Handle negated streams in ok_to_include_history.

(imported from commit 0a049364e1d14f45db9f8e9aa5392039a01231eb)

zerver/test_messages.py

@@ -38,6 +38,12 @@ class IncludeHistoryTest(AuthedTestCase):
         realm = get_realm('zulip.com')
         create_stream_if_needed(realm, 'public_stream')
 
+        # Negated stream searches should not include history.
+        narrow = [
+            dict(operator='stream', operand='public_stream', negated=True),
+        ]
+        self.assertFalse(ok_to_include_history(narrow, realm))
+
         # Definitely forbid seeing history on private streams.
         narrow = [
             dict(operator='stream', operand='private_stream'),

zerver/views/messages.py

@@ -349,7 +349,7 @@ def ok_to_include_history(narrow, realm):
     include_history = False
     if narrow is not None:
         for term in narrow:
-            if term['operator'] == "stream":
+            if term['operator'] == "stream" and not term.get('negated', False):
                 if is_public_stream(term['operand'], realm):
                     include_history = True
         # Disable historical messages if the user is narrowing on anything