Add a note about httpexceptions and generator applications (#242)

1 files changed, 4 insertions, 0 deletions

diff --git a/paste/httpexceptions.py b/paste/httpexceptions.py
index cd3b81a..b14ad5a 100644
--- a/paste/httpexceptions.py
+++ b/paste/httpexceptions.py
@@ -616,6 +616,10 @@ class HTTPExceptionHandler(object):
     ``HTTPException``) and turns them into proper HTTP responses.
     Note if the headers have already been sent, the stack trace is
     always maintained as this indicates a programming error.
+
+    Note that you must raise the exception before returning the
+    app_iter, and you cannot use this with generator apps that don't
+    raise an exception until after their app_iter is iterated over.
     """
 
     def __init__(self, application, warning_level=None):