Fix up CreateTextureViewError::TooMany{MipLevels,ArrayLayers} crashes and style

CHANGELOG.md

@@ -51,6 +51,7 @@ Bottom level categories:
 
 - BREAKING: Migrated from the `maxInterStageShaderComponents` limit to `maxInterStageShaderVariables`, which changes validation in a way that should not affect most programs. This follows the latest changes of the WebGPU spec. By @ErichDonGubler in [#8652](https://github.com/gfx-rs/wgpu/pull/8652).
 - Fixed validation of the texture format in GPUDepthStencilState when neither depth nor stencil is actually enabled. By @andyleiserson in [#8766](https://github.com/gfx-rs/wgpu/pull/8766).
+- Don't crash in the `Display` implementation of `CreateTextureViewError::TooMany{MipLevels,ArrayLayers}` when their base and offset overflow. By @ErichDonGubler in [8808](https://github.com/gfx-rs/wgpu/pull/8808).
 
 #### GLES
 

wgpu-core/src/resource.rs

@@ -1800,19 +1800,19 @@ pub enum CreateTextureViewError {
     #[error("Array layer count is 0")]
     ZeroArrayLayerCount,
     #[error(
-        "TextureView spans mip levels [{base_mip_level}, {end_mip_level}) \
-        (mipLevelCount {mip_level_count}) but the texture view only has {total} total mip levels",
-        end_mip_level = base_mip_level + mip_level_count
+        "`TextureView` spans mip levels [{base_mip_level}, {end_mip_level}) \
+        (`mipLevelCount` is {mip_level_count}) but the texture view only has {total} total mip level(s))",
+        end_mip_level = BasePlusOffset(*base_mip_level, *mip_level_count)
     )]
     TooManyMipLevels {
         base_mip_level: u32,
         mip_level_count: u32,
         total: u32,
     },
     #[error(
-        "TextureView spans array layers [{base_array_layer}, {end_array_layer}) \
-         (arrayLayerCount {array_layer_count}) but the texture view only has {total} total layers",
-        end_array_layer = base_array_layer + array_layer_count
+        "`TextureView` spans array layers [{base_array_layer}, {end_array_layer}) \
+         (`arrayLayerCount` is {array_layer_count}) but the texture view only has {total} total layer(s))",
+        end_array_layer = BasePlusOffset(*base_array_layer, *array_layer_count)
     )]
     TooManyArrayLayers {
         base_array_layer: u32,
@@ -1872,6 +1872,20 @@ impl WebGpuError for CreateTextureViewError {
     }
 }
 
+/// Diagnostic structure for [`Display`](fmt::Display)'ing a base + offset calculation, accounting
+/// for overflow.
+struct BasePlusOffset(u32, u32);
+
+impl fmt::Display for BasePlusOffset {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        let &Self(base, offset) = self;
+        match base.checked_add(offset) {
+            Some(sum) => fmt::Display::fmt(&sum, f),
+            None => write!(f, "<overflow>"),
+        }
+    }
+}
+
 #[derive(Clone, Debug, Error)]
 #[non_exhaustive]
 pub enum TextureViewDestroyError {}