mesa/main: Prevent sefgault on glGetIntegerv(GL_ATOMIC_COUNTER_BUFFER_BINDING).

A recent ApiTrace change, that tries to dump more buffer state
causes Mesa from my distro (10.1.4) to segfaults here.

I haven't actually confirm this fixes it (I can't repro on master),
but it seems a good idea to be defensive here anyway.

Cc: "10.1 10.2" <mesa-stable@lists.freedesktop.org>
Reviewed-by: Kenneth Graunke <kenneth@whitecape.org>

diff --git a/src/mesa/main/get.c b/src/mesa/main/get.c
index 267b5f20cc34b915af6dff05be6ab8c80c6e8472..9b56edb741b5699a625c4b6af544ba99c51b9bdd 100644 (file)
--- a/src/mesa/main/get.c
+++ b/src/mesa/main/get.c
@@ -1005,7 +1005,11 @@ find_custom_value(struct gl_context *ctx, const struct value_desc *d, union valu
       break;
    /* GL_ARB_shader_atomic_counters */
    case GL_ATOMIC_COUNTER_BUFFER_BINDING:
-      v->value_int = ctx->AtomicBuffer->Name;
+      if (ctx->AtomicBuffer) {
+         v->value_int = ctx->AtomicBuffer->Name;
+      } else {
+         v->value_int = 0;
+      }
       break;
    /* GL_ARB_draw_indirect */
    case GL_DRAW_INDIRECT_BUFFER_BINDING: