pyqtgraph/pyqtgraph — pull request #109 by nicolaisi (2014-10-16 10:29:03+00:00)
Title: fixed the Pen None property.

previously, setting "pen" to None will not have any effects on the output, this pull request will fix this.

- https://groups.google.com/forum/#!topic/pyqtgraph/t6cl1CevlB0

Signed-off-by: Nicholas Tan Jerome