diff --git a/mercurial/hgweb/hgweb_mod.py b/mercurial/hgweb/hgweb_mod.py
--- a/mercurial/hgweb/hgweb_mod.py
+++ b/mercurial/hgweb/hgweb_mod.py
@@ -82,28 +82,6 @@ class hgweb(object):
 
         self.refresh()
 
-        # process this if it's a protocol request
-        # protocol bits don't need to create any URLs
-        # and the clients always use the old URL structure
-
-        cmd = req.form.get('cmd', [''])[0]
-        if cmd and cmd in protocol.__all__:
-            try:
-                if cmd in perms:
-                    try:
-                        self.check_perm(req, perms[cmd])
-                    except ErrorResponse, inst:
-                        if cmd == 'unbundle':
-                            req.drain()
-                        raise
-                method = getattr(protocol, cmd)
-                return method(self.repo, req)
-            except ErrorResponse, inst:
-                req.respond(inst, protocol.HGTYPE)
-                if not inst.message:
-                    return []
-                return '0\n%s\n' % inst.message,
-
         # work with CGI variables to create coherent structure
         # use SCRIPT_NAME, PATH_INFO and QUERY_STRING as well as our REPO_NAME
 
@@ -123,6 +101,30 @@ class hgweb(object):
             query = req.env['QUERY_STRING'].split('&', 1)[0]
             query = query.split(';', 1)[0]
 
+        # process this if it's a protocol request
+        # protocol bits don't need to create any URLs
+        # and the clients always use the old URL structure
+
+        cmd = req.form.get('cmd', [''])[0]
+        if cmd and cmd in protocol.__all__:
+            if query:
+                raise ErrorResponse(HTTP_NOT_FOUND)
+            try:
+                if cmd in perms:
+                    try:
+                        self.check_perm(req, perms[cmd])
+                    except ErrorResponse, inst:
+                        if cmd == 'unbundle':
+                            req.drain()
+                        raise
+                method = getattr(protocol, cmd)
+                return method(self.repo, req)
+            except ErrorResponse, inst:
+                req.respond(inst, protocol.HGTYPE)
+                if not inst.message:
+                    return []
+                return '0\n%s\n' % inst.message,
+
         # translate user-visible url structure to internal structure
 
         args = query.split('/', 2)