Test out-of-bounds writes in glCopyTexSubImage2D

src/libANGLE/renderer/vulkan/TextureVk.cpp

@@ -368,12 +368,6 @@ angle::Result TextureVk::copySubImageImpl(const gl::Context *context,
     // If negative offsets are given, clippedSourceArea ensures we don't read from those offsets.
     // However, that changes the sourceOffset->destOffset mapping.  Here, destOffset is shifted by
     // the same amount as clipped to correct the error.
-    //
-    // TODO(syoussefi): a bug here is that we need to clip the extents to make sure the copy
-    // region does not overflow the image size.  For example, if an FBO of size 16x16 is used as
-    // source and glCopyTexImage2D(..., -8, -8, 16, 16, ...) is used, then we will be copying to
-    // the region expanding from (8, 8) through (23, 23), while the image is only 16x16.
-    // http://anglebug.com/3355
     const gl::Offset modifiedDestOffset(destOffset.x + clippedSourceArea.x - sourceArea.x,
                                         destOffset.y + clippedSourceArea.y - sourceArea.y, 0);
 

src/tests/gl_tests/CopyTexImageTest.cpp

@@ -162,6 +162,10 @@ class CopyTexImageTest : public ANGLETest
         glCopyTexSubImage2D(GL_TEXTURE_2D, 0, 1, 1, 0, 0, kFboSizes[0], kFboSizes[0]);
         ASSERT_GL_ERROR(GL_INVALID_VALUE);
 
+        // xoffset + width > w and yoffset + height > h, out of bounds
+        glCopyTexSubImage2D(GL_TEXTURE_2D, 0, 0, 0, -1, -1, 1 + kFboSizes[0], 1 + kFboSizes[0]);
+        ASSERT_GL_ERROR(GL_INVALID_VALUE);
+
         // Copy the second fbo over a portion of the image.
         GLint offset = kFboSizes[0] / 2;
         GLint extent = kFboSizes[0] - offset;