view contrib/showstack.py @ 31060:ab20491b1760

dispatch: rearrange 'unknown command' code to better employ pager

dispatch calls help like a ninja if you give it a truly unknown
command, and that might want to be paged. If it gets paged, then the
'hg: unknown command' text gets eaten by a grue, unless we call the
pager first. This change rearranges the codepaths so we can safely
only invoke the pager in the case where we'll have long output from
the help command code, rather than just a short message like "did you
mean stat instead of start" or "fetch is provided by the fetch
extension".

# 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