Merge pull request github#10720 from tamasvajk/kotlin-equals-fix

Kotlin: Consider `::class` type check in `java/unchecked-cast-in-equals`

Author: tamasvajk

java/ql/src/Likely Bugs/Comparison/MissingInstanceofInEquals.ql

@@ -30,6 +30,8 @@ predicate hasTypeTest(Variable v) {
   or
   any(SafeCastExpr sce).getExpr() = v.getAnAccess()
   or
+  any(ClassExpr c).getExpr() = v.getAnAccess()
+  or
   exists(MethodAccess ma |
     ma.getMethod().getName() = "getClass" and
     ma.getQualifier() = v.getAnAccess()

java/ql/test/kotlin/query-tests/MissingInstanceofInEquals/Test.kt

@@ -5,3 +5,9 @@ data class E(val x: Int) {
         return (other as? E)?.x == this.x
     }
 }
+
+data class F(val x: Int) {
+    override fun equals(other: Any?): Boolean {
+        return other != null && other::class == this::class
+    }
+}