then
+iopts+=" --databases-exclude='lost+found'"
+
+if [ ${FORCE_FTWRL:-0} -eq 1 ]; then
     wsrep_log_info "Forcing FTWRL due to environment variable FORCE_FTWRL equal to $FORCE_FTWRL"
-    iopts+=" --no-backup-locks "
+    iopts+=' --no-backup-locks'
 fi
 
-INNOEXTRA=""
-
 if [[ $ssyslog -eq 1 ]];then
-
     if [[ ! -x `which logger` ]];then
         wsrep_log_error "logger not in path: $PATH. Ignoring"
     else
@@ -876,44 +895,34 @@ if [[ $ssyslog -eq 1 ]];then
         INNOMOVE="2>&1 | logger -p daemon.err -t ${ssystag}innobackupex-move "
         INNOBACKUP="2> >(logger -p daemon.err -t ${ssystag}innobackupex-backup)"
     fi
-
 else
-    INNOAPPLY="&>\${DATA}/innobackup.prepare.log"
-    INNOMOVE="&>\${DATA}/innobackup.move.log"
-    INNOBACKUP="2>\${DATA}/innobackup.backup.log"
+    INNOAPPLY="&>'$DATA/innobackup.prepare.log'"
+    INNOMOVE="&>'$DATA/innobackup.move.log'"
+    INNOBACKUP="2>'$DATA/innobackup.backup.log'"
 fi
 
 get_stream
 get_transfer
 
-INNODB_DATA_HOME_DIR=${INNODB_DATA_HOME_DIR:-""}
-# Try to set INNODB_DATA_HOME_DIR from the command line:
-if [ ! -z "$INNODB_DATA_HOME_DIR_ARG" ]; then
-    INNODB_DATA_HOME_DIR=$INNODB_DATA_HOME_DIR_ARG
-fi
 # if no command line arg and INNODB_DATA_HOME_DIR environment variable
 # is not set, try to get it from my.cnf:
 if [ -z "$INNODB_DATA_HOME_DIR" ]; then
-    INNODB_DATA_HOME_DIR=$(parse_cnf mysqld$WSREP_SST_OPT_SUFFIX_VALUE innodb-data-home-dir '')
-fi
-if [ -z "$INNODB_DATA_HOME_DIR" ]; then
-    INNODB_DATA_HOME_DIR=$(parse_cnf --mysqld innodb-data-home-dir '')
-fi
-if [ ! -z "$INNODB_DATA_HOME_DIR" ]; then
-   INNOEXTRA+=" --innodb-data-home-dir=$INNODB_DATA_HOME_DIR"
+    INNODB_DATA_HOME_DIR=$(parse_cnf --mysqld innodb-data-home-dir)
 fi
 
 if [ -n "$INNODB_DATA_HOME_DIR" ]; then
     # handle both relative and absolute paths
-    INNODB_DATA_HOME_DIR=$(cd $DATA; mkdir -p "$INNODB_DATA_HOME_DIR"; cd $INNODB_DATA_HOME_DIR; pwd -P)
+    INNODB_DATA_HOME_DIR=$(cd "$DATA"; mkdir -p "$INNODB_DATA_HOME_DIR"; cd "$INNODB_DATA_HOME_DIR"; pwd -P)
 else
     # default to datadir
-    INNODB_DATA_HOME_DIR=$(cd $DATA; pwd -P)
+    INNODB_DATA_HOME_DIR=$(cd "$DATA"; pwd -P)
 fi
 
