[FIR] Consider extension receiver type in conflicting members checker

compiler/fir/analysis-tests/legacy-fir-tests/tests-gen/org/jetbrains/kotlin/fir/LazyBodyIsNotTouchedTilContractsPhaseTestGenerated.java

@@ -2701,6 +2701,11 @@ public class LazyBodyIsNotTouchedTilContractsPhaseTestGenerated extends Abstract
             runTest("compiler/fir/analysis-tests/testData/resolve/overrides/protobufExt.kt");
         }
 
+        @TestMetadata("sameValueParametersDifferentReceiver.kt")
+        public void testSameValueParametersDifferentReceiver() throws Exception {
+            runTest("compiler/fir/analysis-tests/testData/resolve/overrides/sameValueParametersDifferentReceiver.kt");
+        }
+
         @TestMetadata("simple.kt")
         public void testSimple() throws Exception {
             runTest("compiler/fir/analysis-tests/testData/resolve/overrides/simple.kt");

compiler/fir/analysis-tests/testData/resolve/overrides/sameValueParametersDifferentReceiver.fir.txt

@@ -0,0 +1,21 @@
+FILE: sameValueParametersDifferentReceiver.kt
+    public open class A : R|kotlin/Any| {
+        public constructor(): R|A| {
+            super<R|kotlin/Any|>()
+        }
+
+        public final fun R|kotlin/String|.foo(from: R|kotlin/String|, to: R|kotlin/String|): R|kotlin/Int| {
+            ^foo Int(1)
+        }
+
+        public final fun <T> R|T|.foo(from: R|kotlin/String|, to: R|kotlin/String|): R|kotlin/Int| {
+            ^foo Int(1)
+        }
+
+    }
+    public final class B : R|A| {
+        public constructor(): R|B| {
+            super<R|A|>()
+        }
+
+    }

compiler/fir/analysis-tests/testData/resolve/overrides/sameValueParametersDifferentReceiver.kt

@@ -0,0 +1,11 @@
+open class A {
+    fun String.foo(from: String, to: String): Int {
+        return 1
+    }
+
+    fun <T> T.foo(from: String, to: String): Int {
+        return 1
+    }
+}
+
+class B : A()

compiler/fir/analysis-tests/tests-gen/org/jetbrains/kotlin/test/runners/FirDiagnosticTestGenerated.java

@@ -3059,6 +3059,12 @@ public class FirDiagnosticTestGenerated extends AbstractFirDiagnosticTest {
                 runTest("compiler/fir/analysis-tests/testData/resolve/overrides/protobufExt.kt");
             }
 
+            @Test
+            @TestMetadata("sameValueParametersDifferentReceiver.kt")
+            public void testSameValueParametersDifferentReceiver() throws Exception {
+                runTest("compiler/fir/analysis-tests/testData/resolve/overrides/sameValueParametersDifferentReceiver.kt");
+            }
+
             @Test
             @TestMetadata("simple.kt")
             public void testSimple() throws Exception {

compiler/fir/analysis-tests/tests-gen/org/jetbrains/kotlin/test/runners/FirDiagnosticsWithLightTreeTestGenerated.java

@@ -3059,6 +3059,12 @@ public class FirDiagnosticsWithLightTreeTestGenerated extends AbstractFirDiagnos
                 runTest("compiler/fir/analysis-tests/testData/resolve/overrides/protobufExt.kt");
             }
 
+            @Test
+            @TestMetadata("sameValueParametersDifferentReceiver.kt")
+            public void testSameValueParametersDifferentReceiver() throws Exception {
+                runTest("compiler/fir/analysis-tests/testData/resolve/overrides/sameValueParametersDifferentReceiver.kt");
+            }
+
             @Test
             @TestMetadata("simple.kt")
             public void testSimple() throws Exception {

compiler/fir/checkers/src/org/jetbrains/kotlin/fir/analysis/checkers/declaration/FirImplementationMismatchChecker.kt

@@ -31,6 +31,7 @@ import org.jetbrains.kotlin.fir.types.ConeTypeCheckerContext
 import org.jetbrains.kotlin.fir.types.coneType
 import org.jetbrains.kotlin.name.Name
 import org.jetbrains.kotlin.types.AbstractTypeChecker
+import org.jetbrains.kotlin.utils.addIfNotNull
 
 object FirImplementationMismatchChecker : FirClassChecker() {
 
@@ -182,6 +183,7 @@ object FirImplementationMismatchChecker : FirClassChecker() {
         reporter.reportOn(containingClass.source, FirErrors.VAR_OVERRIDDEN_BY_VAL_BY_DELEGATION, symbol, overriddenVar, context)
     }
 
+    @OptIn(ExperimentalStdlibApi::class)
     private fun checkConflictingMembers(
         containingClass: FirClass,
         context: CheckerContext,
@@ -200,7 +202,10 @@ object FirImplementationMismatchChecker : FirClassChecker() {
         }
 
         val sameArgumentGroups = allFunctions.groupBy { function ->
-            function.valueParameterSymbols.map { it.resolvedReturnTypeRef.coneType }
+            buildList<ConeKotlinType> {
+                addIfNotNull(function.resolvedReceiverTypeRef?.type)
+                function.valueParameterSymbols.mapTo(this) { it.resolvedReturnTypeRef.coneType }
+            }
         }.values
 
         val clashes = sameArgumentGroups.mapNotNull { fs ->

idea/idea-frontend-fir/idea-fir-low-level-api/tests/org/jetbrains/kotlin/idea/fir/low/level/api/diagnostic/compiler/based/DiagnosisCompilerFirTestdataTestGenerated.java

@@ -3059,6 +3059,12 @@ public class DiagnosisCompilerFirTestdataTestGenerated extends AbstractDiagnosis
                 runTest("compiler/fir/analysis-tests/testData/resolve/overrides/protobufExt.kt");
             }
 
+            @Test
+            @TestMetadata("sameValueParametersDifferentReceiver.kt")
+            public void testSameValueParametersDifferentReceiver() throws Exception {
+                runTest("compiler/fir/analysis-tests/testData/resolve/overrides/sameValueParametersDifferentReceiver.kt");
+            }
+
             @Test
             @TestMetadata("simple.kt")
             public void testSimple() throws Exception {