Bug 262192 – A GitHub project page with embedded SVG takes an extremely long time to load

• Status: RESOLVED
• Resolution: CONFIGURATION CHANGED
• Component: SVG

Website: https://github.com/facebookincubator/below

The website takes a long time to load, the page hangs. Navigating to sub-links is also slow. This is a WebKit specific behavior, the website loads fine on Chrome. I also tried disabling all the extensions but this looks like a bug with WebKit.

[Alexey Proskuryakov]

Thsnk you for the report! As this is reported against Safari 17, do you happen to know if this was happening with Safari 16.x before?

It's taking time under LegacyRenderSVGRoot::layout -> SVGTextMetricsBuilder::walkTree -> WebCore::Font::applyTransforms.

Thanks for the prompt response. Yes, this was happening in Safari 16.x as well.
I had reported this for Safari 16 using Feedback Assistant but I should have known better.

[Simon Fraser (smfr)]

Lots of time under:
     2404 WebCore::RenderBlockFlow::layoutBlockChildren(bool, WebCore::LayoutUnit&)  (in WebCore) + 4960  [0x61767b2b0]
       2404 WebCore::LegacyRenderSVGRoot::layout()  (in WebCore) + 1094  [0x6178bfe86]
         2404 WebCore::SVGRenderSupport::layoutChildren(WebCore::RenderElement&, bool)  (in WebCore) + 706  [0x6178a03d2]
           2404 WebCore::LegacyRenderSVGContainer::layout()  (in WebCore) + 269  [0x6178b5a6d]
             2404 WebCore::SVGRenderSupport::layoutChildren(WebCore::RenderElement&, bool)  (in WebCore) + 706  [0x6178a03d2]
               2402 WebCore::RenderSVGText::layout()  (in WebCore) + 1309  [0x61558439d]
               ! 2398 WebCore::SVGTextMetricsBuilder::walkTree(WebCore::RenderElement&, WebCore::RenderSVGInlineText*, WebCore::MeasureTextData*)  (in WebCore) + 127  [0x6178b3b4f]
               ! : 2329 WebCore::SVGTextMetricsBuilder::walkTree(WebCore::RenderElement&, WebCore::RenderSVGInlineText*, WebCore::MeasureTextData*)  (in WebCore) + 127  [0x6178b3b4f]
               ! : | 2279 WebCore::SVGTextMetricsBuilder::walkTree(WebCore::RenderElement&, WebCore::RenderSVGInlineText*, WebCore::MeasureTextData*)  (in WebCore) + 92  [0x6178b3b2c]
               ! : | + 1997 WebCore::SVGTextMetricsBuilder::measureTextRenderer(WebCore::RenderSVGInlineText&, WebCore::MeasureTextData*)  (in WebCore) + 1358  [0x6178b31ce]
               ! : | + ! 1404 WebCore::WidthIterator::advance(unsigned int, WebCore::GlyphBuffer&)  (in WebCore) + 188  [0x6174737cc]
               ! : | + ! : 1098 WebCore::WidthIterator::advanceInternal<WebCore::Latin1TextIterator>(WebCore::Latin1TextIterator&, WebCore::GlyphBuffer&)  (in WebCore) + 4011  [0x617474c7b]
               ! : | + ! : | 1054 WebCore::WidthIterator::commitCurrentFontRange(WebCore::AdvanceInternalState&)  (in WebCore) + 963  [0x6174722d3]

[Radar WebKit Bug Importer]

<rdar://problem/116188712>

[Ahmad Saleem]

One potential merge: https://src.chromium.org/viewvc/blink?view=revision&revision=168005

> Eliminate recursion in SVGTextMetricsBuilder::walkTree

[Ahmad Saleem]

I think it is fixed on WebKit ToT (270133@main).

Is there a way to verify this, maybe in Safari TP? I am not sure which commit fixed it, so cannot check in release notes.

[Ahmad Saleem]

(In reply to cueball045 from comment #7)
> Is there a way to verify this, maybe in Safari TP? I am not sure which
> commit fixed it, so cannot check in release notes.

I think it might be fixed because of following commit:

https://commits.webkit.org/270110@main

Which is not in Safari Technology Preview. It might be in STP183 or STP184 or even STP185.

That's super helpful. Thanks a lot!

[Ryosuke Niwa]

Yeah, this appears to be fixed on trunk.