UserAgent: Mozilla/5.0 (Windows NT 10.0; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/57.0.2987.98 Safari/537.36

Steps to reproduce the problem:
1. Create a CSS background using the shorthand notation with a hex color and an image with a relative URL. (everything OK)

2. Change the color value from the hex value to something provided by a CSS variable. (image no longer renders)

3. Example: https://jsfiddle.net/nqgxgyj0/

What is the expected behavior?
The expected behaviour is that the rendering is the same no matter if the color is defined like a static hex value or read from a CSS variable.

What went wrong?
The image no longer renders.
Changing the URL to an absolute path fixes the problem.

Did this work before? N/A 

Does this work in other browsers? Yes

Chrome version: 57.0.2987.98  Channel: stable
OS Version: 10.0
Flash Version: 

See a basic fiddle that demonstrates the issue:
https://jsfiddle.net/nqgxgyj0/
 

Deleted: fiddle.txt 30 bytes

fiddle.txt 30 bytes View Download