Created attachment 344960 [details]
Test file containing a gradient with both x2="100%" and gradientUnits="userSpaceOnUse"

Note: I hope this is the correct place to report this. eog, GIMP and the preview/thumbnail in Nautilus all display the behavior described here, but I couldn’t find definite information on whether they both use librsvg.

The SVG standard <https://www.w3.org/TR/SVG11/pservers.html#LinearGradientElementX1Attribute> specifies that the default value of the “x2” attribute on gradient elements is “100%” and that omitting the attribute is equivalent to specifying x2="100%". However, if  gradientUnits="userSpaceOnUse" is also set, the SVG image displays differently depending on whether the x2 attribute is omitted or explicitly set to 100%.

Steps to Reproduce:
1) Display both attached sample SVG files (x2_set.svg and x2_unset.svg) using e.g. eog or GIMP and observe the output.

Actual Results: The displayed images are different (x2_set.svg shows a gradient which is red to green from left to right, while x2_unset.svg looks like a solid green rectangle).

Expected Results: Both images should look the same.

Build Date & Hardware: Version 2.40.13-3 of the librsvg2-2 package from the Ubuntu repositories (<https://launchpad.net/ubuntu/xenial/+source/librsvg>) on Ubuntu 16.04.1.