- Don't call HTTPExceptions that are looked up in TemplateDicts

CHANGES.rst

@@ -4,7 +4,10 @@ Changelog
 3.1 (unreleased)
 ----------------
 
-- Nothing changed yet.
+Bug fixes
++++++++++
+
+- Don't call HTTPExceptions that are looked up in TemplateDicts
 
 
 3.0 (2019-05-09)

src/DocumentTemplate/_DocumentTemplate.py

@@ -107,6 +107,7 @@
 
 from Acquisition import aq_base
 from ExtensionClass import Base
+from zExceptions import HTTPException
 
 from DocumentTemplate.html_quote import html_quote
 from DocumentTemplate.ustr import ustr
@@ -393,7 +394,7 @@ def getitem(self, key, call=0):
                     return e.__render_with_namespace__(self)
 
                 base = aq_base(e)
-                if safe_callable(base):
+                if safe_callable(base) and not isinstance(base, HTTPException):
                     if getattr(base, 'isDocTemp', False):
                         return e(None, self)
                     return e()

src/DocumentTemplate/tests/test_templatedict.py

@@ -141,6 +141,19 @@ def test_callable_namespace(self):
         td._push({'one': DummyNamespace('one')})
         self.assertEqual(td['one'], ('namespace', 'one', (td, )))
 
+    def test_callable_httpexception(self):
+        # Subclasses of zException.HTTPException are callable but should
+        # not be called during lookup in the template dict.
+        from zExceptions import NotFound
+        from zExceptions import Unauthorized
+
+        notfound = NotFound('ouch')
+        unauth = Unauthorized('argh')
+        td = TemplateDict()
+        td._push({'one': unauth, 'two': notfound})
+        self.assertEqual(td['one'], unauth)
+        self.assertEqual(td['two'], notfound)
+
 
 class TestRestrictedTemplateDict(unittest.TestCase):
     # Based on tests for Products.PageTemplates.ZRPythonExpr.