-INNOAPPLY="${INNOBACKUPEX_BIN} $disver $iapts \$INNOEXTRA --apply-log \$rebuildcmd \${DATA} ${INNOAPPLY}"
-INNOMOVE="${INNOBACKUPEX_BIN} ${WSREP_SST_OPT_CONF} $disver $impts  --move-back --force-non-empty-directories \${DATA} ${INNOMOVE}"
-INNOBACKUP="${INNOBACKUPEX_BIN} ${WSREP_SST_OPT_CONF} $disver $iopts \$tmpopts \$INNOEXTRA --galera-info --stream=\$sfmt \$itmpdir ${INNOBACKUP}"
+setup_commands () {
+    INNOAPPLY="$INNOBACKUPEX_BIN $disver $iapts $INNOEXTRA --apply-log $rebuildcmd '$DATA' $INNOAPPLY"
+    INNOMOVE="$INNOBACKUPEX_BIN $WSREP_SST_OPT_CONF $disver $impts --move-back --force-non-empty-directories '$DATA' $INNOMOVE"
+    INNOBACKUP="$INNOBACKUPEX_BIN $WSREP_SST_OPT_CONF $disver $iopts $tmpopts $INNOEXTRA --galera-info --stream='$sfmt' '$itmpdir' $INNOBACKUP"
+}
 
 if [ "$WSREP_SST_OPT_ROLE" = "donor" ]
 then
@@ -922,31 +931,30 @@ then
     if [ $WSREP_SST_OPT_BYPASS -eq 0 ]
     then
         usrst=0
-        if [[ -z $WSREP_SST_OPT_SST_VER ]];then
+        if [ -z "$WSREP_SST_OPT_SST_VER" ]; then
             wsrep_log_error "Upgrade joiner to 5.6.21 or higher for backup locks support"
             wsrep_log_error "The joiner is not supported for this version of donor"
             exit 93
         fi
 
-        if [[ -z $(parse_cnf mysqld$WSREP_SST_OPT_SUFFIX_VALUE tmpdir "") && \
-              -z $(parse_cnf --mysqld tmpdir "") && \
-              -z $(parse_cnf xtrabackup tmpdir "") ]]; then
+        if [ -z "$(parse_cnf --mysqld tmpdir)" -a \
+             -z "$(parse_cnf xtrabackup tmpdir)" ]; then
             xtmpdir=$(mktemp -d)
-            tmpopts=" --tmpdir=$xtmpdir"
+            tmpopts=" --tmpdir='$xtmpdir'"
             wsrep_log_info "Using $xtmpdir as xtrabackup temporary directory"
         fi
 
         itmpdir=$(mktemp -d)
         wsrep_log_info "Using $itmpdir as innobackupex temporary directory"
 
-        if [[ -n "${WSREP_SST_OPT_USER:-}" && "$WSREP_SST_OPT_USER" != "(null)" ]]; then
-           INNOEXTRA+=" --user=$WSREP_SST_OPT_USER"
+        if [ -n "$WSREP_SST_OPT_USER" -a "$WSREP_SST_OPT_USER" != '(null)' ]; then
+           INNOEXTRA+=" --user='$WSREP_SST_OPT_USER'"
            usrst=1
         fi
 
-        if [ -n "${WSREP_SST_OPT_PSWD:-}" ]; then
-            export MYSQL_PWD=$WSREP_SST_OPT_PSWD
-        elif [[ $usrst -eq 1 ]];then
+        if [ -n "$WSREP_SST_OPT_PSWD" ]; then
+            export MYSQL_PWD="$WSREP_SST_OPT_PSWD"
+        elif [ $usrst -eq 1 ]; then
             # Empty password, used for testing, debugging etc.
             unset MYSQL_PWD
         fi
@@ -962,24 +970,24 @@ then
 
         ttcmd="$tcmd"
 
-        if [[ $encrypt -eq 1 ]];then
-            if [[ -n $scomp ]];then
-                tcmd=" \$ecmd | $scomp | $tcmd "
+        if [ $encrypt -eq 1 ]; then
+            if [ -n "$scomp" ]; then
+                tcmd="\$ecmd | $scomp | $tcmd"
             else
-                tcmd=" \$ecmd | $tcmd "
+                tcmd="\$ecmd | $tcmd"
             fi
-        elif [[ -n $scomp ]];then
-            tcmd=" $scomp | $tcmd "
+        elif [ -n "$scomp" ]; then
+            tcmd="$scomp | $tcmd"
         fi
 
         send_donor $DATA "${stagemsg}-gtid"
 
