Bug 77803 – SVG Tiny: 'non-scaling-stroke' incorrectly implemented in 'path' element

• Status: RESOLVED
• Resolution: WONTFIX
• Component: SVG

Setting 'vector-effect' property to 'non-scaling-stroke' in 'path' element does nothing unless 'stroke-width' is set to zero, this produces a 1 pixel wide stroke.  No other width is available.

This does not comply with the SVG standard, see-
http://www.w3.org/TR/SVGTiny12/painting.html#StrokeWidthProperty
and
http://www.w3.org/TR/SVGTiny12/painting.html#NonScalingStroke

The version affected is that installed in the latest releases of Chrome and Qt.

[Dirk Schulze]

(In reply to comment #0)
> Setting 'vector-effect' property to 'non-scaling-stroke' in 'path' element does nothing unless 'stroke-width' is set to zero, this produces a 1 pixel wide stroke.  No other width is available.

We have test cases for non-scaling-stroke which don't fail. But IIRC they just use rects as shapes. Can you test it with rects again and check if your test is working for rects? Also it would be great if you can provide a minimal test case that demonstrates the problem. Thanks.

Created attachment 126038 [details]
svg file to test 'non-scaling-stroke' in rect and path elements

Further testing has revealed that the problem is restricted to the Qt implementation of WebKit, it does not recognise the 'non-scaling-stroke' value of vector-effects unless the stroke-width is set to zero.
Chrome displays a 1 pixel line when the stroke-width is zero, which not what is recommended by the SVG standard.
I have included a testcase.

[Ahmad Saleem]

Comment 02 mentions that this bug was limited to Qt framework implementation of Webkit, which is no longer supported and all browser (Chrome Canary 105 and Firefox Nightly 104) matches with Safari 15.5 in attached test case. I think this can be marked as "RESOLVED INVALID" or "RESOLVED WONTFIX". In case, if I am testing incorrectly, please retest accordingly. Thanks!