Bug #27816: Log tables ran with partitions crashes the server

 when logging is enabled.
Currently the partition engine doesn't allow log tables to
be partitioned. But this was not checked and the server crashed.
Fixed by adding a check in ALTER TABLE to disable partitioning the
log tables.
While working on the cause of the problem improved the way the log
thread structures are initialized before opening the log tables.


mysql-test/r/partition.result:
  Bug #27816: test case
mysql-test/t/partition.test:
  Bug #27816: test case
sql/log.cc:
  Bug #27816: optional
   Improved initialization of the log threads before opening 
   the log table.
   Remedies problems that arise from open_table() et. al. 
   depending on a correctly initialized thd.
   Prerequisite for handling partitioned log tables :
   they call the parser while reading the .frm file.
sql/sql_table.cc:
  Bug #27816: throw an error when paritioning the log tables : 
   not supported by the partition engine.

4 files changed, 47 insertions, 13 deletions

diff --git a/mysql-test/r/partition.result b/mysql-test/r/partition.result
index af90ac6c714..090ee4b7734 100644
--- a/mysql-test/r/partition.result
+++ b/mysql-test/r/partition.result
@@ -1245,4 +1245,12 @@ INSERT INTO t1 SELECT a + 8, b FROM t1;
 ALTER TABLE t1 ADD PARTITION (PARTITION p1 VALUES LESS THAN (64));
 ALTER TABLE t1 DROP PARTITION p1;
 DROP TABLE t1;
+USE mysql;
+SET GLOBAL general_log = 0;
+ALTER TABLE general_log ENGINE = MyISAM;
+ALTER TABLE general_log PARTITION BY RANGE (TO_DAYS(event_time))
+(PARTITION p0 VALUES LESS THAN (733144), PARTITION p1 VALUES LESS THAN (3000000));
+ERROR HY000: Incorrect usage of PARTITION and log table
+ALTER TABLE general_log ENGINE = CSV;
+SET GLOBAL general_log = default;
 End of 5.1 tests
diff --git a/mysql-test/t/partition.test b/mysql-test/t/partition.test
index 186cf1d3e8a..358b0501e32 100644
--- a/mysql-test/t/partition.test
+++ b/mysql-test/t/partition.test
@@ -1465,4 +1465,18 @@ ALTER TABLE t1 DROP PARTITION p1;
 
 DROP TABLE t1;
 
+#
+# Bug #27816: Log tables ran with partitions crashes the server when logging
+# is enabled.
+#
+
+USE mysql;
+SET GLOBAL general_log = 0;
+ALTER TABLE general_log ENGINE = MyISAM;
+--error ER_WRONG_USAGE
+ALTER TABLE general_log PARTITION BY RANGE (TO_DAYS(event_time))
+  (PARTITION p0 VALUES LESS THAN (733144), PARTITION p1 VALUES LESS THAN (3000000));
+ALTER TABLE general_log ENGINE = CSV;
+SET GLOBAL general_log = default;
+
 --echo End of 5.1 tests
diff --git a/sql/log.cc b/sql/log.cc
index 6ef1c1ea912..ac6ea92c61a 100644
--- a/sql/log.cc
+++ b/sql/log.cc
@@ -296,6 +296,8 @@ bool Log_to_csv_event_handler::open_log_table(uint log_table_type)
   table->db= log_thd->db;
   table->db_length= log_thd->db_length;
 
+  lex_start(log_thd);
+  log_thd->clear_error();
   if (simple_open_n_lock_tables(log_thd, table) ||
       table->table->file->extra(HA_EXTRA_MARK_AS_LOG_TABLE) ||
       table->table->file->ha_rnd_init(0))
diff --git a/sql/sql_table.cc b/sql/sql_table.cc
index 04e0fd70ece..343222aba0c 100644
--- a/sql/sql_table.cc
+++ b/sql/sql_table.cc
@@ -5747,21 +5747,31 @@ bool mysql_alter_table(THD *thd,char *new_db, char *new_name,
                                    table_list->table_name_length,
                                    table_list->table_name, 0);
 
-    /* Disable alter of enabled log tables */
-    if (table_kind && logger.is_log_table_enabled(table_kind))
+    if (table_kind)
     {
-      my_error(ER_BAD_LOG_STATEMENT, MYF(0), "ALTER");
-      DBUG_RETURN(TRUE);
-    }
+      /* Disable alter of enabled log tables */
+      if (logger.is_log_table_enabled(table_kind))
+      {
+        my_error(ER_BAD_LOG_STATEMENT, MYF(0), "ALTER");
+        DBUG_RETURN(TRUE);
+      }
 
-    /* Disable alter of log tables to unsupported engine */
-    if (table_kind &&
-        (create_info->used_fields & HA_CREATE_USED_ENGINE) &&
-        (!create_info->db_type || /* unknown engine */
-        !(create_info->db_type->flags & HTON_SUPPORT_LOG_TABLES)))
-    {
-      my_error(ER_UNSUPORTED_LOG_ENGINE, MYF(0));
-      DBUG_RETURN(TRUE);
+      /* Disable alter of log tables to unsupported engine */
+      if ((create_info->used_fields & HA_CREATE_USED_ENGINE) &&
+          (!create_info->db_type || /* unknown engine */
+           !(create_info->db_type->flags & HTON_SUPPORT_LOG_TABLES)))
+      {
+        my_error(ER_UNSUPORTED_LOG_ENGINE, MYF(0));
+        DBUG_RETURN(TRUE);
+      }
+
+#ifdef WITH_PARTITION_STORAGE_ENGINE
+      if (alter_info->flags & ALTER_PARTITION)
+      {
+	my_error(ER_WRONG_USAGE, MYF(0), "PARTITION", "log table");
+        DBUG_RETURN(TRUE);
+      }
+#endif
     }
   }