         # Restore the transport commmand to its original state
         tcmd="$ttcmd"
-        if [[ -n $progress ]];then
+        if [ -n "$progress" ]; then
             get_footprint
             tcmd="$pcmd | $tcmd"
-        elif [[ -n $rlimit ]];then
+        elif [ -n "$rlimit" ]; then
             adjust_progress
             tcmd="$pcmd | $tcmd"
         fi
@@ -987,10 +995,10 @@ then
         wsrep_log_info "Sleeping before data transfer for SST"
         sleep 10
 
-        wsrep_log_info "Streaming the backup to joiner at ${WSREP_SST_OPT_HOST} ${WSREP_SST_OPT_PORT:-4444}"
+        wsrep_log_info "Streaming the backup to joiner at ${WSREP_SST_OPT_HOST}:${WSREP_SST_OPT_PORT}"
 
         # Add compression to the head of the stream (if specified)
-        if [[ -n $scomp ]]; then
+        if [[ -n "$scomp" ]]; then
             tcmd="$scomp | $tcmd"
         fi
 
@@ -999,6 +1007,7 @@ then
             tcmd=" \$ecmd | $tcmd "
         fi
 
+        setup_commands
         set +e
         timeit "${stagemsg}-SST" "$INNOBACKUP | $tcmd; RC=( "\${PIPESTATUS[@]}" )"
         set -e
@@ -1025,18 +1034,18 @@ then
         echo "${WSREP_SST_OPT_GTID} ${WSREP_SST_OPT_GTID_DOMAIN_ID}" > "${MAGIC_FILE}"
         echo "1" > "${DATA}/${IST_FILE}"
         get_keys
-        if [[ $encrypt -eq 1 ]];then
-            if [[ -n $scomp ]];then
-                tcmd=" \$ecmd | $scomp | $tcmd "
+        if [ $encrypt -eq 1 ]; then
+            if [ -n "$scomp" ]; then
+                tcmd="\$ecmd | $scomp | $tcmd"
             else
-                tcmd=" \$ecmd | $tcmd "
+                tcmd="\$ecmd | $tcmd"
             fi
-        elif [[ -n $scomp ]];then
-            tcmd=" $scomp | $tcmd "
+        elif [ -n "$scomp" ]; then
+            tcmd="$scomp | $tcmd"
         fi
         strmcmd+=" \${IST_FILE}"
 
-        send_donor $DATA "${stagemsg}-IST"
+        send_donor "$DATA" "${stagemsg}-IST"
 
     fi
 
@@ -1045,29 +1054,26 @@ then
 
 elif [ "${WSREP_SST_OPT_ROLE}" = "joiner" ]
 then
-    [[ -e $SST_PROGRESS_FILE ]] && wsrep_log_info "Stale sst_in_progress file: $SST_PROGRESS_FILE"
-    [[ -n $SST_PROGRESS_FILE ]] && touch $SST_PROGRESS_FILE
+    [[ -e "$SST_PROGRESS_FILE" ]] && wsrep_log_info "Stale sst_in_progress file: $SST_PROGRESS_FILE"
+    [[ -n "$SST_PROGRESS_FILE" ]] && touch "$SST_PROGRESS_FILE"
 
-    ib_home_dir=$INNODB_DATA_HOME_DIR
+    ib_home_dir="$INNODB_DATA_HOME_DIR"
 
