py3: call codecs.escape_encode() directly string_escape doesn't exist on Python 3, but fortunately the undocumented codecs.escape_encode() function exists on CPython 2.6, 2.7, 3.5 and PyPy 5.6. So let's use it for now. http://stackoverflow.com/a/23151714

templatekw: make join() escape values of extras (BC) (issue5504) Since extras may contain blob, the default template escapes its values: 'extra': '{key}={value|stringescape}' join() should follow the output style of the default template.

util: wrap s.encode('string_escape') call for future py3 compatibility

py3: prove hg tip works

py3: call strftime() with native str type Since strftime() may contain non-ascii character if locale set, we use strfrom/tolocal(). Now "hg tip" works.

encoding: add converter between native str and byte string This kind of encoding conversion is unavoidable on Python 3.

encoding: factor out unicode variants of from/tolocal() Unfortunately, these functions will be commonly used on Python 3.

py3: use next() to obtain next item from inner generator of generatorset .next attribute does not exist on Python 3. As this function seems to really care about the overhead of the Python interpreter, I follow the way of micro optimization.

py3: rewrite itervalues() as values() by importer I'm not a great fan of these importer magics, but this should be okay since "itervalues" seems as unique name as "iteritems".

py3: use portable way to stringify cache key of repoview

exewrapper: prefer HackableMercurial python if availbale Currently hg.exe will only try to load python27.dll from hg-python subdir if PYTHONHOME environment variable is not set. I think that it is better to check whether 'hg-python' subdir exists and load python from it in that case, regardless of environment. This allows for reliable approach of distributing Mercurial with its own Python.

import-checkers: split tests of the tool from running it on the source We did such splits for other tools already. The 'test-check-*.t' performs the check of the source code while the regular tests verifies the tools works. One of the benefit is that is provides a simple file to reuse in third party extensions.

py3: use bytestr wrapper in revsetlang.tokenize() This backs out 77270ec0cdd9 and wraps program by bytestr() instead.

py3: use bytestr wrapper in revsetlang.formatspec() This backs out 1c48a8278b2f and wraps expr by bytestr() instead.

pycompat: add bytestr wrapper which mostly acts as a Python 2 str This allows us to handle bytes in mostly the same manner as Python 2 str, so we can get rid of ugly s[i:i + 1] hacks: s = bytestr(s) while i < len(s): c = s[i] ... This is the simpler version of the previous RFC patch which tried to preserve the bytestr type if possible. New version simply drops the bytestr wrapping so we aren't likely to pass a bytestr to a function that expects Python 3 bytes.

tests: allow running doctests selectively on Python 3 Currently most doctests fail on Python 3, but I want to add some.

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()

localrepo: deprecated '_link' That method had a total on 1 internal user... G: changed mercurial/localrepo.py

localrepo: use self.wvfs.islink directly We are about to deprecate the helper function.

py3: convert opts back to bytes for status

parsers: handle refcounting of "parents" consistently Py_None can be refcounted like any other Python object. So do that.

py3: make py3 compat.iterbytestr simpler and faster With Python 3.4.3, timit says 11.9 usec-> 6.44 usec. With Python 3.6.0, timeit says 14.1 usec -> 9.55 usec.

py3: optimize py3 compat.bytechr using Struct.pack With Python 3.4.3, timeit says 0.437 usec -> 0.0685 usec. With Python 3.6, timeit says 0.157 usec -> 0.0907 usec. So it's faster on both versions, but the speedup varies a lot. Thanks to Gregory Szorc for the suggestion.