gruntjs/grunt-contrib-less — pull request #98 by iki (2013-11-14 19:24:07+00:00)
Title: Use output file with .map extensing appended if sourceMapFilename==true.

Same functionality as in less if --sourcemap filename is omitted ... https://github.com/less/less.js/blob/master/lib/less/lessc_helper.js#L42

Esp. useful when generating multiple css files in single task, see `sourceMapFilenameDefault` test in `Gruntfile.js`.