d3d12: Propagate errors when closing command lists (#5125)

Before this commit, command lists that we failed to close were used anyway during submit, causing device loss.

wgpu-core/src/device/queue.rs

@@ -228,18 +228,18 @@ impl<A: HalApi> PendingWrites<A> {
             .push(TempResource::StagingBuffer(buffer));
     }
 
-    #[must_use]
-    fn pre_submit(&mut self) -> Option<&A::CommandBuffer> {
+    fn pre_submit(&mut self) -> Result<Option<&A::CommandBuffer>, DeviceError> {
         self.dst_buffers.clear();
         self.dst_textures.clear();
         if self.is_active {
-            let cmd_buf = unsafe { self.command_encoder.end_encoding().unwrap() };
+            let cmd_buf = unsafe { self.command_encoder.end_encoding()? };
             self.is_active = false;
             self.executing_command_buffers.push(cmd_buf);
-            self.executing_command_buffers.last()
-        } else {
-            None
+
+            return Ok(self.executing_command_buffers.last());
         }
+
+        Ok(None)
     }
 
     #[must_use]
@@ -1463,7 +1463,7 @@ impl<G: GlobalIdentityHandlerFactory> Global<G> {
             }
 
             let refs = pending_writes
-                .pre_submit()
+                .pre_submit()?
                 .into_iter()
                 .chain(
                     active_executions

wgpu-hal/src/dx12/command.rs

@@ -289,14 +289,13 @@ impl crate::CommandEncoder<super::Api> for super::CommandEncoder {
     }
     unsafe fn end_encoding(&mut self) -> Result<super::CommandBuffer, crate::DeviceError> {
         let raw = self.list.take().unwrap();
-        let closed = raw.close().into_result().is_ok();
-        Ok(super::CommandBuffer { raw, closed })
+        raw.close()
+            .into_device_result("GraphicsCommandList::close")?;
+        Ok(super::CommandBuffer { raw })
     }
     unsafe fn reset_all<I: Iterator<Item = super::CommandBuffer>>(&mut self, command_buffers: I) {
         for cmd_buf in command_buffers {
-            if cmd_buf.closed {
-                self.free_lists.push(cmd_buf.raw);
-            }
+            self.free_lists.push(cmd_buf.raw);
         }
         self.allocator.reset();
     }

wgpu-hal/src/dx12/mod.rs

@@ -386,7 +386,6 @@ impl fmt::Debug for CommandEncoder {
 #[derive(Debug)]
 pub struct CommandBuffer {
     raw: d3d12::GraphicsCommandList,
-    closed: bool,
 }
 
 unsafe impl Send for CommandBuffer {}