bzr commit into mysql-5.1-bugteam branch (davi:2696) Bug#38560

[Davi Arnaut]

# At a local mysql-5.1-bugteam repository of davi

 2696 Davi Arnaut	2008-08-13
      Bug#38560: valgrind warnings on PB due to query profiling
      
      Backport 6.0 fix for this problem:
      
      Fix for a valgrind warning due to a jump on a uninitialized
      variable. The problem was that the sql profile preparation
      function wasn't being called for all possible code paths
      of query execution. The solution is to move the preparation
      to the dispatch_command function and to explicitly call the
      profile preparation function on bootstrap.
modified:
  sql/sql_parse.cc

per-file messages:
  sql/sql_parse.cc
    Move profile prepare of new query to dispatch_command.
    This is safe because dispatch_command is not reentrant.
    Finish query profiling properly when executing bootstrap
    commands.
=== modified file 'sql/sql_parse.cc'
--- a/sql/sql_parse.cc	2008-08-07 02:23:58 +0000
+++ b/sql/sql_parse.cc	2008-08-13 16:13:47 +0000
@@ -441,6 +441,7 @@ pthread_handler_t handle_bootstrap(void 
     thd->query[length] = '\0';
     DBUG_PRINT("query",("%-.4096s",thd->query));
 #if defined(ENABLED_PROFILING) && defined(COMMUNITY_SERVER)
+    thd->profiling.start_new_query();
     thd->profiling.set_query_source(thd->query, length);
 #endif
 
@@ -456,6 +457,10 @@ pthread_handler_t handle_bootstrap(void 
     bootstrap_error= thd->is_error();
     net_end_statement(thd);
 
+#if defined(ENABLED_PROFILING) && defined(COMMUNITY_SERVER)
+    thd->profiling.finish_current_query();
+#endif
+
     if (bootstrap_error)
       break;
 
@@ -733,11 +738,7 @@ bool do_command(THD *thd)
 
   net_new_transaction(net);
 
-  packet_length= my_net_read(net);
-#if defined(ENABLED_PROFILING) && defined(COMMUNITY_SERVER)
-  thd->profiling.start_new_query();
-#endif
-  if (packet_length == packet_error)
+  if ((packet_length= my_net_read(net)) == packet_error)
   {
     DBUG_PRINT("info",("Got error %d reading command from socket %s",
 		       net->error,
@@ -794,9 +795,6 @@ bool do_command(THD *thd)
   return_value= dispatch_command(command, thd, packet+1, (uint) (packet_length-1));
 
 out:
-#if defined(ENABLED_PROFILING) && defined(COMMUNITY_SERVER)
-  thd->profiling.finish_current_query();
-#endif
   DBUG_RETURN(return_value);
 }
 #endif  /* EMBEDDED_LIBRARY */
@@ -898,6 +896,10 @@ bool dispatch_command(enum enum_server_c
   DBUG_ENTER("dispatch_command");
   DBUG_PRINT("info",("packet: '%*.s'; command: %d", packet_length, packet, command));
 
+#if defined(ENABLED_PROFILING) && defined(COMMUNITY_SERVER)
+  thd->profiling.start_new_query();
+#endif
+
   thd->command=command;
   /*
     Commands which always take a long time are logged into
@@ -1519,6 +1521,11 @@ bool dispatch_command(enum enum_server_c
   VOID(pthread_mutex_unlock(&LOCK_thread_count));
   thd->packet.shrink(thd->variables.net_buffer_length);	// Reclaim some memory
   free_root(thd->mem_root,MYF(MY_KEEP_PREALLOC));
+
+#if defined(ENABLED_PROFILING) && defined(COMMUNITY_SERVER)
+  thd->profiling.finish_current_query();
+#endif
+
   DBUG_RETURN(error);
 }