JVM_IR: handle diamond inheritance for Java fields

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

@@ -16014,6 +16014,11 @@ public class FirBlackBoxCodegenTestGenerated extends AbstractFirBlackBoxCodegenT
             runTest("compiler/testData/codegen/box/jvmField/constructorProperty.kt");
         }
 
+        @TestMetadata("diamond.kt")
+        public void testDiamond() throws Exception {
+            runTest("compiler/testData/codegen/box/jvmField/diamond.kt");
+        }
+
         @TestMetadata("fileOrder.kt")
         public void testFileOrder() throws Exception {
             runTest("compiler/testData/codegen/box/jvmField/fileOrder.kt");

compiler/ir/ir.psi2ir/src/org/jetbrains/kotlin/psi2ir/KotlinUtils.kt

@@ -79,12 +79,13 @@ val PropertyDescriptor.unwrappedSetMethod: FunctionDescriptor?
 
 // Only works for descriptors of Java fields.
 internal fun PropertyDescriptor.resolveFakeOverride(): PropertyDescriptor {
-    assert(getter == null)
+    assert(getter == null) { "resolveFakeOverride should only be called for Java fields, got $this"}
-    // Fields can only be inherited from objects, so there will be at most one overridden descriptor at each step.
     var current = this
     while (current.kind == CallableMemberDescriptor.Kind.FAKE_OVERRIDE) {
-        current = current.overriddenDescriptors.singleOrNull()
+        current = current.overriddenDescriptors.singleOrNull {
-            ?: error("Descriptor of Java field $current should have exactly one overridden descriptor, have ${current.overriddenDescriptors}")
+            (it.containingDeclaration as ClassDescriptor).kind != ClassKind.INTERFACE
+        } ?: current.overriddenDescriptors.firstOrNull()
+                ?: error("Fake override descriptor of Java field $current should has no overridden descriptors")
     }
     return current
 }

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

@@ -0,0 +1,14 @@
+// TARGET_BACKEND: JVM
+// IGNORE_BACKEND_FIR: JVM_IR
+// FILE: A.java
+public interface A { public String ok = "OK"; }
+// FILE: B.java
+public class B implements A {}
+// FILE: C.java
+public class C extends B implements A {}
+// FILE: test.kt
+class D: C() {
+    fun okay() = ok
+}
+
+fun box() = D().okay()

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

@@ -17239,6 +17239,11 @@ public class BlackBoxCodegenTestGenerated extends AbstractBlackBoxCodegenTest {
             runTest("compiler/testData/codegen/box/jvmField/constructorProperty.kt");
         }
 
+        @TestMetadata("diamond.kt")
+        public void testDiamond() throws Exception {
+            runTest("compiler/testData/codegen/box/jvmField/diamond.kt");
+        }
+
         @TestMetadata("fileOrder.kt")
         public void testFileOrder() throws Exception {
             runTest("compiler/testData/codegen/box/jvmField/fileOrder.kt");

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

@@ -17239,6 +17239,11 @@ public class LightAnalysisModeTestGenerated extends AbstractLightAnalysisModeTes
             runTest("compiler/testData/codegen/box/jvmField/constructorProperty.kt");
         }
 
+        @TestMetadata("diamond.kt")
+        public void testDiamond() throws Exception {
+            runTest("compiler/testData/codegen/box/jvmField/diamond.kt");
+        }
+
         @TestMetadata("fileOrder.kt")
         public void testFileOrder() throws Exception {
             runTest("compiler/testData/codegen/box/jvmField/fileOrder.kt");

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

@@ -16014,6 +16014,11 @@ public class IrBlackBoxCodegenTestGenerated extends AbstractIrBlackBoxCodegenTes
             runTest("compiler/testData/codegen/box/jvmField/constructorProperty.kt");
         }
 
+        @TestMetadata("diamond.kt")
+        public void testDiamond() throws Exception {
+            runTest("compiler/testData/codegen/box/jvmField/diamond.kt");
+        }
+
         @TestMetadata("fileOrder.kt")
         public void testFileOrder() throws Exception {
             runTest("compiler/testData/codegen/box/jvmField/fileOrder.kt");