tests/test-config-env.py

convert: don't drop missing or corrupt tag entries

Cleaning up the tags file could be a useful feature in some cases, so maybe
there should be a switch for this.  However, the default hg -> hg convert tries
to maintain identical hashes (thus convert.hg.saverev is off by default, but is
on by default for other source types).  It looks like _rewritesubstate() has a
`continue` in it, and therefore a similar problem.

I ran into this conversion divergence when a coworker "merged" two repositories
by copy/pasting all of the files from the source repo and massaging the code,
and forgetting to revert the .hg* files.  That silently emptied the .hgtags file
after the conversion.  (This isn't the manifest node bug Yuya has been helping
with- this occurred well after the bzr -> hg conversion and wasn't a merge
commit, which made it extra puzzling.  That bug is still an issue.)

# Test the config layer generated by environment variables

from __future__ import absolute_import, print_function

import os

from mercurial import (
    encoding,
    rcutil,
    ui as uimod,
    util,
)

from mercurial.utils import (
    procutil,
)

testtmp = encoding.environ[b'TESTTMP']

# prepare hgrc files
def join(name):
    return os.path.join(testtmp, name)

with open(join(b'sysrc'), 'wb') as f:
    f.write(b'[ui]\neditor=e0\n[pager]\npager=p0\n')

with open(join(b'userrc'), 'wb') as f:
    f.write(b'[ui]\neditor=e1')

# replace rcpath functions so they point to the files above
def systemrcpath():
    return [join(b'sysrc')]

def userrcpath():
    return [join(b'userrc')]

rcutil.systemrcpath = systemrcpath
rcutil.userrcpath = userrcpath
os.path.isdir = lambda x: False # hack: do not load default.d/*.rc

# utility to print configs
def printconfigs(env):
    encoding.environ = env
    rcutil._rccomponents = None # reset cache
    ui = uimod.ui.load()
    for section, name, value in ui.walkconfig():
        source = ui.configsource(section, name)
        procutil.stdout.write(b'%s.%s=%s # %s\n'
                              % (section, name, value, util.pconvert(source)))
    procutil.stdout.write(b'\n')

# environment variable overrides
printconfigs({})
printconfigs({b'EDITOR': b'e2', b'PAGER': b'p2'})