Added support for generic HTTPException handlers on app and blueprints

Error handlers are now returned in order of blueprint:code, app:code,
blueprint:HTTPException, app:HTTPException, None

Corresponding tests also added.

Ref issue #941, pr #1383, #2082, #2144

tests/test_user_error_handler.py

@@ -1,5 +1,10 @@
 # -*- coding: utf-8 -*-
-from werkzeug.exceptions import Forbidden, InternalServerError, HTTPException, NotFound
+from werkzeug.exceptions import (
+    Forbidden,
+    InternalServerError,
+    HTTPException,
+    NotFound
+    )
 import flask
 
 
@@ -32,29 +37,6 @@ def test_error_handler_no_match():
     assert c.get('/keyerror').data == b'KeyError'
 
 
-def test_default_error_handler():
-    app = flask.Flask(__name__)
-
-    @app.errorhandler(HTTPException)
-    def catchall_errorhandler(e):
-        assert isinstance(e, HTTPException)
-        assert isinstance(e, NotFound)
-        return 'default'
-
-    @app.errorhandler(Forbidden)
-    def catchall_errorhandler(e):
-        assert isinstance(e, Forbidden)
-        return 'forbidden'
-
-    @app.route('/forbidden')
-    def forbidden():
-        raise Forbidden()
-
-    c = app.test_client()
-    assert c.get('/undefined').data == b'default'
-    assert c.get('/forbidden').data == b'forbidden'
-
-
 def test_error_handler_subclass():
     app = flask.Flask(__name__)
 
@@ -161,3 +143,53 @@ def test_error_handler_blueprint():
 
     assert c.get('/error').data == b'app-error'
     assert c.get('/bp/error').data == b'bp-error'
+
+
+def test_default_error_handler():
+    bp = flask.Blueprint('bp', __name__)
+
+    @bp.errorhandler(HTTPException)
+    def bp_exception_handler(e):
+        assert isinstance(e, HTTPException)
+        assert isinstance(e, NotFound)
+        return 'bp-default'
+
+    @bp.errorhandler(Forbidden)
+    def bp_exception_handler(e):
+        assert isinstance(e, Forbidden)
+        return 'bp-forbidden'
+
+    @bp.route('/undefined')
+    def bp_registered_test():
+        raise NotFound()
+
+    @bp.route('/forbidden')
+    def bp_forbidden_test():
+        raise Forbidden()
+
+    app = flask.Flask(__name__)
+
+    @app.errorhandler(HTTPException)
+    def catchall_errorhandler(e):
+        assert isinstance(e, HTTPException)
+        assert isinstance(e, NotFound)
+        return 'default'
+
+    @app.errorhandler(Forbidden)
+    def catchall_errorhandler(e):
+        assert isinstance(e, Forbidden)
+        return 'forbidden'
+
+    @app.route('/forbidden')
+    def forbidden():
+        raise Forbidden()
+
+    app.register_blueprint(bp, url_prefix='/bp')
+
+    c = app.test_client()
+    assert c.get('/bp/undefined').data == b'bp-default'
+    assert c.get('/bp/forbidden').data == b'bp-forbidden'
+    assert c.get('/undefined').data == b'default'
+    assert c.get('/forbidden').data == b'forbidden'
+
+