tests/test-doctest.py

smtp: verify the certificate of the SMTP server for STARTTLS/SMTPS

Before this patch, the certificate of the SMTP server for STARTTLS or
SMTPS isn't verified.

This may cause man-in-the-middle security problem (stealing
authentication information), even though SMTP channel itself is
encrypted by SSL.

When "[smtp] tls" is configured as "smtps" or "starttls", this patch:

  - uses classes introduced by preceding patches instead of "SMTP" or
    "SMTP_SSL" of smtplib, and

  - verifies the certificate of the SMTP server, if "[smtp]
    verifycert" is configured as other than False

"[smtp] verifycert" can be configured in 3 levels:

  - "strict":

    This verifies peer certificate, and aborts if:

      - peer certification is not valid, or
      - no configuration in "[hostfingerprints]" and "[web] cacerts"

    This is default value of "[smtp] verifycert" for security.

  - "loose":

    This verifies peer certificate, and aborts if peer certification is
    not valid.

    This just shows warning message ("certificate not verified"), if
    there is no configuration in "[hostfingerprints]" and "[web]
    cacerts".

    This is as same as verification for HTTPS connection.

  - False(no verification):

    Peer certificate is not verified.

    This is as same as the behavior before this patch series.

"hg email --insecure" uses "loose" level, and ignores "[web] cacerts"
as same as push/pull/etc... with --insecure.

Ignoring "[web] cacerts" configuration for "hg email --insecure" is
already done in "dispatch._dispatch()" by looking "insecure" up in the
table of command options.

# this is hack to make sure no escape characters are inserted into the output
import os
if 'TERM' in os.environ:
    del os.environ['TERM']
import doctest

import mercurial.util
doctest.testmod(mercurial.util)
# Only run doctests for the current platform
doctest.testmod(mercurial.util.platform)

import mercurial.changelog
doctest.testmod(mercurial.changelog)

import mercurial.dagparser
doctest.testmod(mercurial.dagparser, optionflags=doctest.NORMALIZE_WHITESPACE)

import mercurial.match
doctest.testmod(mercurial.match)

import mercurial.store
doctest.testmod(mercurial.store)

import mercurial.ui
doctest.testmod(mercurial.ui)

import mercurial.url
doctest.testmod(mercurial.url)

import mercurial.encoding
doctest.testmod(mercurial.encoding)

import mercurial.hgweb.hgwebdir_mod
doctest.testmod(mercurial.hgweb.hgwebdir_mod)

import hgext.convert.cvsps
doctest.testmod(hgext.convert.cvsps)

import mercurial.revset
doctest.testmod(mercurial.revset)

import mercurial.minirst
doctest.testmod(mercurial.minirst)

import mercurial.templatefilters
doctest.testmod(mercurial.templatefilters)