cookie.c: Made cookie sort function more deterministic

Since qsort implementations vary with regards to handling the order
of similiar elements, this change makes the internal sort function
more deterministic by comparing path length first, then domain length
and finally the cookie name. Spotted with testcase 62 on Windows.

lib/cookie.c

@@ -5,7 +5,7 @@
  *                            | (__| |_| |  _ <| |___
  *                             \___|\___/|_| \_\_____|
  *
- * Copyright (C) 1998 - 2012, Daniel Stenberg, <daniel@haxx.se>, et al.
+ * Copyright (C) 1998 - 2013, Daniel Stenberg, <daniel@haxx.se>, et al.
  *
  * This software is licensed as described in the file COPYING, which
  * you should have received as part of this distribution. The terms
@@ -777,11 +777,28 @@ static int cookie_sort(const void *p1, const void *p2)
 {
   struct Cookie *c1 = *(struct Cookie **)p1;
   struct Cookie *c2 = *(struct Cookie **)p2;
+  size_t l1, l2;
 
-  size_t l1 = c1->path?strlen(c1->path):0;
-  size_t l2 = c2->path?strlen(c2->path):0;
+  /* 1 - compare cookie path lengths */
+  l1 = c1->path ? strlen(c1->path) : 0;
+  l2 = c2->path ? strlen(c2->path) : 0;
 
-  return (l2 > l1) ? 1 : (l2 < l1) ? -1 : 0 ;
+  if(l1 != l2)
+    return (l2 > l1) ? 1 : -1 ; /* avoid size_t <=> int conversions */
+
+  /* 2 - compare cookie domain lengths */
+  l1 = c1->domain ? strlen(c1->domain) : 0;
+  l2 = c2->domain ? strlen(c2->domain) : 0;
+
+  if(l1 != l2)
+    return (l2 > l1) ? 1 : -1 ;  /* avoid size_t <=> int conversions */
+
+  /* 3 - compare cookie names */
+  if(c1->name && c2->name)
+    return strcmp(c1->name, c2->name);
+
+  /* sorry, can't be more deterministic */
+  return 0;
 }
 
 /*****************************************************************************