[GTK][WPE] Random incorrect image displayed as the background of a div

https://bugs.webkit.org/show_bug.cgi?id=265990

Reviewed by Žan Doberšek.

Add an unique ID to cairo surfaces created in ImageBackingStoreCairo. This unique ID allows us
to differentiate when the cairo surface that's backing an image has changed, so we are sure that
we're not using an incorrect value cached inside some ImageBackingStore.

* Source/WebCore/platform/graphics/cairo/CairoUtilities.cpp:
(WebCore::attachSurfaceUniqueID):
(WebCore::getSurfaceUniqueID):
* Source/WebCore/platform/graphics/cairo/CairoUtilities.h:
* Source/WebCore/platform/graphics/texmap/coordinated/CoordinatedGraphicsLayer.cpp:
(WebCore::CoordinatedGraphicsLayer::flushCompositingStateForThisLayerOnly):
* Source/WebCore/platform/image-decoders/cairo/ImageBackingStoreCairo.cpp:
(WebCore::ImageBackingStore::image const):

Canonical link: https://commits.webkit.org/272009@main

Author: magomez

Source/WebCore/platform/graphics/cairo/CairoUtilities.cpp

@@ -39,6 +39,7 @@
 #include "RefPtrCairo.h"
 #include "Region.h"
 #include <wtf/Assertions.h>
+#include <wtf/Atomics.h>
 #include <wtf/NeverDestroyed.h>
 #include <wtf/UniqueArray.h>
 #include <wtf/Vector.h>
@@ -53,6 +54,9 @@
 
 namespace WebCore {
 
+static cairo_user_data_key_t s_surfaceUniqueIDKey;
+static Atomic<uintptr_t> s_surfaceUniqueID = 1;
+
 #if USE(FREETYPE)
 RecursiveLock& cairoFontLock()
 {
@@ -381,6 +385,16 @@ cairo_matrix_t toCairoMatrix(const AffineTransform& transform)
     return cairo_matrix_t { transform.a(), transform.b(), transform.c(), transform.d(), transform.e(), transform.f() };
 }
 
+void attachSurfaceUniqueID(cairo_surface_t* surface)
+{
+    cairo_surface_set_user_data(surface, &s_surfaceUniqueIDKey, reinterpret_cast<void*>(s_surfaceUniqueID.exchangeAdd(1)), nullptr);
+}
+
+uintptr_t getSurfaceUniqueID(cairo_surface_t* surface)
+{
+    return reinterpret_cast<uintptr_t>(cairo_surface_get_user_data(surface, &s_surfaceUniqueIDKey));
+}
+
 } // namespace WebCore
 
 #endif // USE(CAIRO)

Source/WebCore/platform/graphics/cairo/CairoUtilities.h

@@ -99,6 +99,9 @@ RefPtr<cairo_region_t> toCairoRegion(const Region&);
 
 cairo_matrix_t toCairoMatrix(const AffineTransform&);
 
+void attachSurfaceUniqueID(cairo_surface_t*);
+uintptr_t getSurfaceUniqueID(cairo_surface_t*);
+
 } // namespace WebCore
 
 #endif // USE(CAIRO)

Source/WebCore/platform/graphics/texmap/coordinated/CoordinatedGraphicsLayer.cpp

@@ -26,6 +26,7 @@
 
 #if USE(COORDINATED_GRAPHICS)
 
+#include "CairoUtilities.h"
 #include "FloatQuad.h"
 #include "GraphicsContext.h"
 #include "GraphicsLayer.h"
@@ -908,7 +909,7 @@ void CoordinatedGraphicsLayer::flushCompositingStateForThisLayerOnly()
         ASSERT(m_compositedImage);
         auto& image = *m_compositedImage;
         uintptr_t imageID = reinterpret_cast<uintptr_t>(&image);
-        uintptr_t nativeImageID = reinterpret_cast<uintptr_t>(m_compositedNativeImage->platformImage().get());
+        uintptr_t nativeImageID = getSurfaceUniqueID(m_compositedNativeImage->platformImage().get());
 
         // Respawn the ImageBacking object if the underlying image changed.
         if (m_nicosia.imageBacking) {
@@ -928,7 +929,7 @@ void CoordinatedGraphicsLayer::flushCompositingStateForThisLayerOnly()
         auto& layerState = impl.layerState();
         layerState.imageID = imageID;
         layerState.update.isVisible = transformedVisibleRect().intersects(IntRect(contentsRect()));
-        if (layerState.update.isVisible && layerState.update.nativeImageID != nativeImageID) {
+        if (layerState.update.isVisible && (!nativeImageID || layerState.update.nativeImageID != nativeImageID)) {
             layerState.update.nativeImageID = nativeImageID;
             layerState.update.imageBackingStore = m_coordinator->imageBackingStore(nativeImageID,
                 [&] {

Source/WebCore/platform/image-decoders/cairo/ImageBackingStoreCairo.cpp

@@ -24,6 +24,7 @@
  */
 
 #include "config.h"
+#include "CairoUtilities.h"
 #include "ImageBackingStore.h"
 
 #include <cairo.h>
@@ -41,6 +42,7 @@ PlatformImagePtr ImageBackingStore::image() const
         static_cast<DataSegment*>(data)->deref();
     });
 
+    attachSurfaceUniqueID(surface.get());
     return surface;
 }