Merge branch '10.0' into 10.1

1 files changed, 4 insertions, 6 deletions

diff --git a/sql/sql_class.cc b/sql/sql_class.cc
index 63663cdd037..4df257b96a4 100644
--- a/sql/sql_class.cc
+++ b/sql/sql_class.cc
@@ -691,12 +691,6 @@ extern "C"
   @param buffer pointer to preferred result buffer
   @param length length of buffer
   @param max_query_len how many chars of query to copy (0 for all)
-
-  @req LOCK_thread_count
-  
-  @note LOCK_thread_count mutex is not necessary when the function is invoked on
-   the currently running thread (current_thd) or if the caller in some other
-   way guarantees that access to thd->query is serialized.
  
   @return Pointer to string
 */
@@ -710,6 +704,9 @@ char *thd_get_error_context_description(THD *thd, char *buffer,
   const Security_context *sctx= &thd->main_security_ctx;
   char header[256];
   int len;
+
+  mysql_mutex_lock(&LOCK_thread_count);
+
   /*
     The pointers thd->query and thd->proc_info might change since they are
     being modified concurrently. This is acceptable for proc_info since its
@@ -765,6 +762,7 @@ char *thd_get_error_context_description(THD *thd, char *buffer,
     }
     mysql_mutex_unlock(&thd->LOCK_thd_data);
   }
+  mysql_mutex_unlock(&LOCK_thread_count);
 
   if (str.c_ptr_safe() == buffer)
     return buffer;