Bug 250662

Summary:	CreatePattern for zero height image should return null
Product:	WebKit	Reporter:	Karl Dubost <karlcow>
Component:	Canvas	Assignee:	Anne van Kesteren <annevk>
Status:	RESOLVED FIXED
Severity:	Normal	CC:	dino, webkit-bug-importer
Priority:	P2	Keywords:	BrowserCompat, InRadar, WPTImpact
Version:	Safari Technology Preview
Hardware:	Unspecified
OS:	Unspecified
See Also:	https://bugs.webkit.org/show_bug.cgi?id=93344 https://bugs.webkit.org/show_bug.cgi?id=226964

Description Karl Dubost 2023-01-15 19:27:52 PST

The first two steps of createPattern(img, repetition)

> 1. Let usability be the result of checking the usability of image.
> 2. If usability is bad, then return null.
— https://html.spec.whatwg.org/multipage/canvas.html#dom-context-2d-createpattern-dev

The usability of the image is assessed as: 

> If image has an intrinsic width or intrinsic height (or both) equal to zero, then return bad.
https://html.spec.whatwg.org/multipage/canvas.html#check-the-usability-of-the-image-argument


The WPT test fails in Safari TP 161 while it pass in both firefox and chrome.
http://wpt.live/html/canvas/element/fill-and-stroke-styles/2d.pattern.image.zeroheight.html
https://wpt.fyi/results/html/canvas/element/fill-and-stroke-styles/2d.pattern.image.zeroheight.html

The code currently doesn't check the height of the image.
https://searchfox.org/wubkat/rev/18e40f7108b3aa25f33242319e32278e08e25e44/Source/WebCore/html/canvas/CanvasRenderingContext2DBase.cpp#1984-2015

Comment 1 Radar WebKit Bug Importer 2023-01-15 19:28:03 PST

<rdar://problem/104285727>

Comment 2 Anne van Kesteren 2023-08-26 09:39:24 PDT

Pull request: https://github.com/WebKit/WebKit/pull/17107

Comment 3 EWS 2023-08-27 01:47:15 PDT

Committed 267334@main (94656d3143fa): <https://commits.webkit.org/267334@main>

Reviewed commits have been landed. Closing PR #17107 and removing active labels.