oetiker/rrdtool-1.x — pull request #384 by vincentbernat (2013-04-05 14:09:46+00:00)
Title: graph: allow RRD files to be missing

An option (-Z/--missing-ds) is added to allow RRD files to be
missing. In this case, the unknown value is assumed.

This is a proposition to solve issue #377.