Mesa (master): meta: Don't call _mesa_Ortho with width or height of 0

[Ian Romanick]

Module: Mesa
Branch: master
Commit: 341fb93c162052e0b1eff7f5e53c49aba498ee9a
URL:    http://cgit.freedesktop.org/mesa/mesa/commit/?id=341fb93c162052e0b1eff7f5e53c49aba498ee9a

Author: Ian Romanick <ian.d.romanick at intel.com>
Date:   Thu Aug  8 12:33:04 2013 -0700

meta: Don't call _mesa_Ortho with width or height of 0

Fixes failures in oglconform fbo mipmap.manual.color,
mipmap.manual.colorAndDepth, mipmap.automatic, and
mipmap.manualIterateTexTargets subtests.

Signed-off-by: Ian Romanick <ian.d.romanick at intel.com>
Reviewed-by: Chad Versace <chad.versace at linux.intel.com>
Cc: "9.2" <mesa-stable at lists.freedesktop.org>

---

 src/mesa/drivers/common/meta.c |   11 ++++++++---
 1 files changed, 8 insertions(+), 3 deletions(-)

diff --git a/src/mesa/drivers/common/meta.c b/src/mesa/drivers/common/meta.c
index c62927c..69b06ed 100644
--- a/src/mesa/drivers/common/meta.c
+++ b/src/mesa/drivers/common/meta.c
@@ -704,9 +704,14 @@ _mesa_meta_begin(struct gl_context *ctx, GLbitfield state)
       _mesa_LoadIdentity();
       _mesa_MatrixMode(GL_PROJECTION);
       _mesa_LoadIdentity();
-      _mesa_Ortho(0.0, ctx->DrawBuffer->Width,
-                  0.0, ctx->DrawBuffer->Height,
-                  -1.0, 1.0);
+
+      /* glOrtho with width = 0 or height = 0 generates GL_INVALID_VALUE.
+       * This can occur when there is no draw buffer.
+       */
+      if (ctx->DrawBuffer->Width != 0 && ctx->DrawBuffer->Height != 0)
+         _mesa_Ortho(0.0, ctx->DrawBuffer->Width,
+                     0.0, ctx->DrawBuffer->Height,
+                     -1.0, 1.0);
    }
 
    if (state & MESA_META_CLIP) {