Correct second-last timestamp

changedetectionio/model/Watch.py

@@ -279,6 +279,10 @@ class model(dict):
 
         for k in sorted_keys:
             if int(k) < int(last_viewed):
+                if prev_k == sorted_keys[0]:
+                    # Return the second last one so we dont recommend the same version compares itself
+                    return sorted_keys[1]
+
                 return prev_k
             prev_k = k
 

changedetectionio/tests/unit/test_watch_model.py

@@ -23,9 +23,16 @@ class TestDiffBuilder(unittest.TestCase):
         watch.save_history_text(contents=b"hello world", timestamp=109, snapshot_id=str(uuid_builder.uuid4()))
         watch.save_history_text(contents=b"hello world", timestamp=112, snapshot_id=str(uuid_builder.uuid4()))
         watch.save_history_text(contents=b"hello world", timestamp=115, snapshot_id=str(uuid_builder.uuid4()))
+        watch.save_history_text(contents=b"hello world", timestamp=117, snapshot_id=str(uuid_builder.uuid4()))
 
         p = watch.get_next_snapshot_key_to_last_viewed
         assert p == "112", "Correct last-viewed timestamp was detected"
 
+        # When there is only one step of difference from the end of the list, it should return second-last change
+        watch['last_viewed'] = 116
+        p = watch.get_next_snapshot_key_to_last_viewed
+        assert p == "115", "Correct 'second last' last-viewed timestamp was detected when using the last timestamp"
+
+
 if __name__ == '__main__':
     unittest.main()