[intel] Allow attIndex to be negative to avoid defeating the >= 0 check.

Otherwise, we would go wildly out of bounds if passed -1 (no renderbuffer), such
as while doing LOCK_HARDWARE with glDrawBuffer(GL_NONE).

1 files changed, 1 insertions, 1 deletions

diff --git a/src/mesa/drivers/dri/intel/intel_fbo.c b/src/mesa/drivers/dri/intel/intel_fbo.c
index c430e90382..94d499f001 100644
--- a/src/mesa/drivers/dri/intel/intel_fbo.c
+++ b/src/mesa/drivers/dri/intel/intel_fbo.c
@@ -69,7 +69,7 @@ intel_renderbuffer(struct gl_renderbuffer *rb)
 
 
 struct intel_renderbuffer *
-intel_get_renderbuffer(struct gl_framebuffer *fb, GLuint attIndex)
+intel_get_renderbuffer(struct gl_framebuffer *fb, int attIndex)
 {
    if (attIndex >= 0)
       return intel_renderbuffer(fb->Attachment[attIndex].Renderbuffer);