From: Date: September 12 2007 11:13am
Subject: bk commit into 5.1 tree (aelkin:1.2571) BUG#26000
List-Archive: http://lists.mysql.com/commits/34078
X-Bug: 26000
Message-Id: <200709120913.l8C9DAww023178@koti.dsl.inet.fi>

Below is the list of changes that have just been committed into a local
5.1 repository of elkin. When elkin does a push these changes will
be propagated to the main repository and, within 24 hours after the
push, to the public repository.
For information on how to access the public repository
see http://dev.mysql.com/doc/mysql/en/installing-source-tree.html

ChangeSet@stripped, 2007-09-12 12:13:00+03:00, aelkin@stripped +1 -0
  Bug #26000 SHOW SLAVE STATUS can crash mysqld during shutdown process
  
  active_mi has been reset at the time of quering with SHOW SLAVE STATUS.
  The handler reads members of the struct that segfaults.
  
  Fixed with ingoring show_master_info() execution if active_mi is reset.
  
  Notice, there are more analogical cases in the code which require a similar
  treatment (to be reported as a bug separately).  

  sql/sql_parse.cc@stripped, 2007-09-12 12:12:54+03:00, aelkin@stripped +10 -1
    Ignore reporting if master info struct has been destoyed. As this must be at shutdown merely a warning
    is sent to the client.

diff -Nrup a/sql/sql_parse.cc b/sql/sql_parse.cc
--- a/sql/sql_parse.cc	2007-08-10 23:35:20 +03:00
+++ b/sql/sql_parse.cc	2007-09-12 12:12:54 +03:00
@@ -2052,7 +2052,16 @@ mysql_execute_command(THD *thd)
     if (check_global_access(thd, SUPER_ACL | REPL_CLIENT_ACL))
       goto error;
     pthread_mutex_lock(&LOCK_active_mi);
-    res = show_master_info(thd,active_mi);
+    if (active_mi != NULL)
+    {
+      res = show_master_info(thd, active_mi);
+    }
+    else
+    {
+      push_warning(thd, MYSQL_ERROR::WARN_LEVEL_WARN, 0,
+                   "the master info structure does not exist");
+      send_ok(thd);
+    }
     pthread_mutex_unlock(&LOCK_active_mi);
     break;
   }