tests/logexceptions.py

templater: handle None returned from templatedir()

My recent 91aa9bba3dc9 (templater: make templatepaths() return a
single path, or None, 2020-07-21) didn't account for the fact that
`templatedir()` returns `None` in frozen binaries. That is ironic,
since the reason I'm working on this is to add support for built-in
mapfiles in frozen binaries. This patch updates the callers to handle
the `None` case. It's somewhat ugly, but I will have to revisit this
soon anyway, since my goal is to make all callers handle that case by
trying to read the map file using the resources API instead.

Differential Revision: https://phab.mercurial-scm.org/D8810

# logexceptions.py - Write files containing info about Mercurial exceptions
#
# Copyright 2017 Matt Mackall <[e-mail]>
#
# This software may be used and distributed according to the terms of the
# GNU General Public License version 2 or any later version.

from __future__ import absolute_import

import inspect
import os
import sys
import traceback
import uuid

from mercurial import (
    dispatch,
    extensions,
)


def handleexception(orig, ui):
    res = orig(ui)

    if not ui.environ.get(b'HGEXCEPTIONSDIR'):
        return res

    dest = os.path.join(
        ui.environ[b'HGEXCEPTIONSDIR'], str(uuid.uuid4()).encode('ascii')
    )

    exc_type, exc_value, exc_tb = sys.exc_info()

    stack = []
    tb = exc_tb
    while tb:
        stack.append(tb)
        tb = tb.tb_next
    stack.reverse()

    hgframe = 'unknown'
    hgline = 'unknown'

    # Find the first Mercurial frame in the stack.
    for tb in stack:
        mod = inspect.getmodule(tb)
        if not mod.__name__.startswith(('hg', 'mercurial')):
            continue

        frame = tb.tb_frame

        try:
            with open(inspect.getsourcefile(tb), 'r') as fh:
                hgline = fh.readlines()[frame.f_lineno - 1].strip()
        except (IndexError, OSError):
            pass

        hgframe = '%s:%d' % (frame.f_code.co_filename, frame.f_lineno)
        break

    primary = traceback.extract_tb(exc_tb)[-1]
    primaryframe = '%s:%d' % (primary.filename, primary.lineno)

    with open(dest, 'wb') as fh:
        parts = [
            str(exc_value),
            primaryframe,
            hgframe,
            hgline,
            ui.environ[b'TESTNAME'].decode('utf-8', 'replace'),
        ]
        fh.write(b'\0'.join(p.encode('utf-8', 'replace') for p in parts))


def extsetup(ui):
    extensions.wrapfunction(dispatch, 'handlecommandexception', handleexception)