ipython/ipython — pull request #2783 by takluyver (2013-01-13 18:57:37+00:00)
Title: Prefilter shouldn't touch execution_count

Having gone through the various things that can call it, I'm pretty sure that there's no need for prefilter to be modifying the execution/prompt counter. And in testing, I can't construct an example that hits this bit of code.

If we agree on this, it supersedes #2623.