bk commit into 4.1 tree (bar:1.2347) BUG#12109

[bar]

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

ChangeSet
  1.2347 05/07/25 21:34:20 bar@stripped +1 -0
  charset.c:
    Bug#12109 possible locking bug in init_available_charset
    Recheck charset_initialized inside locked code,
    to garantee two threads are not entering
    consequently.

  mysys/charset.c
    1.136 05/07/25 21:32:40 bar@stripped +18 -16
    Bug#12109 possible locking bug in init_available_charset
    Recheck charset_initialized inside locked code,
    to garantee two threads are not entering
    consequently.

# This is a BitKeeper patch.  What follows are the unified diffs for the
# set of deltas contained in the patch.  The rest of the patch, the part
# that BitKeeper cares about, is below these diffs.
# User:	bar
# Host:	bar.intranet.mysql.r18.ru
# Root:	/usr/home/bar/mysql-4.1.b12109

--- 1.135/mysys/charset.c	2005-02-22 16:37:07 +04:00
+++ 1.136/mysys/charset.c	2005-07-25 21:32:40 +05:00
@@ -383,26 +383,28 @@
       while we may changing the cs_info_table
     */
     pthread_mutex_lock(&THR_LOCK_charset);
-
-    bzero(&all_charsets,sizeof(all_charsets));
-    init_compiled_charsets(myflags);
-    
-    /* Copy compiled charsets */
-    for (cs=all_charsets;
-	 cs < all_charsets+array_elements(all_charsets)-1 ;
-	 cs++)
+    if (!charset_initialized)
     {
-      if (*cs)
+      bzero(&all_charsets,sizeof(all_charsets));
+      init_compiled_charsets(myflags);
+      
+      /* Copy compiled charsets */
+      for (cs=all_charsets;
+           cs < all_charsets+array_elements(all_charsets)-1 ;
+           cs++)
       {
-        if (cs[0]->ctype)
-          if (init_state_maps(*cs))
-            *cs= NULL;
+        if (*cs)
+        {
+          if (cs[0]->ctype)
+            if (init_state_maps(*cs))
+              *cs= NULL;
+        }
       }
+      
+      strmov(get_charsets_dir(fname), MY_CHARSET_INDEX);
+      error= my_read_charset_file(fname,myflags);
+      charset_initialized=1;
     }
-    
-    strmov(get_charsets_dir(fname), MY_CHARSET_INDEX);
-    error= my_read_charset_file(fname,myflags);
-    charset_initialized=1;
     pthread_mutex_unlock(&THR_LOCK_charset);
   }
   return error;