wireprotoserver: move error response handling out of hgweb

The exception handler for ErrorResponse has more to do with the
wire protocol than the generic HTTP server. Move the code so it
lives alongside other wire protocol code.

Differential Revision: https://phab.mercurial-scm.org/D2021

mercurial/hgweb/hgweb_mod.py

@@ -369,18 +369,7 b' class hgweb(object):'
                 if cmd in perms:
                     self.check_perm(rctx, req, perms[cmd])
             except ErrorResponse as inst:
-                # A client that sends unbundle without 100-continue will
-                # break if we respond early.
-                if (cmd == 'unbundle' and
-                    (req.env.get('HTTP_EXPECT',
-                                 '').lower() != '100-continue') or
-                    req.env.get('X-HgHttp2', '')):
-                    req.drain()
-                else:
-                    req.headers.append((r'Connection', r'Close'))
-                req.respond(inst, wireprotoserver.HGTYPE,
-                            body='0\n%s\n' % inst)
-                return ''
+                return protohandler['handleerror'](inst)
 
             return protohandler['dispatch']()
 

mercurial/wireprotoserver.py

@@ -242,6 +242,7 b' def parsehttprequest(repo, req, query):'
         'cmd': cmd,
         'proto': proto,
         'dispatch': lambda: _callhttp(repo, req, proto, cmd),
+        'handleerror': lambda ex: _handlehttperror(ex, req, cmd),
     }
 
 def _callhttp(repo, req, proto, cmd):
@@ -303,6 +304,22 b' def _callhttp(repo, req, proto, cmd):'
         return []
     raise error.ProgrammingError('hgweb.protocol internal failure', rsp)
 
+def _handlehttperror(e, req, cmd):
+    """Called when an ErrorResponse is raised during HTTP request processing."""
+    # A client that sends unbundle without 100-continue will
+    # break if we respond early.
+    if (cmd == 'unbundle' and
+        (req.env.get('HTTP_EXPECT',
+                     '').lower() != '100-continue') or
+        req.env.get('X-HgHttp2', '')):
+        req.drain()
+    else:
+        req.headers.append((r'Connection', r'Close'))
+
+    req.respond(e, HGTYPE, body='0\n%s\n' % e)
+
+    return ''
+
 class sshserver(abstractserverproto):
     def __init__(self, ui, repo):
         self._ui = ui