Add `egg:Zope2#httpexceptions` WSGI middleware, refs #64.

This serves the same purpose as `egg:paste#httpexceptions`, but
recognizes exceptions derived from `zExceptions.HTTPException`.

CHANGES.rst

@@ -51,6 +51,8 @@ Bugs Fixed
 Features Added
 ++++++++++++++
 
+- Add `egg:Zope2#httpexceptions` WSGI middleware.
+
 - Update available HTTP response code, 302 is now called Found.
 
 - Add a new `runwsgi` script to serve PasteDeploy files.

setup.py

@@ -122,6 +122,9 @@ setup(
         'paste.app_factory': [
             'main=Zope2.Startup.run:make_wsgi_app',
         ],
+        'paste.filter_app_factory': [
+            'httpexceptions=Zope2.Startup.httpexceptions:main',
+        ],
         'console_scripts': [
             'mkzopeinstance=Zope2.utilities.mkzopeinstance:main',
             'runwsgi=Zope2.Startup.serve:main',

src/Zope2/Startup/httpexceptions.py

+from zExceptions import HTTPException
+
+
+class HTTPExceptionHandler(object):
+
+    def __init__(self, application):
+        self.application = application
+
+    def __call__(self, environ, start_response):
+        environ['Zope2.httpexceptions'] = self
+        try:
+            return self.application(environ, start_response)
+        except HTTPException as exc:
+            return exc(environ, start_response)
+
+
+def main(app, global_conf=None):
+    return HTTPExceptionHandler(app)

src/Zope2/utilities/skel/etc/zope.ini.in

@@ -4,7 +4,7 @@ zope_conf = %(here)s/wsgi.conf
 
 [pipeline:main]
 pipeline =
-    egg:paste#httpexceptions
+    egg:Zope2#httpexceptions
     egg:repoze.retry#retry
     egg:repoze.tm2#tm
     zope