record: get rid of ui.backupconfig

import: get rid of ui.backupconfig

clone: get rid of ui.backupconfig

commit: get rid of ui.backupconfig

branchmap: handle nullrev in setcachedata 906be86990 recently changed to switch from: self._rbcrevs[rbcrevidx:rbcrevidx + _rbcrecsize] = rec to pack_into(_rbcrecfmt, self._rbcrevs, rbcrevidx, node, branchidx) This causes an exception if rbcrevidx is -1 (i.e. the nullrev). The old code handled this because python handles out of bound sets to arrays gracefully. The new code throws because the self._rbcrevs buffer isn't long enough to write 8 bytes to. Normally it would've been resized by the immediately preceding line, but because the 0 length buffer is greater than the idx (-1) times the size, no resize happens. Setting the branch for the nullrev doesn't make sense anyway, so let's skip it. This was caught by external tests in the Facebook extensions repo, but I've added a test here that catches the issue.

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.