contrib/showstack.py

bundle: allow bundlerepo to support alternative manifest implementations

With our treemanifest logic, the manifests are no longer transported as part of
the changegroup and are no longer stored in a revlog. This means the
self.manifestlog line in bundlerepo.filestart no longer calls
_constructmanifest, and therefore does not consume the manifest portion of the
changegroup, which means filestart is not populated and we result in an infinite
loop.

The fix is to make filestart aware that self.manifestlog might not consume the
changegroup part, and consume it manually if necessary.

There's currently no way to test this in core, but our treemanifest extension
has tests to cover this.

Differential Revision: https://phab.mercurial-scm.org/D1329

# 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