URLs to load codemirror contains double slashes which fail the load

All the Javascript resources are loaded with a URL similar to:
http://localhost:8080/xwiki/webjars/codemirror/5.8//lib/codemirror.js

This is a Jetty/HSQLDB XWiki 7.4.2 instance. Has been tested on:

• Firefox Developer Edition (47.0a2 (2016-03-25))
• Chromium (49.0.2623.108)

One possible fix is to modify a line in SyntaxHighlighting.SyntaxHighlighting, in the JavascriptExtension object. The line to change is

SyntaxHighlighting_cm : codeMirrorWebjarHome

into

SyntaxHighlighting_cm : codeMirrorWebjarHome.substr(0, codeMirrorWebjarHome.length - 1)