From: Brian Paul <brian.paul@tungstengraphics.com>
Date: Fri, 4 Jul 2008 15:59:43 +0000 (-0600)
Subject: gallium: fix trim() function bug when count < first
X-Git-Url: https://git.libre-soc.org/?a=commitdiff_plain;h=ba9e6339028c36269cb50bb8535e415fa8e6e4c9;p=mesa.git

gallium: fix trim() function bug when count < first

If the user called glDrawArrays(GL_TRIANGLES, count=1), trim() returned a
very large integer because of the unsigned arithmetic.
---

diff --git a/src/gallium/auxiliary/draw/draw_pt.c b/src/gallium/auxiliary/draw/draw_pt.c
index 9140faeea9d..85a75525c8b 100644
--- a/src/gallium/auxiliary/draw/draw_pt.c
+++ b/src/gallium/auxiliary/draw/draw_pt.c
@@ -37,6 +37,8 @@
 
 static unsigned trim( unsigned count, unsigned first, unsigned incr )
 {
+   if (count < first)
+      return 0;
    return count - (count - first) % incr; 
 }