From 064c1b2cac3ee742d0384edcc4b1988a8c8eba60 Mon Sep 17 00:00:00 2001
From: Davi Arnaut <Davi.Arnaut@Sun.COM>
Date: Thu, 9 Apr 2009 12:25:25 -0300
Subject: [PATCH] Bug#43706: libmysqld segfaults when re-intialised Bug#44091:
 libmysqld gets stuck waiting on mutex on initialization

The problem was that libmysqld wasn't enforcing a certain
initialization and deinitialization order for the mysys
library. Another problem was that the global object used
for management of log event handlers (aka LOGGER) wasn't
being prepared for a possible reutilization.

What leads to the hang/crash reported is that a failure
to load the language file triggers a double call of the
cleanup functions, causing an already destroyed mutex to
be used.

The solution is enforce a order on the initialization and
deinitialization of the mysys library within the libmysqld
library and to ensure that the global LOGGER object reset
it's internal state during cleanup.
---
 mysys/my_init.c | 4 ++++
 sql/log.cc      | 5 +++++
 2 files changed, 9 insertions(+)

diff --git a/mysys/my_init.c b/mysys/my_init.c
index b330ffac65a..a60927be693 100644
--- a/mysys/my_init.c
+++ b/mysys/my_init.c
@@ -136,6 +136,10 @@ void my_end(int infoflag)
   */
   FILE *info_file= DBUG_FILE;
   my_bool print_info= (info_file != stderr);
+
+  if (!my_init_done)
+    return;
+
   /*
     We do not use DBUG_ENTER here, as after cleanup DBUG is no longer
     operational, so we cannot use DBUG_RETURN.
diff --git a/sql/log.cc b/sql/log.cc
index 44296daa939..ed2eff6625d 100644
--- a/sql/log.cc
+++ b/sql/log.cc
@@ -845,6 +845,7 @@ void LOGGER::cleanup_base()
   {
     table_log_handler->cleanup();
     delete table_log_handler;
+    table_log_handler= NULL;
   }
   if (file_log_handler)
     file_log_handler->cleanup();
@@ -855,7 +856,11 @@ void LOGGER::cleanup_end()
 {
   DBUG_ASSERT(inited == 1);
   if (file_log_handler)
+  {
     delete file_log_handler;
+    file_log_handler=NULL;
+  }
+  inited= 0;
 }