Bug 143471

Summary:	[GTK] Layout Test canvas/philip/tests/2d.drawImage.animated.poster.html is failing
Product:	WebKit	Reporter:	Marcos Chavarría Teijeiro (irc: chavaone) <chavarria1991>
Component:	Tools / Tests	Assignee:	Nobody <webkit-unassigned>
Status:	NEW ---
Severity:	Normal	CC:	bugs-noreply, cgarcia, chavarria1991, maxstepin
Priority:	P2
Version:	528+ (Nightly build)
Hardware:	Unspecified
OS:	Unspecified

Description Marcos Chavarría Teijeiro (irc: chavaone) 2015-04-07 02:53:48 PDT

The canvas/philip/tests/2d.drawImage.animated.poster.html layout test is failing on GTK+ after r181553 (https://trac.webkit.org/changeset/181553).

This revision implements APNG support.

The diff is the following:

--- /home/ch01/jhbuild/src/WebKit/WebKitBuild/Release/layout-test-results/canvas/philip/tests/2d.drawImage.animated.poster-expected.txt
+++ /home/ch01/jhbuild/src/WebKit/WebKitBuild/Release/layout-test-results/canvas/philip/tests/2d.drawImage.animated.poster-actual.txt
@@ -1,2 +1,2 @@ 
-Passed
+Failed assertion: got pixel [255,0,0,255] at (50,25), expected [0,255,0,255] +/- 2

Comment 1 Max Stepin 2015-04-09 02:01:36 PDT

According to APNG specs, the first frame can be marked hidden.

This test:
Frame 0: green (hidden)
Frame 1: red

This test assumes canvas drawImage() is sophisticated enough be able to return hidden apng frame (green).

Instead the image decoders in both Firefox and WebKit prefer not to keep the useless hidden frame in memory, so both return the first *visible* frame.

You can see Firefox draws red frame too:
http://w3c-test.org/2dcontext/drawing-images-to-the-canvas/2d.drawImage.animated.poster.html

So I think we should simply mark this test accordingly.