From 023ce7f6c850998fe41f5a3f06f8aaf6d8fbbcff Mon Sep 17 00:00:00 2001
From: Dzmitry Malyshau <kvarkus@gmail.com>
Date: Tue, 18 Feb 2020 22:55:54 -0500
Subject: [PATCH] Catch swapchain output being dropped too early

---
 wgpu-core/src/device/mod.rs | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/wgpu-core/src/device/mod.rs b/wgpu-core/src/device/mod.rs
index ec88db2b2..a86f26546 100644
--- a/wgpu-core/src/device/mod.rs
+++ b/wgpu-core/src/device/mod.rs
@@ -1369,6 +1369,9 @@ impl<F: AllIdentityFilter + IdentityFilter<id::CommandBufferId>> Global<F> {
 
                 if let Some((sc_id, fbo)) = comb.used_swap_chain.take() {
                     let sc = &mut swap_chain_guard[sc_id.value];
+                    assert!(sc.acquired_view_id.is_some(),
+                        "SwapChainOutput for {:?} was dropped before the respective command buffer {:?} got submitted!",
+                        sc_id.value, cmb_id);
                     if sc.acquired_framebuffers.is_empty() {
                         signal_swapchain_semaphores.push(sc_id.value);
                     }