tests/test-hgweb-no-request-uri.t

rust-re2: add wrapper for calling Re2 from Rust

This assumes that Re2 is installed following Google's guide. I am not sure
how we want to integrate it in the project, but I think a follow-up patch would
be more appropriate for such work.
As it stands, *not* having Re2 installed results in a compilation error, which
is a problem as it breaks install compatibility. Hence, this is gated behind
a non-default `with-re2` compilation feature.

Differential Revision: https://phab.mercurial-scm.org/D7910

This tests if hgweb and hgwebdir still work if the REQUEST_URI variable is
no longer passed with the request. Instead, SCRIPT_NAME and PATH_INFO
should be used from d74fc8dec2b4 onward to route the request.

  $ hg init repo
  $ cd repo
  $ echo foo > bar
  $ hg add bar
  $ hg commit -m "test"
  $ hg tip
  changeset:   0:61c9426e69fe
  tag:         tip
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     test
  
  $ cat > request.py <<EOF
  > from __future__ import absolute_import
  > import os
  > import sys
  > from mercurial import (
  >     encoding,
  >     hgweb,
  >     util,
  > )
  > stringio = util.stringio
  > 
  > errors = stringio()
  > input = stringio()
  > 
  > def startrsp(status, headers):
  >     print('---- STATUS')
  >     print(status)
  >     print('---- HEADERS')
  >     print([i for i in headers if i[0] != 'ETag'])
  >     print('---- DATA')
  >     return output.write
  > 
  > env = {
  >     'wsgi.version': (1, 0),
  >     'wsgi.url_scheme': 'http',
  >     'wsgi.errors': errors,
  >     'wsgi.input': input,
  >     'wsgi.multithread': False,
  >     'wsgi.multiprocess': False,
  >     'wsgi.run_once': False,
  >     'REQUEST_METHOD': 'GET',
  >     'SCRIPT_NAME': '',
  >     'SERVER_NAME': '$LOCALIP',
  >     'SERVER_PORT': os.environ['HGPORT'],
  >     'SERVER_PROTOCOL': 'HTTP/1.0'
  > }
  > 
  > def process(app):
  >     content = app(env, startrsp)
  >     sys.stdout.write(encoding.strfromlocal(output.getvalue()))
  >     sys.stdout.write(encoding.strfromlocal(b''.join(content)))
  >     getattr(content, 'close', lambda : None)()
  >     print('---- ERRORS')
  >     print(encoding.strfromlocal(errors.getvalue())) # avoid b'' output diff
  > 
  > output = stringio()
  > env['PATH_INFO'] = '/'
  > env['QUERY_STRING'] = 'style=atom'
  > process(hgweb.hgweb(b'.', name=b'repo'))
  > 
  > output = stringio()
  > env['PATH_INFO'] = '/file/tip/'
  > env['QUERY_STRING'] = 'style=raw'
  > process(hgweb.hgweb(b'.', name=b'repo'))
  > 
  > output = stringio()
  > env['PATH_INFO'] = '/'
  > env['QUERY_STRING'] = 'style=raw'
  > process(hgweb.hgwebdir({b'repo': b'.'}))
  > 
  > output = stringio()
  > env['PATH_INFO'] = '/repo/file/tip/'
  > env['QUERY_STRING'] = 'style=raw'
  > process(hgweb.hgwebdir({b'repo': b'.'}))
  > EOF
  $ "$PYTHON" request.py
  ---- STATUS
  200 Script output follows
  ---- HEADERS
  [('Content-Type', 'application/atom+xml; charset=ascii')]
  ---- DATA
  <?xml version="1.0" encoding="ascii"?>
  <feed xmlns="http://www.w3.org/2005/Atom">
   <!-- Changelog -->
   <id>http://$LOCALIP:$HGPORT/</id> (glob)
   <link rel="self" href="http://$LOCALIP:$HGPORT/atom-log"/> (glob)
   <link rel="alternate" href="http://$LOCALIP:$HGPORT/"/> (glob)
   <title>repo Changelog</title>
   <updated>1970-01-01T00:00:00+00:00</updated>
  
   <entry>
    <title>[default] test</title>
    <id>http://$LOCALIP:$HGPORT/#changeset-61c9426e69fef294feed5e2bbfc97d39944a5b1c</id> (glob)
    <link href="http://$LOCALIP:$HGPORT/rev/61c9426e69fe"/> (glob)
    <author>
     <name>test</name>
     <email>&#116;&#101;&#115;&#116;</email>
    </author>
    <updated>1970-01-01T00:00:00+00:00</updated>
    <published>1970-01-01T00:00:00+00:00</published>
    <content type="xhtml">
     <table xmlns="http://www.w3.org/1999/xhtml">
      <tr>
       <th style="text-align:left;">changeset</th>
       <td>61c9426e69fe</td>
      </tr>
      <tr>
       <th style="text-align:left;">branch</th>
       <td>default</td>
      </tr>
      <tr>
       <th style="text-align:left;">bookmark</th>
       <td></td>
      </tr>
      <tr>
       <th style="text-align:left;">tag</th>
       <td>tip</td>
      </tr>
      <tr>
       <th style="text-align:left;">user</th>
       <td>&#116;&#101;&#115;&#116;</td>
      </tr>
      <tr>
       <th style="text-align:left;vertical-align:top;">description</th>
       <td>test</td>
      </tr>
      <tr>
       <th style="text-align:left;vertical-align:top;">files</th>
       <td>bar<br /></td>
      </tr>
     </table>
    </content>
   </entry>
  
  </feed>
  ---- ERRORS
  
  ---- STATUS
  200 Script output follows
  ---- HEADERS
  [('Content-Type', 'text/plain; charset=ascii')]
  ---- DATA
  
  -rw-r--r-- 4 bar
  
  
  ---- ERRORS
  
  ---- STATUS
  200 Script output follows
  ---- HEADERS
  [('Content-Type', 'text/plain; charset=ascii')]
  ---- DATA
  
  /repo/
  
  ---- ERRORS
  
  ---- STATUS
  200 Script output follows
  ---- HEADERS
  [('Content-Type', 'text/plain; charset=ascii')]
  ---- DATA
  
  -rw-r--r-- 4 bar
  
  
  ---- ERRORS
  

  $ cd ..