From: Neil Roberts <neil@linux.intel.com>
Date: Tue, 8 Dec 2015 16:35:57 +0000 (+0000)
Subject: i965: Fix crash when calling glViewport with no surface bound
X-Git-Tag: upstream/17.1.0~13647
X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=8c5310da9d1cbf2272f72d3ed4264544456a4683;p=platform%2Fupstream%2Fmesa.git

i965: Fix crash when calling glViewport with no surface bound

If EGL_KHR_surfaceless_context is used then glViewport can be called
with NULL for the draw and read surfaces. This was previously causing
a crash because the i965 driver tries to use this point to invalidate
the surfaces and it was derferencing the NULL pointer.

Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=93257
Cc: Nanley Chery <nanley.g.chery@intel.com>
Cc: "11.1" <mesa-stable@lists.freedesktop.org>
Tested-by: Nanley Chery <nanley.g.chery@intel.com>
Reviewed-by: Nanley Chery <nanley.g.chery@intel.com>
---

diff --git a/src/mesa/drivers/dri/i965/brw_context.c b/src/mesa/drivers/dri/i965/brw_context.c
index 0abe601..de4bc2c 100644
--- a/src/mesa/drivers/dri/i965/brw_context.c
+++ b/src/mesa/drivers/dri/i965/brw_context.c
@@ -159,8 +159,10 @@ intel_viewport(struct gl_context *ctx)
    __DRIcontext *driContext = brw->driContext;
 
    if (_mesa_is_winsys_fbo(ctx->DrawBuffer)) {
-      dri2InvalidateDrawable(driContext->driDrawablePriv);
-      dri2InvalidateDrawable(driContext->driReadablePriv);
+      if (driContext->driDrawablePriv)
+         dri2InvalidateDrawable(driContext->driDrawablePriv);
+      if (driContext->driReadablePriv)
+         dri2InvalidateDrawable(driContext->driReadablePriv);
    }
 }