contrib/showstack.py

context: follow all branches in blockdescendants()

In the initial implementation of blockdescendants (and thus followlines(...,
descend=True) revset), only the first branch encountered in descending
direction was followed.

Update the algorithm so that all children of a revision ('x' in code) are
considered. Accordingly, we need to prevent a child revision to be yielded
multiple times when it gets visited through different path, so we skip 'i'
when this occurs. Finally, since we now consider all parents of a possible
child touching a given line range, we take care of yielding the child if it
has a diff in specified line range with at least one of its parent (same logic
as blockancestors()).

# 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