Bug#40281, partitioning the general log table crashes the server

We disallow the partitioning of a log table. You could however
partition a table first, and then point logging to it. This is
not only against the docs, it also crashes the server.

We catch this case now.

mysql-test/r/partition.result:
  results for 40281
mysql-test/t/partition.test:
  test for 40281: show that trying to log to partitioned table fails rather
  to crash the server
sql/ha_partition.cc:
  Signal that we no longer support logging to partitioned tables,
  as per the docs.
sql/sql_partition.cc:
  Some commands like "USE ..." have no select, yet we may try
  to parse partition info after their execution if user set a
  partitioned table as log target. This shouldn't lead to a
  NULL-deref/crash.

1 files changed, 34 insertions, 0 deletions

diff --git a/mysql-test/r/partition.result b/mysql-test/r/partition.result
index 8e3fbde1ea8..068d0d2a870 100644
--- a/mysql-test/r/partition.result
+++ b/mysql-test/r/partition.result
@@ -1991,5 +1991,39 @@ CREATE TABLE t1(id INT,KEY(id)) ENGINE=MYISAM
 PARTITION BY HASH(id) PARTITIONS 2;
 DROP TABLE t1;
 SET SESSION SQL_MODE=DEFAULT;
+
+Bug#40281: partitioning the general log table crashes the server
+
+--- set up partitioned log, and switch to it
+USE mysql;
+SET GLOBAL general_log =0;
+CREATE TABLE gl_partitioned LIKE general_log;
+ALTER TABLE gl_partitioned ENGINE=myisam;
+ALTER TABLE gl_partitioned PARTITION BY HASH (thread_id) PARTITIONS 10;
+ALTER TABLE general_log RENAME TO gl_nonpartitioned;
+ALTER TABLE gl_partitioned RENAME TO general_log;
+SELECT @@global.log_output INTO @old_glo;
+SET GLOBAL log_output='table';
+SET GLOBAL general_log =1;
+--- do some things to be logged to partitioned log, should fail
+USE /* 1 */ test;
+CREATE TABLE t1 (i INT);
+INSERT INTO t1 VALUES (1);
+SELECT * FROM t1;
+i
+1
+USE mysql;
+SET GLOBAL general_log =0;
+ALTER TABLE general_log RENAME TO gl_partitioned;
+ALTER TABLE gl_nonpartitioned RENAME TO general_log;
+--- show whether we actually logged anything (no) to general_log
+SELECT COUNT(argument) FROM gl_partitioned;
+COUNT(argument)
+0
+DROP TABLE gl_partitioned;
+SET GLOBAL log_output=@old_glo;
+SET GLOBAL general_log =1;
+USE /* 2 */ test;
+DROP TABLE t1;
 End of 5.1 tests
 SET @@global.general_log= @old_general_log;