hgweb: support custom http headers in ErrorResponse

mercurial/hgweb/common.py

@@ -17,9 +17,10 b' HTTP_METHOD_NOT_ALLOWED = 405'
 HTTP_SERVER_ERROR = 500
 
 class ErrorResponse(Exception):
-    def __init__(self, code, message=None):
+    def __init__(self, code, message=None, headers=[]):
         Exception.__init__(self)
         self.code = code
+        self.headers = headers
         if message is not None:
             self.message = message
         else:

mercurial/hgweb/request.py

@@ -77,6 +77,7 b' class wsgirequest(object):'
 
             if isinstance(status, ErrorResponse):
                 status = statusmessage(status.code)
+                self.header(status.headers)
             elif status == 200:
                 status = '200 Script output follows'
             elif isinstance(status, int):