CPP: Add a test case where a date is created.

Author: geoffw0

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

@@ -9,3 +9,4 @@
 | test.cpp:636:11:636:17 | tm_year | Field $@ on variable $@ has been modified, but no appropriate check for LeapYear was found. | test.cpp:56:6:56:12 | tm_year | tm_year | test.cpp:628:12:628:19 | timeinfo | timeinfo |
 | test.cpp:640:5:640:9 | wYear | Field $@ on variable $@ has been modified, but no appropriate check for LeapYear was found. | test.cpp:12:7:12:11 | wYear | wYear | test.cpp:629:13:629:14 | st | st |
 | test.cpp:642:5:642:9 | wYear | Field $@ on variable $@ has been modified, but no appropriate check for LeapYear was found. | test.cpp:12:7:12:11 | wYear | wYear | test.cpp:629:13:629:14 | st | st |
+| test.cpp:677:5:677:11 | tm_year | Field $@ on variable $@ has been modified, but no appropriate check for LeapYear was found. | test.cpp:56:6:56:12 | tm_year | tm_year | test.cpp:664:12:664:12 | t | t |

cpp/ql/test/query-tests/Likely Bugs/Leap Year/UncheckedLeapYearAfterYearModification/test.cpp

@@ -656,3 +656,27 @@ IncrementMonth(LPSYSTEMTIME pst)
 		pst->wYear++;
 	}
 }
+
+/////////////////////////////////////////////////////////
+
+void mkDateTest(int year)
+{
+	struct tm t;
+
+	t.tm_sec = 0;
+	t.tm_min = 0;
+	t.tm_hour = 0;
+	t.tm_mday = 1;  // day of the month - [1, 31]
+	t.tm_mon = 0;   // months since January - [0, 11]
+	if (year >= 1900)
+	{
+		// 4-digit year
+		t.tm_year = year - 1900; // GOOD
+	} else if ((year >= 0) && (year < 100)) {
+		// 2-digit year assumed in the range 2000 - 2099
+		t.tm_year = year + 100; // GOOD [FALSE POSITIVE]
+	} else {
+		// fail
+	}
+	// ...
+}