-    # Try to set ib_log_dir from the command line:
-    ib_log_dir=$INNODB_LOG_GROUP_HOME_ARG
-    if [ -z "$ib_log_dir" ]; then
-        ib_log_dir=$(parse_cnf mysqld$WSREP_SST_OPT_SUFFIX_VALUE innodb-log-group-home-dir "")
-    fi
-    if [ -z "$ib_log_dir" ]; then
-        ib_log_dir=$(parse_cnf --mysqld innodb-log-group-home-dir "")
+    # if no command line argument and INNODB_LOG_GROUP_HOME is not set,
+    # try to get it from my.cnf:
+    if [ -z "$INNODB_LOG_GROUP_HOME" ]; then
+        INNODB_LOG_GROUP_HOME=$(parse_cnf --mysqld innodb-log-group-home-dir)
     fi
 
-    # Try to set ib_undo_dir from the command line:
-    ib_undo_dir=$INNODB_UNDO_DIR_ARG
-    if [ -z "$ib_undo_dir" ]; then
-        ib_undo_dir=$(parse_cnf mysqld$WSREP_SST_OPT_SUFFIX_VALUE innodb-undo-directory "")
-    fi
-    if [ -z "$ib_undo_dir" ]; then
-        ib_undo_dir=$(parse_cnf --mysqld innodb-undo-directory "")
+    ib_log_dir="$INNODB_LOG_GROUP_HOME"
+
+    # if no command line arg then try to get it from my.cnf:
+    if [ -z "$INNODB_UNDO_DIR" ]; then
+        INNODB_UNDO_DIR=$(parse_cnf --mysqld innodb-undo-directory)
     fi
 
+    ib_undo_dir="$INNODB_UNDO_DIR"
+
     stagemsg="Joiner-Recv"
 
     sencrypted=1
@@ -1078,32 +1084,32 @@ then
     rm -f "${DATA}/${IST_FILE}"
 
     # May need xtrabackup_checkpoints later on
-    rm -f ${DATA}/xtrabackup_binary ${DATA}/xtrabackup_galera_info  ${DATA}/xtrabackup_logfile
+    rm -f "${DATA}/xtrabackup_binary" "${DATA}/xtrabackup_galera_info" "${DATA}/xtrabackup_logfile"
 
-    wait_for_listen ${WSREP_SST_OPT_HOST} ${WSREP_SST_OPT_PORT:-4444} ${MODULE} &
+    wait_for_listen ${WSREP_SST_OPT_HOST} ${WSREP_SST_OPT_PORT} ${MODULE} &
 
     trap sig_joiner_cleanup HUP PIPE INT TERM
     trap cleanup_joiner EXIT
 
-    if [[ -n $progress ]];then
+    if [[ -n "$progress" ]];then
         adjust_progress
         tcmd+=" | $pcmd"
     fi
 
     get_keys
-    if [[ $encrypt -eq 1 && $sencrypted -eq 1 ]];then
-        if [[ -n $sdecomp ]];then
-            strmcmd=" $sdecomp | \$ecmd | $strmcmd"
+    if [ $encrypt -eq 1 -a $sencrypted -eq 1 ]; then
+        if [ -n "$sdecomp" ]; then
+            strmcmd="$sdecomp | \$ecmd | $strmcmd"
         else
-            strmcmd=" \$ecmd | $strmcmd"
+            strmcmd="\$ecmd | $strmcmd"
         fi
-    elif [[ -n $sdecomp ]];then
-            strmcmd=" $sdecomp | $strmcmd"
+    elif [ -n "$sdecomp" ]; then
+            strmcmd="$sdecomp | $strmcmd"
     fi
 
     STATDIR=$(mktemp -d)
     MAGIC_FILE="${STATDIR}/${INFO_FILE}"
-    recv_joiner $STATDIR  "${stagemsg}-gtid" $stimeout 1
+    recv_joiner "$STATDIR" "${stagemsg}-gtid" $stimeout 1
 
     if ! ps -p ${WSREP_SST_OPT_PARENT} &>/dev/null
     then
@@ -1114,12 +1120,12 @@ then
     if [ ! -r "${STATDIR}/${IST_FILE}" ]
     then
 
