mesa: Unbind ARB_transform_feedback2 binding points on Delete too.

DeleteBuffer needs to unbind from these binding points as well, based on
the same rationale as the previous patch.

+51 oglconforms (together with the last patch).

NOTE: This is a candidate for stable release branches.

Signed-off-by: Kenneth Graunke <kenneth@whitecape.org>
Reviewed-by: Brian Paul <brianp@vmware.com>

src/mesa/main/bufferobj.c

@@ -42,6 +42,7 @@
 #include "mfeatures.h"
 #include "mtypes.h"
 #include "texobj.h"
+#include "transformfeedback.h"
 
 
 /* Debug flags */
@@ -829,10 +830,15 @@ _mesa_DeleteBuffersARB(GLsizei n, const GLuint *ids)
             _mesa_BindBufferARB( GL_COPY_WRITE_BUFFER, 0 );
          }
 
-         /* unbind transform feedback binding point */
+         /* unbind transform feedback binding points */
          if (ctx->TransformFeedback.CurrentBuffer == bufObj) {
             _mesa_BindBufferARB( GL_TRANSFORM_FEEDBACK_BUFFER, 0 );
          }
+         for (j = 0; j < MAX_FEEDBACK_ATTRIBS; j++) {
+            if (ctx->TransformFeedback.CurrentObject->Buffers[j] == bufObj) {
+               _mesa_BindBufferBase( GL_TRANSFORM_FEEDBACK_BUFFER, j, 0 );
+            }
+         }
 
          /* unbind any pixel pack/unpack pointers bound to this buffer */
          if (ctx->Pack.BufferObj == bufObj) {