hgweb: in protocol adapter, avoid control reaching end of non-void function

This greatly confounded some Python 3 porting work, once it was
managing to get this far.

Differential Revision: https://phab.mercurial-scm.org/D962

mercurial/hgweb/protocol.py

@@ -1,201 +1,203
 #
 # Copyright 21 May 2005 - (c) 2005 Jake Edge <[e-mail]>
 # Copyright 2005-2007 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 cgi
 import struct
 
 from .common import (
     HTTP_OK,
 )
 
 from .. import (
+    error,
     util,
     wireproto,
 )
 stringio = util.stringio
 
 urlerr = util.urlerr
 urlreq = util.urlreq
 
 HGTYPE = 'application/mercurial-0.1'
 HGTYPE2 = 'application/mercurial-0.2'
 HGERRTYPE = 'application/hg-error'
 
 def decodevaluefromheaders(req, headerprefix):
     """Decode a long value from multiple HTTP request headers."""
     chunks = []
     i = 1
     while True:
         v = req.env.get('HTTP_%s_%d' % (
             headerprefix.upper().replace('-', '_'), i))
         if v is None:
             break
         chunks.append(v)
         i += 1
 
     return ''.join(chunks)
 
 class webproto(wireproto.abstractserverproto):
     def __init__(self, req, ui):
         self.req = req
         self.response = ''
         self.ui = ui
         self.name = 'http'
 
     def getargs(self, args):
         knownargs = self._args()
         data = {}
         keys = args.split()
         for k in keys:
             if k == '*':
                 star = {}
                 for key in knownargs.keys():
                     if key != 'cmd' and key not in keys:
                         star[key] = knownargs[key][0]
                 data['*'] = star
             else:
                 data[k] = knownargs[k][0]
         return [data[k] for k in keys]
     def _args(self):
         args = self.req.form.copy()
         postlen = int(self.req.env.get('HTTP_X_HGARGS_POST', 0))
         if postlen:
             args.update(cgi.parse_qs(
                 self.req.read(postlen), keep_blank_values=True))
             return args
 
         argvalue = decodevaluefromheaders(self.req, 'X-HgArg')
         args.update(cgi.parse_qs(argvalue, keep_blank_values=True))
         return args
     def getfile(self, fp):
         length = int(self.req.env['CONTENT_LENGTH'])
         # If httppostargs is used, we need to read Content-Length
         # minus the amount that was consumed by args.
         length -= int(self.req.env.get('HTTP_X_HGARGS_POST', 0))
         for s in util.filechunkiter(self.req, limit=length):
             fp.write(s)
     def redirect(self):
         self.oldio = self.ui.fout, self.ui.ferr
         self.ui.ferr = self.ui.fout = stringio()
     def restore(self):
         val = self.ui.fout.getvalue()
         self.ui.ferr, self.ui.fout = self.oldio
         return val
 
     def _client(self):
         return 'remote:%s:%s:%s' % (
             self.req.env.get('wsgi.url_scheme') or 'http',
             urlreq.quote(self.req.env.get('REMOTE_HOST', '')),
             urlreq.quote(self.req.env.get('REMOTE_USER', '')))
 
     def responsetype(self, v1compressible=False):
         """Determine the appropriate response type and compression settings.
 
         The ``v1compressible`` argument states whether the response with
         application/mercurial-0.1 media types should be zlib compressed.
 
         Returns a tuple of (mediatype, compengine, engineopts).
         """
         # For now, if it isn't compressible in the old world, it's never
         # compressible. We can change this to send uncompressed 0.2 payloads
         # later.
         if not v1compressible:
             return HGTYPE, None, None
 
         # Determine the response media type and compression engine based
         # on the request parameters.
         protocaps = decodevaluefromheaders(self.req, 'X-HgProto').split(' ')
 
         if '0.2' in protocaps:
             # Default as defined by wire protocol spec.
             compformats = ['zlib', 'none']
             for cap in protocaps:
                 if cap.startswith('comp='):
                     compformats = cap[5:].split(',')
                     break
 
             # Now find an agreed upon compression format.
             for engine in wireproto.supportedcompengines(self.ui, self,
                                                          util.SERVERROLE):
                 if engine.wireprotosupport().name in compformats:
                     opts = {}
                     level = self.ui.configint('server',
                                               '%slevel' % engine.name())
                     if level is not None:
                         opts['level'] = level
 
                     return HGTYPE2, engine, opts
 
             # No mutually supported compression format. Fall back to the
             # legacy protocol.
 
         # Don't allow untrusted settings because disabling compression or
         # setting a very high compression level could lead to flooding
         # the server's network or CPU.
         opts = {'level': self.ui.configint('server', 'zliblevel')}
         return HGTYPE, util.compengines['zlib'], opts
 
 def iscmd(cmd):
     return cmd in wireproto.commands
 
 def call(repo, req, cmd):
     p = webproto(req, repo.ui)
 
     def genversion2(gen, compress, engine, engineopts):
         # application/mercurial-0.2 always sends a payload header
         # identifying the compression engine.
         name = engine.wireprotosupport().name
         assert 0 < len(name) < 256
         yield struct.pack('B', len(name))
         yield name
 
         if compress:
             for chunk in engine.compressstream(gen, opts=engineopts):
                 yield chunk
         else:
             for chunk in gen:
                 yield chunk
 
     rsp = wireproto.dispatch(repo, p, cmd)
     if isinstance(rsp, str):
         req.respond(HTTP_OK, HGTYPE, body=rsp)
         return []
     elif isinstance(rsp, wireproto.streamres):
         if rsp.reader:
             gen = iter(lambda: rsp.reader.read(32768), '')
         else:
             gen = rsp.gen
 
         # This code for compression should not be streamres specific. It
         # is here because we only compress streamres at the moment.
         mediatype, engine, engineopts = p.responsetype(rsp.v1compressible)
 
         if mediatype == HGTYPE and rsp.v1compressible:
             gen = engine.compressstream(gen, engineopts)
         elif mediatype == HGTYPE2:
             gen = genversion2(gen, rsp.v1compressible, engine, engineopts)
 
         req.respond(HTTP_OK, mediatype)
         return gen
     elif isinstance(rsp, wireproto.pushres):
         val = p.restore()
         rsp = '%d\n%s' % (rsp.res, val)
         req.respond(HTTP_OK, HGTYPE, body=rsp)
         return []
     elif isinstance(rsp, wireproto.pusherr):
         # drain the incoming bundle
         req.drain()
         p.restore()
         rsp = '0\n%s\n' % rsp.res
         req.respond(HTTP_OK, HGTYPE, body=rsp)
         return []
     elif isinstance(rsp, wireproto.ooberror):
         rsp = rsp.message
         req.respond(HTTP_OK, HGERRTYPE, body=rsp)
         return []
+    raise error.ProgrammingError('hgweb.protocol internal failure', rsp)