contrib/showstack.py

obsolete: allow multiple predecessors in createmarkers

The logic for this change is similar to the change to `cleanupnodes` that we
did earlier. Now that the rebase code is trying to record a fold, we need to
actually record it in the markers. The first step is to have the markers
creation API able to receive such fold data.

To keep things sane, we restrict fold to on successors.

# showstack.py - extension to dump a Python stack trace on signal
#
# binds to both SIGQUIT (Ctrl-\) and SIGINFO (Ctrl-T on BSDs)
"""dump stack trace when receiving 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