[Mesa-dev] [PATCH] st/dri: fix a crash in server_wait_Sync

[Marek Olšák]

From: Marek Olšák <marek.olsak at amd.com>

Ported from i965 including the comment.

This fixes:
    dEQP-EGL.functional.reusable_sync.valid.wait_server

Cc: 18.1 <mesa-stable at lists.freedesktop.org>
---
 src/gallium/state_trackers/dri/dri_helpers.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/src/gallium/state_trackers/dri/dri_helpers.c b/src/gallium/state_trackers/dri/dri_helpers.c
index f1501bfb815..5d42873a208 100644
--- a/src/gallium/state_trackers/dri/dri_helpers.c
+++ b/src/gallium/state_trackers/dri/dri_helpers.c
@@ -207,20 +207,26 @@ dri2_client_wait_sync(__DRIcontext *_ctx, void *_fence, unsigned flags,
       return false;
    }
 }
 
 static void
 dri2_server_wait_sync(__DRIcontext *_ctx, void *_fence, unsigned flags)
 {
    struct pipe_context *ctx = dri_context(_ctx)->st->pipe;
    struct dri2_fence *fence = (struct dri2_fence*)_fence;
 
+   /* We might be called here with a NULL fence as a result of WaitSyncKHR
+    * on a EGL_KHR_reusable_sync fence. Nothing to do here in such case.
+    */
+   if (!fence)
+      return;
+
    if (ctx->fence_server_sync)
       ctx->fence_server_sync(ctx, fence->pipe_fence);
 }
 
 const __DRI2fenceExtension dri2FenceExtension = {
    .base = { __DRI2_FENCE, 2 },
 
    .create_fence = dri2_create_fence,
    .get_fence_from_cl_event = dri2_get_fence_from_cl_event,
    .destroy_fence = dri2_destroy_fence,
-- 
2.17.1