tests: demonstrate crash when trying to rebase merge without its parents
As the test case shows, when "hg rebase -d G -r 'B + D + F'" is run on
the following graph, we crash with traceback. It's reasonable to fail
because we can not easily produce a correct rebased F. The problem is
what diff to apply to either the rebased B or the rebased D. We could
potentially produce the result by e.g. applying the (F-D) diff to the
rebased B and then applying the reverse (E-D) diff on top, but that
could result in merge conflicts in each of those steps, which we don't
have a way of dealing with. So for now, let's just add a test case to
demonstrate that we crash (i.e. the AssertionError is clearly
incorrect since the user can run into it).
F
/|
C E
| |
B D G
\|/
A
Differential Revision: https://phab.mercurial-scm.org/D212
# showstack.py - extension to dump a Python stack trace on signal
#
# binds to both SIGQUIT (Ctrl-\) and SIGINFO (Ctrl-T on BSDs)
from __future__ import absolute_import
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 extsetup(ui):
signal.signal(signal.SIGQUIT, sigshow)
try:
signal.signal(signal.SIGINFO, sigshow)
except AttributeError:
pass