Bug 213788 – REGRESSION(r260276): Overflow scrolling layers misplaced inside SVG foreign object

• Status: RESOLVED
• Resolution: FIXED
• Component: SVG

[Muhammet Olcay]

Created attachment 403191 [details]
example view

you can see difference between UIWebView and WKWebView svg rendering difference

broken html code part is;

<foreignObject x="24" y="175" width="327" height="120">
    <textarea readonly="" xmlns="http://www.w3.org/1999/xhtml" placeholder="Placeholder text will be display here."></textarea>
</foreignObject>

I faced that problem only when use textarea element in svg objects and I tested all iphone devices which is support version of wkwebview.

regards

[Alexey Proskuryakov]

It looks like the WKWebView rendering is wrong. Can you reproduce this in Safari, and share the complete test case please?

[Muhammet Olcay]

Created attachment 403354 [details]
Example Html

[Muhammet Olcay]

Created attachment 403360 [details]
safari from simulator iphone 11

Hi Alexey,
I just added [https://bugs.webkit.org/attachment.cgi?id=403354] example html file for test case
Open that html file on mobile safari or wkwebview and you will face that problem instantly

[Alexey Proskuryakov]

I get a different yet result from Safari on iOS 14 beta on iPhone 11 Pro. And even though Mac Safari looks good, Mac WebKit2 MiniBrowser does not. In MiniBrowser, I see that the textarea is absolutely positioned, but the text moves as I resize the window.

My guess would be different viewport handling between WKWebView and UIWebView, but CC'ing some experts.

[Radar WebKit Bug Importer]

<rdar://problem/65039637>

[Simon Fraser (smfr)]

This is basically bug 23113.

[Simon Fraser (smfr)]

Created attachment 404042 [details]
Patch

[zalan]

Comment on attachment 404042 [details]
Patch

View in context: https://bugs.webkit.org/attachment.cgi?id=404042&action=review

> Source/WebCore/dom/Document.h:1275
> +    bool mayHaveRenderedSVGForeignObjects() const { return m_mayHaveRenderedSVGForeignObjects; }
> +    void setMayHaveRenderedSVGForeignObjects() { m_mayHaveRenderedSVGForeignObjects = true; }

It's a pity though that we set this bit on the Document and the only client is the RenderLayer (while we always have a top level layer).

[EWS]

Committed r264269: <https://trac.webkit.org/changeset/264269>

All reviewed patches have been landed. Closing bug and clearing flags on attachment 404042 [details].