From 5c18db7fe9195567812f7fcfe4283c430eb70f6b Mon Sep 17 00:00:00 2001
From: "Ryan C. Gordon" <icculus@icculus.org>
Date: Thu, 7 Jun 2012 10:21:43 -0400
Subject: [PATCH] Don't sort if there's nothing to do (prevents array
 underflow, too).

---
 src/physfs.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/src/physfs.c b/src/physfs.c
index 9498a9b..f57837e 100644
--- a/src/physfs.c
+++ b/src/physfs.c
@@ -657,7 +657,8 @@ void __PHYSFS_sort(void *entries, size_t max,
      * Quicksort w/ Bubblesort fallback algorithm inspired by code from here:
      *   http://www.cs.ubc.ca/spider/harrison/Java/sorting-demo.html
      */
-    __PHYSFS_quick_sort(entries, 0, max - 1, cmpfn, swapfn);
+    if (max > 0)
+        __PHYSFS_quick_sort(entries, 0, max - 1, cmpfn, swapfn);
 } /* __PHYSFS_sort */