context: explicitly tests for None Changeset 9e57033fec0c removed the mutable default value, but did not explicitly tested for None. Such implicit testing can introduce semantic and performance issue. We move to an explicit testing for None as recommended by PEP8: https://www.python.org/dev/peps/pep-0008/#programming-recommendations

filemerge: explicitly tests for None Changeset 758526333dec removed the mutable default value, but did not explicitly tested for None. Such implicit testing can introduce semantic and performance issue. We move to an explicit testing for None as recommended by PEP8: https://www.python.org/dev/peps/pep-0008/#programming-recommendations

hgweb: explicitly tests for None Changeset 7dafa8d0e006 removed the mutable default value, but did not explicitly tested for None. Such implicit testing can introduce semantic and performance issue. We move to an explicit testing for None as recommended by PEP8: https://www.python.org/dev/peps/pep-0008/#programming-recommendations

hgweb: explicitly tests for None in webutil Changeset d2878bec55bd removed the mutable default value, but did not explicitly tested for None. Such implicit testing can introduce semantic and performance issue. We move to an explicit testing for None as recommended by PEP8: https://www.python.org/dev/peps/pep-0008/#programming-recommendations

match: explicitly tests for None Changeset 6168d4b93634 removed the mutable default value, but did not explicitly tested for None. Such implicit testing can introduce semantic and performance issue. We move to an explicit testing for None as recommended by PEP8: https://www.python.org/dev/peps/pep-0008/#programming-recommendations

mq: explicitly tests for None Changeset fd3d8eb7f545 removed the mutable default value, but did not explicitly tested for None. Such implicit testing can introduce semantic and performance issue. We move to an explicit testing for None as recommended by PEP8: https://www.python.org/dev/peps/pep-0008/#programming-recommendations

rebase: explicitly tests for None Changeset 361bccce566a removed the mutable default value, but did not explicitly tested for None. Such implicit checking can introduce semantic and performance issue. We move to an explicit check for None as recommended by PEP8: https://www.python.org/dev/peps/pep-0008/#programming-recommendations

py3: use iter() instead of iterkeys()