view mercurial/hgweb/wsgicgi.py @ 12998:91cb08a9e7fb

discovery: list new remote heads in prepush() on --debug

With this patch applied, Mercurial will list the hashes of new remote heads
if push --debug aborts because of new remote heads (option -f/--force not set).

Example:

  $ hg push --debug repo1
  using http://example.org/repo1
  http auth: user johndoe, password not set
  sending between command
  pushing to http://example.org/repo1
  sending capabilities command
  capabilities: changegroupsubset stream=1 lookup pushkey unbundle=HG10GZ,HG10BZ,HG10UN branchmap
  sending heads command
  searching for changes
  common changesets up to 609edbc7853f
  sending branchmap command
  new remote heads on branch 'default'        <- new output line
  new remote head 5862c07f53a2                <- new output line
  abort: push creates new remote heads on branch 'default'!
  (did you forget to merge? use push -f to force)

Compare to without --debug (not changed by this patch, including it here
for reference purposes only):

  $ hg push repo1
  pushing to http://example.org/repo1
  searching for changes
  abort: push creates new remote heads on branch 'default'!
  (did you forget to merge? use push -f to force)

Motivation for this change:

'hg outgoing' may list a whole lot of benign changesets plus an odd changeset
that will trigger the "new remote heads" abort. It can be hard to spot that
single unwanted changeset (it may be an old forgotten experiment, lingering
in the local repo).

"hg log -r 'heads(outgoing())'" might be useful, but that also lists a head
that may be benign on push.

Inside prepush(), we already know which heads are causing troubles on 'hg push'.
Why not make that info available (at least on --debug)?

This would also be helpful for doing remote support, as the supporter can ask
the user to paste the output of 'hg push --debug' on error and then ask further
questions about the heads listed.

# hgweb/wsgicgi.py - CGI->WSGI translator
#
# Copyright 2006 Eric Hopper <[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.
#
# This was originally copied from the public domain code at
# http://www.python.org/dev/peps/pep-0333/#the-server-gateway-side

import os, sys
from mercurial import util

def launch(application):
    util.set_binary(sys.stdin)
    util.set_binary(sys.stdout)

    environ = dict(os.environ.iteritems())
    environ.setdefault('PATH_INFO', '')
    if environ.get('SERVER_SOFTWARE', '').startswith('Microsoft-IIS'):
        # IIS includes script_name in path_info
        scriptname = environ['SCRIPT_NAME']
        if environ['PATH_INFO'].startswith(scriptname):
            environ['PATH_INFO'] = environ['PATH_INFO'][len(scriptname):]

    environ['wsgi.input'] = sys.stdin
    environ['wsgi.errors'] = sys.stderr
    environ['wsgi.version'] = (1, 0)
    environ['wsgi.multithread'] = False
    environ['wsgi.multiprocess'] = True
    environ['wsgi.run_once'] = True

    if environ.get('HTTPS', 'off').lower() in ('on', '1', 'yes'):
        environ['wsgi.url_scheme'] = 'https'
    else:
        environ['wsgi.url_scheme'] = 'http'

    headers_set = []
    headers_sent = []
    out = sys.stdout

    def write(data):
        if not headers_set:
            raise AssertionError("write() before start_response()")

        elif not headers_sent:
            # Before the first output, send the stored headers
            status, response_headers = headers_sent[:] = headers_set
            out.write('Status: %s\r\n' % status)
            for header in response_headers:
                out.write('%s: %s\r\n' % header)
            out.write('\r\n')

        out.write(data)
        out.flush()

    def start_response(status, response_headers, exc_info=None):
        if exc_info:
            try:
                if headers_sent:
                    # Re-raise original exception if headers sent
                    raise exc_info[0](exc_info[1], exc_info[2])
            finally:
                exc_info = None     # avoid dangling circular ref
        elif headers_set:
            raise AssertionError("Headers already set!")

        headers_set[:] = [status, response_headers]
        return write

    content = application(environ, start_response)
    try:
        for chunk in content:
            write(chunk)
    finally:
        if hasattr(content, 'close'):
            content.close()