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.
from __future__ import absolute_import, print_function
import os
from mercurial import (
dispatch,
ui as uimod,
)
# ensure errors aren't buffered
testui = uimod.ui()
testui.pushbuffer()
testui.write(('buffered\n'))
testui.warn(('warning\n'))
testui.write_err('error\n')
print(repr(testui.popbuffer()))
# test dispatch.dispatch with the same ui object
hgrc = open(os.environ["HGRCPATH"], 'w')
hgrc.write('[extensions]\n')
hgrc.write('color=\n')
hgrc.close()
ui_ = uimod.ui.load()
ui_.setconfig('ui', 'formatted', 'True')
# we're not interested in the output, so write that to devnull
ui_.fout = open(os.devnull, 'w')
# call some arbitrary command just so we go through
# color's wrapped _runcommand twice.
def runcmd():
dispatch.dispatch(dispatch.request(['version', '-q'], ui_))
runcmd()
print("colored? %s" % (ui_._colormode is not None))
runcmd()
print("colored? %s" % (ui_._colormode is not None))