BUG#34656 - KILL a query = Assertion failed: m_status == DA_ERROR ||

            m_status == DA_OK

Reading from information_scema.tables or information_schema.columns
may cause assertion failure in debug builds. This may happen under
rare circumstances when information_schema fails to get information
about a table (e.g. when a connection is killed).

This happens because open_normal_and_derived_tables() can return an
error without setting an error message in THD. But information_schema
attempts to get an error message from THD unconditionally.

With this fix information_schema attempts to get an error message
from THD only in case error message is set in THD.

1 files changed, 2 insertions, 0 deletions

diff --git a/sql/item_func.cc b/sql/item_func.cc
index 65d3a627d2d..b61f683ae9f 100644
--- a/sql/item_func.cc
+++ b/sql/item_func.cc
@@ -3722,6 +3722,7 @@ longlong Item_func_sleep::val_int()
   pthread_cond_init(&cond, NULL);
   pthread_mutex_lock(&LOCK_user_locks);
 
+  thd_proc_info(thd, "User sleep");
   thd->mysys_var->current_mutex= &LOCK_user_locks;
   thd->mysys_var->current_cond=  &cond;
 
@@ -3733,6 +3734,7 @@ longlong Item_func_sleep::val_int()
       break;
     error= 0;
   }
+  thd_proc_info(thd, 0);
   pthread_mutex_unlock(&LOCK_user_locks);
   pthread_mutex_lock(&thd->mysys_var->mutex);
   thd->mysys_var->current_mutex= 0;