From e632325fb42516c39cf4a4df11738de952171897 Mon Sep 17 00:00:00 2001
From: Corentin Wallez <[email protected]>
Date: Wed, 20 May 2026 02:42:52 -0700
Subject: [PATCH] [dawn][native] Dirty the validation aspect on SetIndexBuffer

When the CommandBufferStateTracker was introduced, there was no format
parameter to SetIndexBuffer so the validation aspect was always valid
after the first SetIndexBuffer call. However with the introduction of
the IndexFormat, we now need to dirty the aspect so that on the next
draw, the IndexFormat is checked for compatibility between the pipeline
and SetIndexBuffer.

Fixed: 513947609
Change-Id: I8c23968b44b5d090af5c8a717d4504718dfabe2e
Reviewed-on: https://dawn-review.googlesource.com/c/dawn/+/309395
Reviewed-by: Brandon Jones <[email protected]>
Commit-Queue: Corentin Wallez <[email protected]>
---

diff --git a/src/dawn/native/CommandBufferStateTracker.cpp b/src/dawn/native/CommandBufferStateTracker.cpp
index ee1bc43..0d4ebc4 100644
--- a/src/dawn/native/CommandBufferStateTracker.cpp
+++ b/src/dawn/native/CommandBufferStateTracker.cpp
@@ -811,6 +811,7 @@
     mIndexFormat = format;
     mIndexBufferSize = size;
     mIndexBufferOffset = offset;
+    mAspects.reset(VALIDATION_ASPECT_INDEX_BUFFER);
 }
 
 void CommandBufferStateTracker::UnsetVertexBuffer(VertexBufferSlot slot) {
diff --git a/src/dawn/tests/unittests/validation/IndexBufferValidationTests.cpp b/src/dawn/tests/unittests/validation/IndexBufferValidationTests.cpp
index 203a63f..1942bb5 100644
--- a/src/dawn/tests/unittests/validation/IndexBufferValidationTests.cpp
+++ b/src/dawn/tests/unittests/validation/IndexBufferValidationTests.cpp
@@ -240,6 +240,43 @@
     }
 }
 
+// Check that changing the index buffer format forces new validation against the strip pipeline.
+TEST_F(IndexBufferValidationTest, IndexFormatChangesAfterFirstValidDraw) {
+    wgpu::RenderPipeline pipeline =
+        MakeTestPipeline(wgpu::IndexFormat::Uint32, wgpu::PrimitiveTopology::TriangleStrip);
+
+    wgpu::Buffer indexBuffer =
+        utils::CreateBufferFromData<uint32_t>(device, wgpu::BufferUsage::Index, {0, 1, 2});
+
+    utils::ComboRenderBundleEncoderDescriptor renderBundleDesc = {};
+    renderBundleDesc.colorFormatCount = 1;
+    renderBundleDesc.cColorFormats[0] = wgpu::TextureFormat::RGBA8Unorm;
+
+    // Control case: the strip index format matches the pipeline, then set again after a draw with
+    // the same format.
+    {
+        wgpu::RenderBundleEncoder encoder = device.CreateRenderBundleEncoder(&renderBundleDesc);
+        encoder.SetPipeline(pipeline);
+        encoder.SetIndexBuffer(indexBuffer, wgpu::IndexFormat::Uint32);
+        encoder.DrawIndexed(3);
+        encoder.SetIndexBuffer(indexBuffer, wgpu::IndexFormat::Uint32);
+        encoder.DrawIndexed(3);
+        encoder.Finish();
+    }
+
+    // Error case: the strip index format matches the pipeline, then set again after a draw with the
+    // different format this time.
+    {
+        wgpu::RenderBundleEncoder encoder = device.CreateRenderBundleEncoder(&renderBundleDesc);
+        encoder.SetPipeline(pipeline);
+        encoder.SetIndexBuffer(indexBuffer, wgpu::IndexFormat::Uint32);
+        encoder.DrawIndexed(3);
+        encoder.SetIndexBuffer(indexBuffer, wgpu::IndexFormat::Uint16);
+        encoder.DrawIndexed(3);
+        ASSERT_DEVICE_ERROR(encoder.Finish());
+    }
+}
+
 // Check that the index buffer must have the Index usage.
 TEST_F(IndexBufferValidationTest, InvalidUsage) {
     wgpu::Buffer indexBuffer =

diff --git a/src/dawn/tests/unittests/validation/IndexBufferValidationTests.cpp b/src/dawn/tests/unittests/validation/IndexBufferValidationTests.cpp
index 203a63f..1942bb5 100644
--- a/src/dawn/tests/unittests/validation/IndexBufferValidationTests.cpp
+++ b/src/dawn/tests/unittests/validation/IndexBufferValidationTests.cpp
@@ -240,6 +240,43 @@
     }
 }
 
+// Check that changing the index buffer format forces new validation against the strip pipeline.
+TEST_F(IndexBufferValidationTest, IndexFormatChangesAfterFirstValidDraw) {
+    wgpu::RenderPipeline pipeline =
+        MakeTestPipeline(wgpu::IndexFormat::Uint32, wgpu::PrimitiveTopology::TriangleStrip);
+
+    wgpu::Buffer indexBuffer =
+        utils::CreateBufferFromData<uint32_t>(device, wgpu::BufferUsage::Index, {0, 1, 2});
+
+    utils::ComboRenderBundleEncoderDescriptor renderBundleDesc = {};
+    renderBundleDesc.colorFormatCount = 1;
+    renderBundleDesc.cColorFormats[0] = wgpu::TextureFormat::RGBA8Unorm;
+
+    // Control case: the strip index format matches the pipeline, then set again after a draw with
+    // the same format.
+    {
+        wgpu::RenderBundleEncoder encoder = device.CreateRenderBundleEncoder(&renderBundleDesc);
+        encoder.SetPipeline(pipeline);
+        encoder.SetIndexBuffer(indexBuffer, wgpu::IndexFormat::Uint32);
+        encoder.DrawIndexed(3);
+        encoder.SetIndexBuffer(indexBuffer, wgpu::IndexFormat::Uint32);
+        encoder.DrawIndexed(3);
+        encoder.Finish();
+    }
+
+    // Error case: the strip index format matches the pipeline, then set again after a draw with the
+    // different format this time.
+    {
+        wgpu::RenderBundleEncoder encoder = device.CreateRenderBundleEncoder(&renderBundleDesc);
+        encoder.SetPipeline(pipeline);
+        encoder.SetIndexBuffer(indexBuffer, wgpu::IndexFormat::Uint32);
+        encoder.DrawIndexed(3);
+        encoder.SetIndexBuffer(indexBuffer, wgpu::IndexFormat::Uint16);
+        encoder.DrawIndexed(3);
+        ASSERT_DEVICE_ERROR(encoder.Finish());
+    }
+}
+
 // Check that the index buffer must have the Index usage.
 TEST_F(IndexBufferValidationTest, InvalidUsage) {
     wgpu::Buffer indexBuffer =