* Fix for BUG#1248: "LOAD DATA FROM MASTER drops the slave's db unexpectedly".

Now LOAD DATA FROM MASTER does not drop the database, instead it only tries to
create it, and drops/creates table-by-table.
* replicate_wild_ignore_table='db1.%' is now considered as "ignore the 'db1'
database as a whole", as it already works for CREATE DATABASE and DROP DATABASE.


mysql-test/r/rpl000009.result:
  result update
mysql-test/t/rpl000009.test:
  test that LOAD DATA FROM MASTER does not drop databases,
  but rather table by table, thus preserving non-replicated tables.
  Test that LOAD DATA FROM MASTER reports the error when a table could not
  be dropped (system's "permission denied" for example).
  Test that LOAD TABLE FROM MASTER reports the error when the table already exists.
sql/repl_failsafe.cc:
  * replicate_wild_ignore_table='db1.%' is now considered as "ignore the 'db1'
  database as a whole", as it already works for CREATE DATABASE and DROP DATABASE.
  * If a db matches replicate_*_db rules, we don't drop/recreate it because this
  could drop some tables in this db which could be slave-specific. Instead,
  we do a CREATE DATABASE IF EXISTS, and we will drop each table which has
  an equivalent on the master, table-by-table.
sql/slave.cc:
  New argument to drop the table in create_table_from_dump() 
  (LOAD TABLE/DATA FROM MASTER are the only places where this function is used).
  This is needed because LOAD DATA FROM MASTER does not drop the database anymore.
  The behaviour when the table exists is unchanged: LOAD DATA silently replaces
  the table, LOAD TABLE gives error.
sql/slave.h:
  new argument to drop the table in fetch_master_table
sql/sql_parse.cc:
  do not drop the table in LOAD TABLE FROM MASTER (this behaviour is already
  true; but changes in LOAD DATA FROM MASTER made the argument needed).

1 files changed, 33 insertions, 12 deletions

diff --git a/sql/slave.cc b/sql/slave.cc
index 1bc8dfc5b78..10d451a88bc 100644
--- a/sql/slave.cc
+++ b/sql/slave.cc
@@ -72,7 +72,7 @@ static int safe_sleep(THD* thd, int sec, CHECK_KILLED_FUNC thread_killed,
 		      void* thread_killed_arg);
 static int request_table_dump(MYSQL* mysql, const char* db, const char* table);
 static int create_table_from_dump(THD* thd, NET* net, const char* db,
-				  const char* table_name);
+				  const char* table_name, bool overwrite);
 static int check_master_version(MYSQL* mysql, MASTER_INFO* mi);
 
 
@@ -1033,12 +1033,22 @@ static int check_master_version(MYSQL* mysql, MASTER_INFO* mi)
   return 0;
 }
 
+/*
+  Used by fetch_master_table (used by LOAD TABLE tblname FROM MASTER and LOAD
+  DATA FROM MASTER). Drops the table (if 'overwrite' is true) and recreates it
+  from the dump. Honours replication inclusion/exclusion rules.
+
+  RETURN VALUES
+    0           success
+    1           error
+*/
 
 static int create_table_from_dump(THD* thd, NET* net, const char* db,
-				  const char* table_name)
+				  const char* table_name, bool overwrite)
 {
   ulong packet_len = my_net_read(net); // read create table statement
   char *query;
+  char* save_db;
   Vio* save_vio;
   HA_CHECK_OPT check_opt;
   TABLE_LIST tables;
@@ -1078,13 +1088,24 @@ static int create_table_from_dump(THD* thd, NET* net, const char* db,
   thd->current_tablenr = 0;
   thd->query_error = 0;
   thd->net.no_send_ok = 1;
+
+  bzero((char*) &tables,sizeof(tables));
+  tables.db = (char*)db;
+  tables.alias= tables.real_name= (char*)table_name;
+  /* Drop the table if 'overwrite' is true */
+  if (overwrite && mysql_rm_table(thd,&tables,1)) /* drop if exists */
+  {
+    send_error(&thd->net);
+    sql_print_error("create_table_from_dump: failed to drop the table");
+    goto err;
+  }
   
-  /* we do not want to log create table statement */
+  /* Create the table. We do not want to log the "create table" statement */
   save_options = thd->options;
   thd->options &= ~(ulong) (OPTION_BIN_LOG);
   thd->proc_info = "Creating table from master dump";
   // save old db in case we are creating in a different database
-  char* save_db = thd->db;
+  save_db = thd->db;
   thd->db = (char*)db;
   mysql_parse(thd, thd->query, packet_len); // run create table
   thd->db = save_db;		// leave things the way the were before
@@ -1093,11 +1114,8 @@ static int create_table_from_dump(THD* thd, NET* net, const char* db,
   if (thd->query_error)
     goto err;			// mysql_parse took care of the error send
 
-  bzero((char*) &tables,sizeof(tables));
-  tables.db = (char*)db;
-  tables.alias= tables.real_name= (char*)table_name;
-  tables.lock_type = TL_WRITE;
   thd->proc_info = "Opening master dump table";
+  tables.lock_type = TL_WRITE;
   if (!open_ltable(thd, &tables, TL_WRITE))
   {
     send_error(&thd->net,0,0);			// Send error from open_ltable
@@ -1107,10 +1125,11 @@ static int create_table_from_dump(THD* thd, NET* net, const char* db,
   
   file = tables.table->file;
   thd->proc_info = "Reading master dump table data";
+  /* Copy the data file */
   if (file->net_read_dump(net))
   {
     net_printf(&thd->net, ER_MASTER_NET_READ);
-    sql_print_error("create_table_from_dump::failed in\
+    sql_print_error("create_table_from_dump: failed in\
  handler::net_read_dump()");
     goto err;
   }
@@ -1125,6 +1144,7 @@ static int create_table_from_dump(THD* thd, NET* net, const char* db,
   */
   save_vio = thd->net.vio;
   thd->net.vio = 0;
+  /* Rebuild the index file from the copied data file (with REPAIR) */
   error=file->repair(thd,&check_opt) != 0;
   thd->net.vio = save_vio;
   if (error)
@@ -1137,7 +1157,7 @@ err:
 }
 
 int fetch_master_table(THD *thd, const char *db_name, const char *table_name,
-		       MASTER_INFO *mi, MYSQL *mysql)
+		       MASTER_INFO *mi, MYSQL *mysql, bool overwrite)
 {
   int error= 1;
   const char *errmsg=0;
@@ -1169,9 +1189,10 @@ int fetch_master_table(THD *thd, const char *db_name, const char *table_name,
     errmsg= "Failed on table dump request";
     goto err;
   }
+
   if (create_table_from_dump(thd, &mysql->net, db_name,
-			    table_name))
-    goto err;    // create_table_from_dump will have sent the error already
+			    table_name, overwrite))
+    goto err; // create_table_from_dump will have send_error already
   error = 0;
 
  err: