Bug 210105

Summary: Serious WebAssembly breakage in Safari 13
Product: WebKit Reporter: Alessandro Pignotti <alessandro>
Component: JavaScriptCoreAssignee: Nobody <webkit-unassigned>
Status: RESOLVED DUPLICATE    
Severity: Major CC: alessandro, tzagallo, webkit-bug-importer
Priority: P2 Keywords: InRadar
Version: Safari 13   
Hardware: PC   
OS: All   
Attachments:
Description Flags
Font rendering corrupted none

Description Alessandro Pignotti 2020-04-07 05:01:52 PDT 
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.
Comment 1 Tadeu Zagallo 2020-04-07 08:28:07 PDT 
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?
Comment 2 Alessandro Pignotti 2020-04-07 08:32:34 PDT 
I tested locally with WekKitGTK 2.28, built from this archive https://webkitgtk.org/releases/webkitgtk-2.28.0.tar.xz
Comment 3 Tadeu Zagallo 2020-04-07 08:45:54 PDT 
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.
Comment 4 Alessandro Pignotti 2020-04-07 14:56:15 PDT 
I confirm that https://trac.webkit.org/r258965 fixes the problem
Comment 5 Radar WebKit Bug Importer 2020-04-07 14:57:15 PDT 
<rdar://problem/61411915>
Comment 6 Tadeu Zagallo 2020-04-07 14:57:55 PDT 
Thanks for confirming!

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