JVM IR: don't rename fake overrides for fields

In case derived class has a field with the same name as the base class,
RenameFieldsLowering previously tried to rename one of the fields by
adding the "...$1" suffix, which led to NoSuchFieldError.

compiler/fir/fir2ir/tests/org/jetbrains/kotlin/codegen/ir/FirBlackBoxCodegenTestGenerated.java

@@ -14619,6 +14619,11 @@ public class FirBlackBoxCodegenTestGenerated extends AbstractFirBlackBoxCodegenT
             runTest("compiler/testData/codegen/box/jvmField/checkNoAccessors.kt");
         }
 
+        @TestMetadata("clashWithJavaSuperClassField.kt")
+        public void testClashWithJavaSuperClassField() throws Exception {
+            runTest("compiler/testData/codegen/box/jvmField/clashWithJavaSuperClassField.kt");
+        }
+
         @TestMetadata("classFieldReference.kt")
         public void testClassFieldReference() throws Exception {
             runTest("compiler/testData/codegen/box/jvmField/classFieldReference.kt");

compiler/ir/backend.jvm/src/org/jetbrains/kotlin/backend/jvm/lower/RenameFieldsLowering.kt

@@ -96,7 +96,9 @@ private class FieldNameCollector : IrElementVisitorVoid {
     }
 
     override fun visitField(declaration: IrField) {
-        nameToField.getOrPut(declaration.parent to declaration.name) { mutableListOf() }.add(declaration)
+        if (!declaration.isFakeOverride) {
+            nameToField.getOrPut(declaration.parent to declaration.name) { mutableListOf() }.add(declaration)
+        }
     }
 }
 

compiler/testData/codegen/box/jvmField/clashWithJavaSuperClassField.kt

@@ -0,0 +1,19 @@
+// TARGET_BACKEND: JVM
+// IGNORE_BACKEND_FIR: JVM_IR
+// WITH_RUNTIME
+// FILE: test.kt
+
+abstract class A {
+    @JvmField
+    protected var flag: String = "Fail"
+}
+
+fun box(): String = object : J() {
+    val result = flag
+}.result
+
+// FILE: J.java
+
+public class J extends A {
+    protected String flag = "OK";
+}

compiler/tests/org/jetbrains/kotlin/codegen/BlackBoxCodegenTestGenerated.java

@@ -15764,6 +15764,11 @@ public class BlackBoxCodegenTestGenerated extends AbstractBlackBoxCodegenTest {
             runTest("compiler/testData/codegen/box/jvmField/checkNoAccessors.kt");
         }
 
+        @TestMetadata("clashWithJavaSuperClassField.kt")
+        public void testClashWithJavaSuperClassField() throws Exception {
+            runTest("compiler/testData/codegen/box/jvmField/clashWithJavaSuperClassField.kt");
+        }
+
         @TestMetadata("classFieldReference.kt")
         public void testClassFieldReference() throws Exception {
             runTest("compiler/testData/codegen/box/jvmField/classFieldReference.kt");

compiler/tests/org/jetbrains/kotlin/codegen/LightAnalysisModeTestGenerated.java

@@ -15764,6 +15764,11 @@ public class LightAnalysisModeTestGenerated extends AbstractLightAnalysisModeTes
             runTest("compiler/testData/codegen/box/jvmField/checkNoAccessors.kt");
         }
 
+        @TestMetadata("clashWithJavaSuperClassField.kt")
+        public void testClashWithJavaSuperClassField() throws Exception {
+            runTest("compiler/testData/codegen/box/jvmField/clashWithJavaSuperClassField.kt");
+        }
+
         @TestMetadata("classFieldReference.kt")
         public void testClassFieldReference() throws Exception {
             runTest("compiler/testData/codegen/box/jvmField/classFieldReference.kt");

compiler/tests/org/jetbrains/kotlin/codegen/ir/IrBlackBoxCodegenTestGenerated.java

@@ -14619,6 +14619,11 @@ public class IrBlackBoxCodegenTestGenerated extends AbstractIrBlackBoxCodegenTes
             runTest("compiler/testData/codegen/box/jvmField/checkNoAccessors.kt");
         }
 
+        @TestMetadata("clashWithJavaSuperClassField.kt")
+        public void testClashWithJavaSuperClassField() throws Exception {
+            runTest("compiler/testData/codegen/box/jvmField/clashWithJavaSuperClassField.kt");
+        }
+
         @TestMetadata("classFieldReference.kt")
         public void testClassFieldReference() throws Exception {
             runTest("compiler/testData/codegen/box/jvmField/classFieldReference.kt");