Fixed issue with inproper handling of diff parsing that could lead to infinit loops. This was an edge case when diff contained diff data inside. Regresion test was added
"""Various utilities to work with Python < 2.7.Those utilities may be deleted once ``vcs`` stops support for older Pythonversions."""importsysifsys.version_info>=(2,7):unittest=__import__('unittest')else:unittest=__import__('unittest2')