Bug 210105 – Serious WebAssembly breakage in Safari 13

• Status: RESOLVED
• Resolution: DUPLICATE
• Component: JavaScriptCore

[Alessandro Pignotti]

Created attachment 395671 [details]
Font rendering corrupted

The issue can be reproduced on the following page: https://cheerpjdemos.leaningtech.com/SwingDemo.html#demo

Font rendering is based on WebAssembly, and renders correctly in Safari 12.1 and all the other browsers. With Safari 13 and a local build of WebKitGtk the rendering is corrupted, see attached image.

We have received multiple bug reports caused by Safari 13 on our WebAssembly based products, we believe there may be a serious miscompilation problem.

[Tadeu Zagallo]

Thanks for filing the bug. Which revision did you test with locally? I could reproduce it with STP, but not with my local build. I think this might have already been fixed by https://trac.webkit.org/r258965, can you confirm whether it still reproduces for you after that?

[Alessandro Pignotti]

I tested locally with WekKitGTK 2.28, built from this archive https://webkitgtk.org/releases/webkitgtk-2.28.0.tar.xz

[Tadeu Zagallo]

From looking at https://svn.webkit.org/repository/webkit/releases/WebKitGTK/webkit-2.28.0/Source/JavaScriptCore/ChangeLog, it seems like that change is not included in WebKitGTK 2.28.0. If you want to double check, you could build trunk from source. Otherwise I'll go ahead and dupe this to https://bugs.webkit.org/show_bug.cgi?id=209333, as it seems to fix the issue when testing on mac.

[Alessandro Pignotti]

I confirm that https://trac.webkit.org/r258965 fixes the problem

[Radar WebKit Bug Importer]

<rdar://problem/61411915>

[Tadeu Zagallo]

Thanks for confirming!

*** This bug has been marked as a duplicate of bug 209333 ***