Add a test for KT-54318

compiler/fir/fir2ir/tests-gen/org/jetbrains/kotlin/test/runners/codegen/FirBlackBoxCodegenTestGenerated.java

@@ -4793,6 +4793,12 @@ public class FirBlackBoxCodegenTestGenerated extends AbstractFirBlackBoxCodegenT
             runTest("compiler/testData/codegen/box/casts/kt53677.kt");
         }
 
+        @Test
+        @TestMetadata("kt54318.kt")
+        public void testKt54318() throws Exception {
+            runTest("compiler/testData/codegen/box/casts/kt54318.kt");
+        }
+
         @Test
         @TestMetadata("lambdaToUnitCast.kt")
         public void testLambdaToUnitCast() throws Exception {

compiler/testData/codegen/box/casts/kt54318.kt

@@ -0,0 +1,19 @@
+// TARGET_BACKEND: JVM_IR
+
+fun f(b: Int): Long? {
+    return try {
+        null
+    } catch (e: Throwable) {
+        if (b == 0)
+            throw e
+        else {
+            null
+        }
+    }
+}
+
+fun box(): String {
+    f(0)
+    f(1)
+    return "OK"
+}

compiler/tests-common-new/tests-gen/org/jetbrains/kotlin/test/runners/codegen/IrBlackBoxCodegenTestGenerated.java

@@ -4793,6 +4793,12 @@ public class IrBlackBoxCodegenTestGenerated extends AbstractIrBlackBoxCodegenTes
             runTest("compiler/testData/codegen/box/casts/kt53677.kt");
         }
 
+        @Test
+        @TestMetadata("kt54318.kt")
+        public void testKt54318() throws Exception {
+            runTest("compiler/testData/codegen/box/casts/kt54318.kt");
+        }
+
         @Test
         @TestMetadata("lambdaToUnitCast.kt")
         public void testLambdaToUnitCast() throws Exception {