bzr commit into mysql-5.1 branch (chad:2712)

[Chad MILLER]

#At file:///home/cmiller/work/mysqlbzr/mysql-5.1-bugteam/

 2712 Chad MILLER	2008-08-18 [merge]
      Merge from 5.0-bugteam local.
modified:
  mysys/mf_pack.c

=== modified file 'mysys/mf_pack.c'
--- a/mysys/mf_pack.c	2008-07-17 17:45:08 +0000
+++ b/mysys/mf_pack.c	2008-08-18 17:11:55 +0000
@@ -354,7 +354,7 @@ size_t unpack_dirname(char * to, const c
       length-= (size_t) (suffix-buff)-1;
       if (length+(h_length= strlen(tilde_expansion)) <= FN_REFLEN)
       {
-	if (tilde_expansion[h_length-1] == FN_LIBCHAR)
+	if ((h_length > 0) && (tilde_expansion[h_length-1] == FN_LIBCHAR))
 	  h_length--;
 	if (buff+h_length < suffix)
 	  bmove(buff+h_length,suffix,length);