Another fix for #2208

previous one had error

libmysqld/lib_sql.cc

@@ -251,7 +251,7 @@ int emb_next_result(MYSQL *mysql)
   DBUG_ENTER("emb_next_result");
 
   if (emb_advanced_command(mysql, COM_QUERY,0,0,
-			   thd->query_rest,thd->query_rest_length,1)
+			   thd->query_rest.ptr(),thd->query_rest.length(),1)
       || emb_mysql_read_query_result(mysql))
     DBUG_RETURN(1);
 
@@ -765,11 +765,6 @@ bool Protocol::net_store_data(const char *from, uint length)
   return false;
 }
 
-char *memdup_mysql(struct st_mysql *mysql, const char*data, int length)
-{
-  return memdup_root(&mysql->field_alloc, data, length);
-}
-
 #if 0
 /* The same as Protocol::net_store_data but does the converstion
 */

sql/sql_class.h

@@ -565,8 +565,7 @@ public:
   struct st_mysql_bind *client_params;
   char *extra_data;
   ulong extra_length;
-  char *query_rest;
-  uint32 query_rest_length;
+  String query_rest;
 #endif
   NET	  net;				// client connection descriptor
   MEM_ROOT warn_root;			// For warnings and errors

sql/sql_parse.cc

@@ -48,7 +48,6 @@
 extern "C" int gethostname(char *name, int namelen);
 #endif
 
-char *memdup_mysql(struct st_mysql *mysql, const char*data, int length);
 static int check_for_max_user_connections(THD *thd, USER_CONN *uc);
 static void decrease_user_connections(USER_CONN *uc);
 static bool check_db_used(THD *thd,TABLE_LIST *tables);
@@ -1420,8 +1419,17 @@ bool dispatch_command(enum enum_server_command command, THD *thd,
 #ifndef EMBEDDED_LIBRARY
       mysql_parse(thd, packet, length);
 #else
-      thd->query_rest= (char*)memdup_mysql(thd->mysql, packet, length);
-      thd->query_rest_length= length;
+      /*
+	'packet' can point inside the query_rest's buffer
+	so we have to do memmove here
+       */
+      if (thd->query_rest.length() > length)
+      {
+	memmove(thd->query_rest.c_ptr(), packet, length);
+	thd->query_rest.length(length);
+      }
+      else
+	thd->query_rest.copy(length);
       break;
 #endif /*EMBEDDED_LIBRARY*/
     }