=== modified file 'mysys/my_lib.c'
--- mysys/my_lib.c  2013-04-07 13:19:45 +0000
+++ mysys/my_lib.c  2013-07-01 03:24:05 +0000
@@ -99,8 +99,10 @@
   if (src[0] == 0)
     src= (char*) ".";                           /* Use empty as current */
   end=strmov(dst, src);
-  if (end[-1] != FN_LIBCHAR + 1)
+  if (end[-1] == FN_LIBCHAR)
   {
+    return end;
+  } else {
     *end++= FN_LIBCHAR;                          /* Add last '/' */
     *end='\0';
   }