-        if [[ -d ${DATA}/.sst ]];then
+        if [[ -d "${DATA}/.sst" ]];then
             wsrep_log_info "WARNING: Stale temporary SST directory: ${DATA}/.sst from previous state transfer. Removing"
-            rm -rf ${DATA}/.sst
+            rm -rf "${DATA}/.sst"
         fi
-        mkdir -p ${DATA}/.sst
-        (recv_joiner $DATA/.sst "${stagemsg}-SST" 0 0) &
+        mkdir -p "${DATA}/.sst"
+        (recv_joiner "$DATA/.sst" "${stagemsg}-SST" 0 0) &
         jpid=$!
         wsrep_log_info "Proceeding with SST"
 
@@ -1130,25 +1136,16 @@ then
             find $ib_home_dir $ib_log_dir $ib_undo_dir $DATA -mindepth 1 -prune -regex $cpat -o -exec rm -rfv {} 1>&2 \+
         fi
 
-        tempdir=$LOG_BIN_ARG
-        if [ -z "$tempdir" ]; then
-            tempdir=$(parse_cnf mysqld$WSREP_SST_OPT_SUFFIX_VALUE log-bin "")
-        fi
-        if [ -z "$tempdir" ]; then
-            tempdir=$(parse_cnf --mysqld log-bin "")
-        fi
-        if [[ -n ${tempdir:-} ]];then
-            binlog_dir=$(dirname $tempdir)
-            binlog_file=$(basename $tempdir)
-            if [[ -n ${binlog_dir:-} && $binlog_dir != '.' && $binlog_dir != $DATA ]];then
-                pattern="$binlog_dir/$binlog_file\.[0-9]+$"
-                wsrep_log_info "Cleaning the binlog directory $binlog_dir as well"
-                find $binlog_dir -maxdepth 1 -type f -regex $pattern -exec rm -fv {} 1>&2 \+ || true
-                rm $binlog_dir/*.index || true
-            fi
+        get_binlog
+
+        if [ -n "$WSREP_SST_OPT_BINLOG" ]; then
+            binlog_dir=$(dirname "$WSREP_SST_OPT_BINLOG")
+            wsrep_log_info "Cleaning the binlog directory $binlog_dir as well"
+            rm -fv "$WSREP_SST_OPT_BINLOG".[0-9]* 1>&2 \+ || true
+            rm -fv "$WSREP_SST_OPT_BINLOG_INDEX"  1>&2 \+ || true
         fi
 
-        TDATA=${DATA}
+        TDATA="${DATA}"
         DATA="${DATA}/.sst"
 
         MAGIC_FILE="${DATA}/${INFO_FILE}"
@@ -1157,13 +1154,13 @@ then
 
         get_proc
 
-        if [[ ! -s ${DATA}/xtrabackup_checkpoints ]];then
+        if [[ ! -s "${DATA}/xtrabackup_checkpoints" ]];then
             wsrep_log_error "xtrabackup_checkpoints missing, failed innobackupex/SST on donor"
             exit 2
         fi
 
         # Rebuild indexes for compact backups
-        if grep -q 'compact = 1' ${DATA}/xtrabackup_checkpoints;then
+        if grep -q 'compact = 1' "${DATA}/xtrabackup_checkpoints";then
             wsrep_log_info "Index compaction detected"
             rebuild=1
         fi
@@ -1171,11 +1168,11 @@ then
         if [[ $rebuild -eq 1 ]];then
             nthreads=$(parse_cnf xtrabackup rebuild-threads $nproc)
             wsrep_log_info "Rebuilding during prepare with $nthreads threads"
-            rebuildcmd="--rebuild-indexes --rebuild-threads=$nthreads"
+            rebuildcmd="--rebuild-indexes --rebuild-threads='$nthreads'"
         fi
 
