Bug 150257 – SVG feBlend With in2 from a feImage result linking to an embedded SVG document rendered wrong

• Status: NEW
• Component: SVG

[Andres Gomez Garcia]

Created attachment 263332 [details]
Screenshot of the issue.

Reproduced with WebKitGTK+ 2.10.0 and with Safari 7.1 on OS X Mavericks.

Steps to reproduce the problem:
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Open the URL:
https://rawgit.com/tanty/design-hodgepodge/master/svg/filter/feBlend-feImage-tests.html


What is the expected behavior?
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All the SVGs are shown as the included PNG as reference


What went wrong?
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Only the SVGs in which the feImage provides explicit values for x=0, y=0, width=100% and height=100% are shown correctly.

The 2 SVGs in which this values are not provided for the feImage (the defaults are as explained above[1]) are not displayed properly.

Funnily enough, the render is yet different depending on whether the embedded SVG document provides a "viewBox" attribute.

If the viewBox is not explicit, the feImage shows proper proportions but the origin seems to be in the left top corner of the filter region[2] (x=-10%, y=-10%).

If the viewBox is explicit to the width and height values of the embedded SVG document (which, AFAIK, is the default), the proportions are also wrong.

[1] http://www.w3.org/TR/SVG/filters.html#FilterPrimitiveSubRegion
[2] http://www.w3.org/TR/SVG/filters.html#FilterEffectsRegion

[Andres Gomez Garcia]

Similar issues in other web engines:

* https://code.google.com/p/chromium/issues/detail?id=544172
* https://bugzilla.mozilla.org/show_bug.cgi?id=1215575
* https://github.com/MicrosoftEdge/Status/issues/308