[#134 state:fixed] Removing all dupes from the results sets it in 'not modified' state.

core/results.py

@@ -272,7 +272,7 @@ class Results(Markable):
         for group in affected_groups:
             group.discard_matches()
         self.__dupes = None
-        self.is_modified = True
+        self.is_modified = bool(self.__groups)
     
     def save_to_xml(self, outfile):
         self.apply_filter(None)

core/tests/results_test.py

@@ -225,6 +225,12 @@ class TestCaseResultsWithSomeGroups:
         self.results.load_from_xml(f, get_file)
         assert not self.results.is_modified
     
+    def test_is_modified_after_removing_all_results(self):
+        # Removing all results sets the is_modified flag to false.
+        self.results.mark_all()
+        self.results.perform_on_marked(lambda x:None, True)
+        assert not self.results.is_modified
+    
 
 class TestCaseResultsWithSavedResults:
     def setup_method(self, method):