-        if test -n "$(find ${DATA} -maxdepth 1 -type f -name '*.qp' -print -quit)";then
-
+        qpfiles=$(find "${DATA}" -maxdepth 1 -type f -name '*.qp' -print -quit)
+        if [ -n "$qpfiles" ]; then
             wsrep_log_info "Compressed qpress files found"
 
             if [[ ! -x `which qpress` ]];then
@@ -1183,8 +1180,8 @@ then
                 exit 22
             fi
 
-            if [[ -n $progress ]] && pv --help | grep -q 'line-mode';then
-                count=$(find ${DATA} -type f -name '*.qp' | wc -l)
+            if [[ -n "$progress" ]] && pv --help | grep -q 'line-mode';then
+                count=$(find "${DATA}" -type f -name '*.qp' | wc -l)
                 count=$(( count*2 ))
                 if pv --help | grep -q FORMAT;then
                     pvopts="-f -s $count -l -N Decompression -F '%N => Rate:%r Elapsed:%t %e Progress: [%b/$count]'"
@@ -1205,7 +1202,7 @@ then
 
             if [[ $extcode -eq 0 ]];then
                 wsrep_log_info "Removing qpress files after decompression"
-                find ${DATA} -type f -name '*.qp' -delete
+                find "$DATA" -type f -name '*.qp' -delete
                 if [[ $? -ne 0 ]];then
                     wsrep_log_error "Something went wrong with deletion of qpress files. Investigate"
                 fi
@@ -1215,23 +1212,24 @@ then
             fi
         fi
 
-        if  [[ ! -z $WSREP_SST_OPT_BINLOG ]];then
+        if  [ -n "$WSREP_SST_OPT_BINLOG" ]; then
 
-            BINLOG_DIRNAME=$(dirname $WSREP_SST_OPT_BINLOG)
-            BINLOG_FILENAME=$(basename $WSREP_SST_OPT_BINLOG)
+            BINLOG_DIRNAME=$(dirname "$WSREP_SST_OPT_BINLOG")
+            BINLOG_FILENAME=$(basename "$WSREP_SST_OPT_BINLOG")
 
             # To avoid comparing data directory and BINLOG_DIRNAME
-            mv $DATA/${BINLOG_FILENAME}.* $BINLOG_DIRNAME/ 2>/dev/null || true
+            mv "$DATA/$BINLOG_FILENAME".* "$BINLOG_DIRNAME/" 2>/dev/null || true
 
-            pushd $BINLOG_DIRNAME &>/dev/null
-            for bfiles in $(ls -1 ${BINLOG_FILENAME}.[0-9]*);do
-                echo ${BINLOG_DIRNAME}/${bfiles} >> ${BINLOG_FILENAME}.index
+            pushd "$BINLOG_DIRNAME" &>/dev/null
+            for bfile in $(ls -1 "$BINLOG_FILENAME".[0-9]*); do
+                echo "$BINLOG_DIRNAME/$bfile" >> "$WSREP_SST_OPT_BINLOG_INDEX"
             done
             popd &> /dev/null
 
         fi
 
         wsrep_log_info "Preparing the backup at ${DATA}"
+        setup_commands
         timeit "Xtrabackup prepare stage" "$INNOAPPLY"
 
         if [ $? -ne 0 ];
@@ -1242,14 +1240,14 @@ then
 
         MAGIC_FILE="${TDATA}/${INFO_FILE}"
         set +e
-        rm $TDATA/innobackup.prepare.log $TDATA/innobackup.move.log
+        rm "$TDATA/innobackup.prepare.log" "$TDATA/innobackup.move.log"
         set -e
         wsrep_log_info "Moving the backup to ${TDATA}"
         timeit "Xtrabackup move stage" "$INNOMOVE"
         if [[ $? -eq 0 ]];then
             wsrep_log_info "Move successful, removing ${DATA}"
-            rm -rf $DATA
-            DATA=${TDATA}
+            rm -rf "$DATA"
+            DATA="${TDATA}"
         else
             wsrep_log_error "Move failed, keeping ${DATA} for further diagnosis"
             wsrep_log_error "Check ${DATA}/innobackup.move.log for details"
@@ -1260,7 +1258,7 @@ then
         wsrep_log_info "${IST_FILE} received from donor: Running IST"
     fi
 
