Bug #40877: multi statement execution fails in 5.1.30

      
Implemented the server infrastructure for the fix:

1. Added a function LEX_STRING *thd_query_string(THD) to return
a LEX_STRING structure instead of char *.
This is the function that must be called in innodb instead of 
thd_query()

2. Did some encapsulation in THD : aggregated thd_query and 
thd_query_length into a LEX_STRING and made accessor and mutator 
methods for easy code updating. 

3. Updated the server code to use the new methods where applicable.

1 files changed, 9 insertions, 9 deletions

diff --git a/sql/sql_db.cc b/sql/sql_db.cc
index c19bfba9fc1..e6ccd9aa594 100644
--- a/sql/sql_db.cc
+++ b/sql/sql_db.cc
@@ -703,7 +703,7 @@ not_silent:
     char *query;
     uint query_length;
 
-    if (!thd->query)				// Only in replication
+    if (!thd->query())                          // Only in replication
     {
       query= 	     tmp_query;
       query_length= (uint) (strxmov(tmp_query,"create database `",
@@ -711,8 +711,8 @@ not_silent:
     }
     else
     {
-      query= 	    thd->query;
-      query_length= thd->query_length;
+      query=        thd->query();
+      query_length= thd->query_length();
     }
 
     ha_binlog_log_query(thd, 0, LOGCOM_CREATE_DB,
@@ -805,13 +805,13 @@ bool mysql_alter_db(THD *thd, const char *db, HA_CREATE_INFO *create_info)
   }
 
   ha_binlog_log_query(thd, 0, LOGCOM_ALTER_DB,
-                      thd->query, thd->query_length,
+                      thd->query(), thd->query_length(),
                       db, "");
 
   if (mysql_bin_log.is_open())
   {
     int errcode= query_error_code(thd, TRUE);
-    Query_log_event qinfo(thd, thd->query, thd->query_length, 0,
+    Query_log_event qinfo(thd, thd->query(), thd->query_length(), 0,
 			  /* suppress_use */ TRUE, errcode);
 
     /*
@@ -948,7 +948,7 @@ bool mysql_rm_db(THD *thd,char *db,bool if_exists, bool silent)
   {
     const char *query;
     ulong query_length;
-    if (!thd->query)
+    if (!thd->query())
     {
       /* The client used the old obsolete mysql_drop_db() call */
       query= path;
@@ -957,8 +957,8 @@ bool mysql_rm_db(THD *thd,char *db,bool if_exists, bool silent)
     }
     else
     {
-      query =thd->query;
-      query_length= thd->query_length;
+      query= thd->query();
+      query_length= thd->query_length();
     }
     if (mysql_bin_log.is_open())
     {
@@ -1964,7 +1964,7 @@ bool mysql_upgrade_db(THD *thd, LEX_STRING *old_db)
   if (mysql_bin_log.is_open())
   {
     int errcode= query_error_code(thd, TRUE);
-    Query_log_event qinfo(thd, thd->query, thd->query_length,
+    Query_log_event qinfo(thd, thd->query(), thd->query_length(),
                           0, TRUE, errcode);
     thd->clear_error();
     mysql_bin_log.write(&qinfo);