ipython/ipython — pull request #1130 by minrk (2011-12-08 23:51:03+00:00)
Title: don't allow arg_split to raise shlex's ValueError

Sometimes we pass things that aren't really command-line args to arg_split, e.g:

%timeit python_code(" ")

These things probably shouldn't be parsed as command-line args, but they are.
So we should at least prevent them from raising, when shlex doesn't think they are valid shell args.

This commit protects this sort of thing from raising errors. Another
approach would be to use a different function when parsing things that
are clearly not command-line args (like Python code), but this works for now.

closes #1109