FIR2IR: add fallback for a synthetic property override situation

compiler/fir/fir2ir/src/org/jetbrains/kotlin/fir/backend/Fir2IrDeclarationStorage.kt

@@ -1191,13 +1191,15 @@ class Fir2IrDeclarationStorage(
         if (fir.isLocal) {
             return localStorage.getDelegatedProperty(fir)?.symbol ?: getIrVariableSymbol(fir)
         }
-        val unmatchedReceiver = dispatchReceiverLookupTag != firPropertySymbol.containingClass()
+        val containingClassLookupTag = firPropertySymbol.containingClass()
+        val unmatchedReceiver = dispatchReceiverLookupTag != containingClassLookupTag
         if (unmatchedReceiver) {
             generateLazyFakeOverrides(fir.name, dispatchReceiverLookupTag)
         }
-        val originalSymbol = getIrCallableSymbol(
+
+        fun ConeClassLikeLookupTag?.getIrCallableSymbol() = getIrCallableSymbol(
             firPropertySymbol,
-            dispatchReceiverLookupTag,
+            dispatchReceiverLookupTag = this,
             getCachedIrDeclaration = ::getCachedIrProperty,
             createIrDeclaration = { parent, origin -> createIrProperty(fir, parent, predefinedOrigin = origin) },
             createIrLazyDeclaration = { signature, lazyParent, declarationOrigin ->
@@ -1219,13 +1221,34 @@ class Fir2IrDeclarationStorage(
                 return symbol
             }
         )
+
+        val originalSymbol = dispatchReceiverLookupTag.getIrCallableSymbol()
+        val originalProperty = originalSymbol.owner as IrProperty
+
+        fun IrProperty.isIllegalFakeOverride(): Boolean {
+            if (!isFakeOverride) return false
+            val overriddenSymbols = overriddenSymbols
+            if (overriddenSymbols.isEmpty() || overriddenSymbols.any { it.owner.isIllegalFakeOverride() }) {
+                return true
+            }
+            return false
+        }
+
+        if (dispatchReceiverLookupTag != null &&
+            firPropertySymbol is FirSyntheticPropertySymbol &&
+            originalProperty.isIllegalFakeOverride()
+        ) {
+            // Fallback for a synthetic property complex case
+            return containingClassLookupTag.getIrCallableSymbol()
+        }
+
         return if (dispatchReceiverLookupTag is ConeClassLookupTagWithFixedSymbol &&
-            dispatchReceiverLookupTag != firPropertySymbol.containingClass()
+            dispatchReceiverLookupTag != containingClassLookupTag
         ) {
             val dispatchReceiverIrClass =
                 classifierStorage.getIrClassSymbol(dispatchReceiverLookupTag.toSymbol(session) as FirClassSymbol).owner
             dispatchReceiverIrClass.declarations.find {
-                it is IrProperty && it.isFakeOverride && it.name == fir.name && it.overrides(originalSymbol.owner as IrProperty)
+                it is IrProperty && it.isFakeOverride && it.name == fir.name && it.overrides(originalProperty)
             }?.symbol as IrPropertySymbol
         } else {
             originalSymbol

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

@@ -16342,6 +16342,12 @@ public class FirBlackBoxCodegenTestGenerated extends AbstractFirBlackBoxCodegenT
             runTest("compiler/testData/codegen/box/fir/ConstValAccess.kt");
         }
 
+        @Test
+        @TestMetadata("CustomHashSetSize.kt")
+        public void testCustomHashSetSize() throws Exception {
+            runTest("compiler/testData/codegen/box/fir/CustomHashSetSize.kt");
+        }
+
         @Test
         @TestMetadata("CustomThrowableMessage.kt")
         public void testCustomThrowableMessage() throws Exception {

compiler/testData/codegen/box/fir/CustomHashSetSize.kt

@@ -0,0 +1,65 @@
+// TARGET_BACKEND: JVM_IR
+// WITH_RUNTIME
+
+// MODULE: m1
+// FILE: m1/THash.java
+
+package m1;
+
+public class THash {
+
+    public int size() { return 1; }
+}
+
+// FILE: m1/TObjectHash.java
+
+package m1;
+
+public class TObjectHash<T> extends THash {}
+
+// FILE: m1/THashSet.java
+
+package m1;
+import java.util.*;
+
+public class THashSet<T> extends TObjectHash<T> implements Set<T> {
+    public Iterator<T> iterator() { return null; }
+
+    public boolean isEmpty() { return false; }
+
+    public boolean contains(Object o) { return false; }
+
+    public Object[] toArray() { return new Object[1]; }
+
+    public <T> T[] toArray(T[] a) { throw new RuntimeException(); }
+
+    public boolean add(T e) { return false; }
+
+    public boolean remove(Object o) { return false; }
+
+    public boolean containsAll(Collection<?> c) { return false; }
+
+    public boolean addAll(Collection<? extends T> c) { return false; }
+
+    public boolean retainAll(Collection<?> c) { return false; }
+
+    public boolean removeAll(Collection<?> c) { return false; }
+
+    public void clear() {}
+}
+
+// MODULE: m2(m1)
+// FILE: box.kt
+
+package m2
+import m1.THashSet
+
+interface HeaderSet : Set<String>
+
+class MutableHeaderSet : HeaderSet, MutableSet<String>, THashSet<String>()
+
+fun box(): String {
+    val size1 = THashSet<String>().size
+    val size2 = MutableHeaderSet().size
+    return if (size1 == 1 && size2 == 1) "OK" else "$size1/$size2"
+}

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

@@ -16342,6 +16342,12 @@ public class IrBlackBoxCodegenTestGenerated extends AbstractIrBlackBoxCodegenTes
             runTest("compiler/testData/codegen/box/fir/ConstValAccess.kt");
         }
 
+        @Test
+        @TestMetadata("CustomHashSetSize.kt")
+        public void testCustomHashSetSize() throws Exception {
+            runTest("compiler/testData/codegen/box/fir/CustomHashSetSize.kt");
+        }
+
         @Test
         @TestMetadata("CustomThrowableMessage.kt")
         public void testCustomThrowableMessage() throws Exception {