gpu: bound overlapping image copies by both native backings

src/graphics/host_gpu/renderer/image/image.cpp

@@ -353,8 +353,12 @@ void Image::CopyImage(Image& source) {
 	std::vector<vk::ImageCopy> copies;
 	copies.reserve(levels);
 	for (uint32_t level = 0; level < levels; level++) {
-		const auto width  = std::max(source.backing.extent.width >> level, 1u);
-		const auto height = std::max(source.backing.extent.height >> level, 1u);
+		// Overlapping cache images can differ in size; copying the source extent into a smaller
+		// destination writes out of bounds and loses the device.
+		const auto width  = std::min(std::max(source.backing.extent.width >> level, 1u),
+		                             std::max(backing.extent.width >> level, 1u));
+		const auto height = std::min(std::max(source.backing.extent.height >> level, 1u),
+		                             std::max(backing.extent.height >> level, 1u));
 		const auto depth  = std::max(base_depth >> level, 1u);
 		const auto [source_layers, destination_layers] = SanitizeCopyLayers(source, *this, depth);
 		vk::ImageCopy copy {};