Enforce same security flag in variant-based grouping (#5231)

b/494197991

Author: ViniciustCosta

src/clusterfuzz/_internal/cron/grouper.py

@@ -238,6 +238,11 @@ def _check_variant_grouping_candidate(testcase_1: TestcaseAttributes,
   if testcase_1.one_time_crasher_flag or testcase_2.one_time_crasher_flag:
     return
 
+  # Rule: Avoid grouping security and functional bugs, regardless of variants
+  # having the same security flag.
+  if testcase_1.security_flag != testcase_2.security_flag:
+    return
+
   # Rule: Group testcase with similar variants.
   # For each testcase2, get the related variant1 and check for equivalence.
   candidate_variant = data_handler.get_testcase_variant(testcase_1_id,

src/clusterfuzz/_internal/tests/appengine/handlers/cron/grouper_test.py

@@ -497,21 +497,25 @@ def test_similar_but_anomalous_variants_for_variant_analysis(self):
     self.testcases[2].project_name = 'project1'
     self.testcases[2].crash_type = 'crash_type3'
     self.testcases[2].crash_state = 'x2'
+    self.testcases[2].security_flag = True
 
     self.testcases.append(test_utils.create_generic_testcase())
     self.testcases[3].project_name = 'project1'
     self.testcases[3].crash_type = 'crash_type4'
     self.testcases[3].crash_state = 'y3'
+    self.testcases[3].security_flag = True
 
     self.testcases.append(test_utils.create_generic_testcase())
     self.testcases[4].project_name = 'project1'
     self.testcases[4].crash_type = 'crash_type5'
     self.testcases[4].crash_state = 'z4'
+    self.testcases[4].security_flag = True
 
     self.testcases.append(test_utils.create_generic_testcase())
     self.testcases[5].project_name = 'project1'
     self.testcases[5].crash_type = 'crash_type6'
     self.testcases[5].crash_state = 'w5'
+    self.testcases[5].security_flag = True
 
     for t in self.testcases:
       t.put()