Submitted By: Robert Connolly <robert at linuxfromscratch dot org> (ashes)
Date: 2008-05-31
Initial Package Version: 2.5.1
Upstream Status: From Upstream
Origin: CVS
Description: Bug fixes to handle empty string and make results more random.

--- glibc-2.5.1/string/strfry.c	2002-03-11 23:47:45.000000000 +0000
+++ libc/string/strfry.c	2008-03-31 18:30:11.000000000 +0000
@@ -1,4 +1,4 @@
-/* Copyright (C) 1992, 1996, 1999, 2002 Free Software Foundation, Inc.
+/* Copyright (C) 1992, 1996, 1999, 2002, 2007 Free Software Foundation, Inc.
    This file is part of the GNU C Library.
 
    The GNU C Library is free software; you can redistribute it and/or
@@ -26,7 +26,6 @@
 {
   static int init;
   static struct random_data rdata;
-  size_t len, i;
 
   if (!init)
     {
@@ -37,19 +36,18 @@
       init = 1;
     }
 
-  len = strlen (string);
-  for (i = 0; i < len; ++i)
-    {
-      int32_t j;
-      char c;
-
-      __random_r (&rdata, &j);
-      j %= len;
-
-      c = string[i];
-      string[i] = string[j];
-      string[j] = c;
-    }
+  size_t len = strlen (string);
+  if (len > 0)
+    for (size_t i = 0; i < len - 1; ++i)
+      {
+	int32_t j;
+	__random_r (&rdata, &j);
+	j = j % (len - i) + i;
+
+	char c = string[i];
+	string[i] = string[j];
+	string[j] = c;
+      }
 
   return string;
 }