Fix Vulkan surface capabilities being advertised when its query failed. (#6510)

Author: Wumpf

CHANGELOG.md

@@ -53,6 +53,10 @@ Bottom level categories:
 
 - Fix surface creation crashing on iOS. By @mockersf in [#6535](https://github.com/gfx-rs/wgpu/pull/6535)
 
+#### Vulkan
+
+- Fix surface capabilities being advertised when its query failed. By @wumpf in [#6510](https://github.com/gfx-rs/wgpu/pull/6510)
+
 ## 23.0.0 (2024-10-25)
 
 ### Themes of this release

wgpu-core/src/instance.rs

@@ -412,13 +412,13 @@ impl Surface {
         &self,
         adapter: &hal::DynExposedAdapter,
     ) -> Result<hal::SurfaceCapabilities, GetSurfaceSupportError> {
+        let backend = adapter.backend();
         let suf = self
-            .raw(adapter.backend())
-            .ok_or(GetSurfaceSupportError::Unsupported)?;
+            .raw(backend)
+            .ok_or(GetSurfaceSupportError::NotSupportedByBackend(backend))?;
         profiling::scope!("surface_capabilities");
         let caps = unsafe { adapter.adapter.surface_capabilities(suf) }
-            .ok_or(GetSurfaceSupportError::Unsupported)?;
-
+            .ok_or(GetSurfaceSupportError::FailedToRetrieveSurfaceCapabilitiesForAdapter)?;
         Ok(caps)
     }
 
@@ -649,8 +649,10 @@ crate::impl_storage_item!(Adapter);
 #[derive(Clone, Debug, Error)]
 #[non_exhaustive]
 pub enum GetSurfaceSupportError {
-    #[error("Surface is not supported by the adapter")]
-    Unsupported,
+    #[error("Surface is not supported for the specified backend {0}")]
+    NotSupportedByBackend(Backend),
+    #[error("Failed to retrieve surface capabilities for the specified adapter.")]
+    FailedToRetrieveSurfaceCapabilitiesForAdapter,
 }
 
 #[derive(Clone, Debug, Error)]

wgpu-hal/src/vulkan/adapter.rs

@@ -2254,7 +2254,8 @@ impl crate::Adapter for super::Adapter {
                 Ok(present_modes) => present_modes,
                 Err(e) => {
                     log::error!("get_physical_device_surface_present_modes: {}", e);
-                    Vec::new()
+                    // Per definition of `SurfaceCapabilities`, there must be at least one present mode.
+                    return None;
                 }
             }
         };
@@ -2269,7 +2270,8 @@ impl crate::Adapter for super::Adapter {
                 Ok(formats) => formats,
                 Err(e) => {
                     log::error!("get_physical_device_surface_formats: {}", e);
-                    Vec::new()
+                    // Per definition of `SurfaceCapabilities`, there must be at least one present format.
+                    return None;
                 }
             }
         };

wgpu/src/backend/wgpu_core.rs

@@ -702,10 +702,7 @@ impl crate::Context for ContextWgpuCore {
             .surface_get_capabilities(surface_data.id, *adapter_data)
         {
             Ok(caps) => caps,
-            Err(wgc::instance::GetSurfaceSupportError::Unsupported) => {
-                wgt::SurfaceCapabilities::default()
-            }
-            Err(err) => self.handle_error_fatal(err, "Surface::get_supported_formats"),
+            Err(_) => wgt::SurfaceCapabilities::default(),
         }
     }