Merge branch 'UncheckedLeaprYearAfterModification_Refactor_Upstream' of https://github.com/microsoft/codeql into UncheckedLeaprYearAfterModification_Refactor_Upstream

Author: bdrodes

cpp/ql/lib/change-notes/2026-02-06-UncheckedLeapYearAfterModification_Refactor.md

@@ -1,4 +1,4 @@
 ---
 category: minorAnalysis
 ---
-* Refactor of UncheckedLeapYearAfterYearModification.ql to address large numbers of false positives. Reduced alerts from 40k to 2k.
+* Refactored the "Year field changed using an arithmetic operation without checking for leap year" query (`cpp/leap-year/unchecked-after-arithmetic-year-modification`) to address large numbers of false positive results.

cpp/ql/src/Likely Bugs/Leap Year/UncheckedLeapYearAfterYearModification.ql

@@ -783,7 +783,7 @@ class LeapYearGuardCondition extends GuardCondition {
  *        ... values eventually used in the same time struct
  * If this is even more challenging if the struct the values end up in are not
  * local (set inter-procedurally).
- * This flow flows constants 1-31 to a month or day assignment.
+ * This configuration looks for constants 1-31 flowing to a month or day assignment.
  * It is assumed a user of this flow will check if the month/day source and month/day sink
  * are in the same basic blocks as a year modification source and a year modification sink.
  * It is also assumed a user will check if the constant source is a value that is ignorable