BUG#32943: Fixed buggy lock handling of ALTER TABLE for partitioning

mysql-test/r/partition_range.result:
  Added new test cases for lock tables and ALTER TABLE for
  partitions, also added a test case with a trigger.
mysql-test/t/partition_range.test:
  Added new test cases for lock tables and ALTER TABLE for
  partitions, also added a test case with a trigger.
sql/mysql_priv.h:
  Added WFRM_KEEP_SHARE for use of code not to be used otherwise
sql/sql_partition.cc:
  Removed get_name_lock and release_name_lock, use
  close_data_files_and_morph_locks which leaves an
  exclusive name lock after completing.
  Reopen table after completing if under lock tables
  Updated comments
sql/sql_table.cc:
  Ensure that code to set partition syntax isn't used other than
  when specifically asked to do it.

1 files changed, 7 insertions, 3 deletions

diff --git a/sql/sql_table.cc b/sql/sql_table.cc
index 505bcd1b421..a0464d43372 100644
--- a/sql/sql_table.cc
+++ b/sql/sql_table.cc
@@ -1226,8 +1226,12 @@ uint build_table_shadow_filename(char *buff, size_t bufflen,
     flags                  Flags as defined below
       WFRM_INITIAL_WRITE        If set we need to prepare table before
                                 creating the frm file
-      WFRM_CREATE_HANDLER_FILES If set we need to create the handler file as
-                                part of the creation of the frm file
+      WFRM_INSTALL_SHADOW       If set we should install the new frm
+      WFRM_KEEP_SHARE           If set we know that the share is to be
+                                retained and thus we should ensure share
+                                object is correct, if not set we don't
+                                set the new partition syntax string since
+                                we know the share object is destroyed.
       WFRM_PACK_FRM             If set we should pack the frm file and delete
                                 the frm file
 
@@ -1370,7 +1374,7 @@ bool mysql_write_frm(ALTER_PARTITION_PARAM_TYPE *lpt, uint flags)
       goto err;
     }
 #ifdef WITH_PARTITION_STORAGE_ENGINE
-    if (part_info)
+    if (part_info && (flags & WFRM_KEEP_SHARE))
     {
       TABLE_SHARE *share= lpt->table->s;
       char *tmp_part_syntax_str;