Bug 187268

Summary:	[GTK] Layout test compositing/backing/backing-store-attachment-outside-viewport.html is failing
Product:	WebKit	Reporter:	Michael Catanzaro <mcatanzaro>
Component:	WebKitGTK	Assignee:	Nobody <webkit-unassigned>
Status:	NEW ---
Severity:	Normal	CC:	bugs-noreply, cadubentzen, calvaris, magomez, simon.fraser, zan
Priority:	P2
Version:	Other
Hardware:	PC
OS:	Linux
See Also:	https://bugs.webkit.org/show_bug.cgi?id=187994

Description Michael Catanzaro 2018-07-02 14:34:45 PDT

Layout test compositing/backing/backing-store-attachment-outside-viewport.html was added in r233268 "https://hackernoon.com/ uses lots of layer backing store" is failing for GTK with the following diff:

--- /home/slave/webkitgtk/gtk-linux-64-release-tests/build/layout-test-results/compositing/backing/backing-store-attachment-outside-viewport-expected.txt
+++ /home/slave/webkitgtk/gtk-linux-64-release-tests/build/layout-test-results/compositing/backing/backing-store-attachment-outside-viewport-actual.txt
@@ -18,13 +18,13 @@
           (position 8.00 1613.00)
           (bounds 600.00 600.00)
           (drawsContent 1)
-          (backingStoreAttached 0)
+          (backingStoreAttached 1)
         )
         (GraphicsLayer
           (position 8.00 3213.00)
           (bounds 600.00 600.00)
           (drawsContent 1)
-          (backingStoreAttached 0)
+          (backingStoreAttached 1)
         )
       )
     )

I don't know anything, but I assume that means we are using memory to hold content that is not drawn, so perhaps this is of interest to the graphics folks.

Comment 1 Simon Fraser (smfr) 2018-07-25 08:27:11 PDT

The "backing store attached" logic is in GraphicsLayerCA. I don't know how to detach backing store on the other platforms.