# 3362 Staale Smedseng	2010-02-26
#      Bug #45058 init_available_charsets uses double checked locking
#      
#      A client doing multiple mysql_library_init() and
#      mysql_library_end() calls over the lifetime of the process may
#      experience lost character set data, potentially even a
#      SIGSEGV.
#      
#      This patch reinstates the reloading of character set data when
#      a mysql_library_init() is done after a mysql_library_end().
#
=== modified file 'include/my_sys.h'
--- a/include/my_sys.h	2009-12-12 18:11:25 +0000
+++ b/include/my_sys.h	2010-02-26 14:30:14 +0000
@@ -950,7 +950,7 @@ extern my_bool resolve_charset(const cha
 extern my_bool resolve_collation(const char *cl_name,
                                  CHARSET_INFO *default_cl,
                                  CHARSET_INFO **cl);
-
+extern void free_charsets(void);
 extern char *get_charsets_dir(char *buf);
 extern my_bool my_charset_same(CHARSET_INFO *cs1, CHARSET_INFO *cs2);
 extern my_bool init_compiled_charsets(myf flags);

=== modified file 'libmysql/libmysql.c'
--- a/libmysql/libmysql.c	2009-12-18 18:44:24 +0000
+++ b/libmysql/libmysql.c	2010-02-26 14:30:14 +0000
@@ -211,6 +211,7 @@ void STDCALL mysql_server_end()
   }
   else
   {
+    free_charsets();
     mysql_thread_end();
   }
 

=== modified file 'mysys/charset.c'
--- a/mysys/charset.c	2009-12-15 09:48:29 +0000
+++ b/mysys/charset.c	2010-02-26 14:30:14 +0000
@@ -427,6 +427,11 @@ static void init_available_charsets(void
 }
 
 
+void free_charsets(void)
+{
+  charsets_initialized= MY_PTHREAD_ONCE_INIT;
+}
+
 uint get_collation_number(const char *name)
 {
   my_pthread_once(&charsets_initialized, init_available_charsets);

=== modified file 'mysys/my_init.c'
--- a/mysys/my_init.c	2009-12-12 18:11:25 +0000
+++ b/mysys/my_init.c	2010-02-26 14:30:14 +0000
@@ -165,6 +165,7 @@ void my_end(int infoflag)
       my_print_open_files();
     }
   }
+  free_charsets();
   my_error_unregister_all();
   my_once_free();
 

=== modified file 'sql/mysqld.cc'
--- a/sql/mysqld.cc	2010-02-05 12:55:20 +0000
+++ b/sql/mysqld.cc	2010-02-26 14:30:14 +0000
@@ -1287,6 +1287,7 @@ void clean_up(bool print_message)
   lex_free();				/* Free some memory */
   item_create_cleanup();
   set_var_free();
+  free_charsets();
   if (!opt_noacl)
   {
 #ifdef HAVE_DLOPEN