From 7a75fcd6573fa5ec85dfe40cca73c4e2a5fc263e Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Marek=20Ol=C5=A1=C3=A1k?= <maraeo@gmail.com>
Date: Sun, 10 Jul 2011 20:01:33 +0200
Subject: [PATCH] mesa: return early if mask is cleared to zero in
 BlitFramebuffer

From ARB_framebuffer_object:
    If a buffer is specified in <mask> and does not exist in both the
    read and draw framebuffers, the corresponding bit is silently
    ignored.
(cherry picked from commit 83478e5d5944e1fc320e8cfb10ba75055bbea3fd)
---
 src/mesa/main/fbobject.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/src/mesa/main/fbobject.c b/src/mesa/main/fbobject.c
index e5fa1bf79c0..dbba6bb9b1f 100644
--- a/src/mesa/main/fbobject.c
+++ b/src/mesa/main/fbobject.c
@@ -2447,6 +2447,10 @@ _mesa_BlitFramebufferEXT(GLint srcX0, GLint srcY0, GLint srcX1, GLint srcY1,
       }
    }
 
+   if (!mask) {
+      return;
+   }
+
    ASSERT(ctx->Driver.BlitFramebuffer);
    ctx->Driver.BlitFramebuffer(ctx,
                                srcX0, srcY0, srcX1, srcY1,