C++: Add barrier to prevent duplication.

Author: MathiasVP

cpp/ql/src/Likely Bugs/Leap Year/LeapYear.qll

@@ -345,6 +345,8 @@ private module PossibleYearArithmeticOperationCheckConfig implements DataFlow::C
     )
   }
 
+  predicate isBarrierIn(DataFlow::Node node) { isSource(node) }
+
   predicate isAdditionalFlowStep(DataFlow::Node node1, DataFlow::Node node2) {
     // flow from anything on the RHS of an assignment to a time/date structure to that
     // assignment.

cpp/ql/test/query-tests/Likely Bugs/Leap Year/Adding365DaysPerYear/Adding365daysPerYear.expected

@@ -1,5 +1,5 @@
-| test.cpp:173:29:173:51 | ... & ... | An arithmetic operation $@ that uses a constant value of 365 ends up modifying this date/time, without considering leap year scenarios. | test.cpp:170:16:170:47 | ... * ... | ... * ... |
-| test.cpp:174:30:174:45 | ... >> ... | An arithmetic operation $@ that uses a constant value of 365 ends up modifying this date/time, without considering leap year scenarios. | test.cpp:170:16:170:47 | ... * ... | ... * ... |
+| test.cpp:173:29:173:51 | ... & ... | An arithmetic operation $@ that uses a constant value of 365 ends up modifying this date/time, without considering leap year scenarios. | test.cpp:170:2:170:47 | ... += ... | ... += ... |
+| test.cpp:174:30:174:45 | ... >> ... | An arithmetic operation $@ that uses a constant value of 365 ends up modifying this date/time, without considering leap year scenarios. | test.cpp:170:2:170:47 | ... += ... | ... += ... |
 | test.cpp:193:15:193:24 | ... / ... | An arithmetic operation $@ that uses a constant value of 365 ends up modifying this date/time, without considering leap year scenarios. | test.cpp:193:15:193:24 | ... / ... | ... / ... |
-| test.cpp:217:29:217:51 | ... & ... | An arithmetic operation $@ that uses a constant value of 365 ends up modifying this date/time, without considering leap year scenarios. | test.cpp:214:16:214:47 | ... * ... | ... * ... |
-| test.cpp:218:30:218:45 | ... >> ... | An arithmetic operation $@ that uses a constant value of 365 ends up modifying this date/time, without considering leap year scenarios. | test.cpp:214:16:214:47 | ... * ... | ... * ... |
+| test.cpp:217:29:217:51 | ... & ... | An arithmetic operation $@ that uses a constant value of 365 ends up modifying this date/time, without considering leap year scenarios. | test.cpp:214:2:214:47 | ... += ... | ... += ... |
+| test.cpp:218:30:218:45 | ... >> ... | An arithmetic operation $@ that uses a constant value of 365 ends up modifying this date/time, without considering leap year scenarios. | test.cpp:214:2:214:47 | ... += ... | ... += ... |