absorb: preserve changesets which were already empty
Most commands in Mercurial (commit, rebase, absorb itself) don’t create empty
changesets or drop them if they become empty. If there’s a changeset that’s
empty, it must be a deliberate choice of the user. At least it shouldn’t be
absorb’s responsibility to prune them. The fact that changesets that became
empty during absorb are pruned, is unaffected by this.
This case was found while writing patches which make it possible to configure
absorb and rebase to not drop empty changesets. Even without having such config
set, I think it’s valuable to preserve changesets which were already empty.
# showstack.py - extension to dump a Python stack trace on signal
#
# binds to both SIGQUIT (Ctrl-\) and SIGINFO (Ctrl-T on BSDs)
r"""dump stack trace when receiving SIGQUIT (Ctrl-\) or SIGINFO (Ctrl-T on BSDs)
"""
from __future__ import absolute_import, print_function
import signal
import sys
import traceback
def sigshow(*args):
sys.stderr.write("\n")
traceback.print_stack(args[1], limit=10, file=sys.stderr)
sys.stderr.write("----\n")
def sigexit(*args):
sigshow(*args)
print('alarm!')
sys.exit(1)
def extsetup(ui):
signal.signal(signal.SIGQUIT, sigshow)
signal.signal(signal.SIGALRM, sigexit)
try:
signal.signal(signal.SIGINFO, sigshow)
except AttributeError:
pass