-    if [[ ! -r ${MAGIC_FILE} ]];then
+    if [[ ! -r "${MAGIC_FILE}" ]];then
         wsrep_log_error "SST magic file ${MAGIC_FILE} not found/readable"
         exit 2
     fi
diff --git a/scripts/wsrep_sst_xtrabackup.sh b/scripts/wsrep_sst_xtrabackup.sh
index df1a7da6e69..c06794e0994 100644
--- a/scripts/wsrep_sst_xtrabackup.sh
+++ b/scripts/wsrep_sst_xtrabackup.sh
@@ -19,6 +19,7 @@
 # Make sure to read that before proceeding!
 
 . $(dirname $0)/wsrep_sst_common
+wsrep_check_datadir
 
 ealgo=""
 ekey=""
@@ -131,7 +132,7 @@ get_keys()
 
 get_transfer()
 {
-    TSST_PORT=${WSREP_SST_OPT_PORT:-4444}
+    TSST_PORT=$WSREP_SST_OPT_PORT
 
     if [[ $tfmt == 'nc' ]];then
         if [[ ! -x `which nc` ]];then
@@ -407,7 +408,6 @@ read_cnf
 get_stream
 get_transfer
 
-INNOEXTRA=""
 INNOAPPLY="${INNOBACKUPEX_BIN} ${WSREP_SST_OPT_CONF} --apply-log \$rebuildcmd \${DATA} &>\${DATA}/innobackup.prepare.log"
 INNOBACKUP="${INNOBACKUPEX_BIN} ${WSREP_SST_OPT_CONF} \$INNOEXTRA --galera-info --stream=\$sfmt \${TMPDIR} 2>\${DATA}/innobackup.backup.log"
 
@@ -420,14 +420,14 @@ then
         usrst=0
         TMPDIR="${TMPDIR:-/tmp}"
 
-        if [[ -n "${WSREP_SST_OPT_USER:-}" && "$WSREP_SST_OPT_USER" != "(null)" ]]; then
+        if [ -n "$WSREP_SST_OPT_USER" -a "$WSREP_SST_OPT_USER" != '(null)' ]; then
            INNOEXTRA+=" --user=$WSREP_SST_OPT_USER"
            usrst=1
         fi
 
-        if [ -n "${WSREP_SST_OPT_PSWD:-}" ]; then
+        if [ -n "$WSREP_SST_OPT_PSWD" ]; then
            INNOEXTRA+=" --password=$WSREP_SST_OPT_PSWD"
-        elif [[ $usrst -eq 1 ]];then
+        elif [ $usrst -eq 1 ]; then
            # Empty password, used for testing, debugging etc.
            INNOEXTRA+=" --password="
         fi
@@ -528,9 +528,9 @@ then
     # May need xtrabackup_checkpoints later on
     rm -f ${DATA}/xtrabackup_binary ${DATA}/xtrabackup_galera_info  ${DATA}/xtrabackup_logfile
 
-    ADDR="${WSREP_SST_OPT_HOST}:${WSREP_SST_OPT_PORT:-4444}"
+    ADDR="${WSREP_SST_OPT_HOST}:${WSREP_SST_OPT_PORT}"
 
-    wait_for_listen ${WSREP_SST_OPT_PORT:-4444} ${ADDR} ${MODULE} &
+    wait_for_listen ${WSREP_SST_OPT_PORT} ${ADDR} ${MODULE} &
 
     trap sig_joiner_cleanup HUP PIPE INT TERM
     trap cleanup_joiner EXIT