Bug#13437900 - VALGRIND REPORTS A LEAK FOR REPL_IGNORE_SERVER_IDS

There was memory leak when running some tests on PB2.
The reason of the failure is an early return from change_master()
that was supposed to deallocate a dyn-array.

Actually the same bug58915 was fixed in trunk with relocating the dyn-array
destruction into THD::cleanup_after_query() which can't be bypassed.
The current patch backports magne.mahre@oracle.com-20110203101306-q8auashb3d7icxho
and adds two optimizations: were done: the static buffer for the dyn-array to base on,
and the array initialization is called precisely when it's necessary rather than
per each CHANGE-MASTER as before.

mysql-test/suite/rpl/t/rpl_empty_master_host.test

@@ -17,6 +17,7 @@
 #   working when expected.
 
 --source include/master-slave.inc
+--source include/have_binlog_format_mixed.inc
 
 connection slave;
 STOP SLAVE;

mysql-test/suite/rpl/t/rpl_server_id_ignore.test

@@ -18,6 +18,7 @@
 #       executing events this time
 
 source include/master-slave.inc;
+source include/have_binlog_format_mixed.inc;
 
 connection slave;
 

sql/sql_class.cc

@@ -1673,6 +1673,11 @@ void THD::cleanup_after_query()
   /* reset table map for multi-table update */
   table_map_for_update= 0;
   m_binlog_invoker= FALSE;
+  /* reset replication info structure */
+  if (lex && lex->mi.repl_ignore_server_ids.buffer) 
+  {
+    delete_dynamic(&lex->mi.repl_ignore_server_ids);
+  }
 }
 
 

sql/sql_lex.cc

@@ -2351,6 +2351,7 @@ LEX::LEX()
                          plugins_static_buffer,
                          INITIAL_LEX_PLUGIN_LIST_SIZE, 
                          INITIAL_LEX_PLUGIN_LIST_SIZE);
+  memset(&mi, 0, sizeof(LEX_MASTER_INFO));
   reset_query_tables_list(TRUE);
 }
 

sql/sql_lex.h

@@ -292,6 +292,7 @@ typedef struct st_lex_master_info
   char *relay_log_name;
   ulong relay_log_pos;
   DYNAMIC_ARRAY repl_ignore_server_ids;
+  typeof(::server_id) server_ids_buffer[2];
 } LEX_MASTER_INFO;
 
 typedef struct st_lex_reset_slave

sql/sql_repl.cc

@@ -1689,7 +1689,6 @@ err:
   thd_proc_info(thd, 0);
   if (ret == FALSE)
     my_ok(thd);
-  delete_dynamic(&lex_mi->repl_ignore_server_ids); //freeing of parser-time alloc
   DBUG_RETURN(ret);
 }
 

sql/sql_yacc.yy

@@ -1863,12 +1863,9 @@ change:
             LEX *lex = Lex;
             lex->sql_command = SQLCOM_CHANGE_MASTER;
             bzero((char*) &lex->mi, sizeof(lex->mi));
-            /*
-              resetting flags that can left from the previous CHANGE MASTER
-            */
             lex->mi.repl_ignore_server_ids_opt= LEX_MASTER_INFO::LEX_MI_UNCHANGED;
-            my_init_dynamic_array(&Lex->mi.repl_ignore_server_ids,
-                                  sizeof(::server_id), 16, 16);
+
+            DBUG_ASSERT(Lex->mi.repl_ignore_server_ids.elements == 0);
           }
           master_defs
           {}
@@ -1979,6 +1976,14 @@ ignore_server_id_list:
 ignore_server_id:
           ulong_num
           {
+            if (Lex->mi.repl_ignore_server_ids.elements == 0)
+            {
+              my_init_dynamic_array2(&Lex->mi.repl_ignore_server_ids,
+                                     sizeof(::server_id),
+                                     Lex->mi.server_ids_buffer,
+                                     array_elements(Lex->mi.server_ids_buffer),
+                                     16);
+            }
             insert_dynamic(&Lex->mi.repl_ignore_server_ids, (uchar*) &($1));
           }