Comment 3 for bug 1045464

This feature has been implemented by Tavmjong Bah in core Inkscape in rev 14980 and a few follow-up commits (14983, 15007).

* Optionally sort attributes and properties into a canonical order.
  Useful for comparing different versions of an SVG file.
https://bazaar.launchpad.net/~inkscape.dev/inkscape/trunk/revision/14980

The new SVG output feature is controlled by a preference setting (which has no GUI yet in the preferences dialog), and is disabled by default. The attribute "sort_attributes" of the group "svgoutput" in preferences.xml controls the output ('0' to disable (default), '1' to enable).