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.


mysql-test/r/information_schema.result:
  A test case for BUG#34656.
mysql-test/t/information_schema.test:
  A test case for BUG#34656.
sql/item_func.cc:
  Set proc info to "User sleep".
sql/sql_show.cc:
  open_normal_and_derived_tables() can return an error without
  setting an error message in THD. That means we must access
  error message conditionally, only in case thd->is_error() is
  true.

1 files changed, 44 insertions, 0 deletions

diff --git a/mysql-test/t/information_schema.test b/mysql-test/t/information_schema.test
index 6e76a043645..9f99f0fe32b 100644
--- a/mysql-test/t/information_schema.test
+++ b/mysql-test/t/information_schema.test
@@ -1270,4 +1270,48 @@ show open tables where f1()=0;
 drop table t1;
 drop function f1;
 
+#
+# BUG#34656 - KILL a query = Assertion failed: m_status == DA_ERROR ||
+#             m_status == DA_OK
+#
+connect (conn1, localhost, root,,);
+connection conn1;
+let $ID= `select connection_id()`;
+send select * from information_schema.tables where 1=sleep(100000);
+connection default;
+let $wait_timeout= 10;
+let $wait_condition=select count(*)=1 from information_schema.processlist
+where state='User sleep' and
+info='select * from information_schema.tables where 1=sleep(100000)';
+--source include/wait_condition.inc
+disable_query_log;
+eval kill $ID;
+enable_query_log;
+disconnect conn1;
+let $wait_timeout= 10;
+let $wait_condition=select count(*)=0 from information_schema.processlist
+where state='User sleep' and
+info='select * from information_schema.tables where 1=sleep(100000)';
+--source include/wait_condition.inc
+
+connect (conn1, localhost, root,,);
+connection conn1;
+let $ID= `select connection_id()`;
+send select * from information_schema.columns where 1=sleep(100000);
+connection default;
+let $wait_timeout= 10;
+let $wait_condition=select count(*)=1 from information_schema.processlist
+where state='User sleep' and
+info='select * from information_schema.columns where 1=sleep(100000)';
+--source include/wait_condition.inc
+disable_query_log;
+eval kill $ID;
+enable_query_log;
+disconnect conn1;
+let $wait_timeout= 10;
+let $wait_condition=select count(*)=0 from information_schema.processlist
+where state='User sleep' and
+info='select * from information_schema.columns where 1=sleep(100000)';
+--source include/wait_condition.inc
+
 --echo End of 5.1 tests.