[cairo] BackingStore::incorporateUpdate should use CompositeCopy to support drawsBack...
[WebKit-https.git] / Source / WebKit / ChangeLog
index f7599fb..959ee01 100644 (file)
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+2018-11-19  Tomoki Imai  <Tomoki.Imai@sony.com>
+
+        [cairo] BackingStore::incorporateUpdate should use CompositeCopy to support drawsBackground=false in general Cairo ports
+        https://bugs.webkit.org/show_bug.cgi?id=191577
+
+        Reviewed by Carlos Garcia Campos.
+
+        We should use CompositeCopy operator to update bitmap to overwrite existing bitmap even if source contains
+        transparent parts. It enables ports which uses Cairo to set drawsBackground to false.
+        GTK ports has custom background extension, and in such case, we need to use CompositeSourceOver to retain
+        custom background.
+
+        * UIProcess/cairo/BackingStoreCairo.cpp:
+        (WebKit::BackingStore::incorporateUpdate): Use CompositeCopy operator to update bitmap.
+
 2018-11-19  Joseph Pecoraro  <pecoraro@apple.com>
 
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