FE: add test reproducing KT-54049

analysis/low-level-api-fir/tests/org/jetbrains/kotlin/analysis/low/level/api/fir/diagnostic/compiler/based/DiagnosisCompilerTestFE10TestdataTestGenerated.java

@@ -19588,6 +19588,12 @@ public class DiagnosisCompilerTestFE10TestdataTestGenerated extends AbstractDiag
                 runTest("compiler/testData/diagnostics/tests/java8Overrides/defaultVsAbstract.kt");
             }
 
+            @Test
+            @TestMetadata("falseManyImplementations.kt")
+            public void testFalseManyImplementations() throws Exception {
+                runTest("compiler/testData/diagnostics/tests/java8Overrides/falseManyImplementations.kt");
+            }
+
             @Test
             @TestMetadata("hidingMethodOfAny.kt")
             public void testHidingMethodOfAny() throws Exception {

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

@@ -19588,6 +19588,12 @@ public class FirOldFrontendDiagnosticsTestGenerated extends AbstractFirDiagnosti
                 runTest("compiler/testData/diagnostics/tests/java8Overrides/defaultVsAbstract.kt");
             }
 
+            @Test
+            @TestMetadata("falseManyImplementations.kt")
+            public void testFalseManyImplementations() throws Exception {
+                runTest("compiler/testData/diagnostics/tests/java8Overrides/falseManyImplementations.kt");
+            }
+
             @Test
             @TestMetadata("hidingMethodOfAny.kt")
             public void testHidingMethodOfAny() throws Exception {

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

@@ -19588,6 +19588,12 @@ public class FirOldFrontendDiagnosticsWithLightTreeTestGenerated extends Abstrac
                 runTest("compiler/testData/diagnostics/tests/java8Overrides/defaultVsAbstract.kt");
             }
 
+            @Test
+            @TestMetadata("falseManyImplementations.kt")
+            public void testFalseManyImplementations() throws Exception {
+                runTest("compiler/testData/diagnostics/tests/java8Overrides/falseManyImplementations.kt");
+            }
+
             @Test
             @TestMetadata("hidingMethodOfAny.kt")
             public void testHidingMethodOfAny() throws Exception {

compiler/testData/diagnostics/tests/java8Overrides/falseManyImplementations.fir.kt

@@ -0,0 +1,13 @@
+abstract class ClassEmpty {
+    abstract fun foo()
+}
+
+interface BaseEmpty {
+    fun foo()
+}
+
+interface BaseDefault {
+    fun foo() {}
+}
+
+abstract <!MANY_IMPL_MEMBER_NOT_IMPLEMENTED!>class ClassEmpty_BaseEmpty_BaseDefault<!> : ClassEmpty(), BaseEmpty, BaseDefault

compiler/testData/diagnostics/tests/java8Overrides/falseManyImplementations.kt

@@ -0,0 +1,13 @@
+abstract class ClassEmpty {
+    abstract fun foo()
+}
+
+interface BaseEmpty {
+    fun foo()
+}
+
+interface BaseDefault {
+    fun foo() {}
+}
+
+abstract class ClassEmpty_BaseEmpty_BaseDefault : ClassEmpty(), BaseEmpty, BaseDefault

compiler/testData/diagnostics/tests/java8Overrides/falseManyImplementations.txt

@@ -0,0 +1,31 @@
+package
+
+public interface BaseDefault {
+    public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
+    public open fun foo(): kotlin.Unit
+    public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
+    public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
+}
+
+public interface BaseEmpty {
+    public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
+    public abstract fun foo(): kotlin.Unit
+    public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
+    public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
+}
+
+public abstract class ClassEmpty {
+    public constructor ClassEmpty()
+    public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
+    public abstract fun foo(): kotlin.Unit
+    public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
+    public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
+}
+
+public abstract class ClassEmpty_BaseEmpty_BaseDefault : ClassEmpty, BaseEmpty, BaseDefault {
+    public constructor ClassEmpty_BaseEmpty_BaseDefault()
+    public open override /*3*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
+    public open override /*3*/ /*fake_override*/ fun foo(): kotlin.Unit
+    public open override /*3*/ /*fake_override*/ fun hashCode(): kotlin.Int
+    public open override /*3*/ /*fake_override*/ fun toString(): kotlin.String
+}

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

@@ -19594,6 +19594,12 @@ public class DiagnosticTestGenerated extends AbstractDiagnosticTest {
                 runTest("compiler/testData/diagnostics/tests/java8Overrides/defaultVsAbstract.kt");
             }
 
+            @Test
+            @TestMetadata("falseManyImplementations.kt")
+            public void testFalseManyImplementations() throws Exception {
+                runTest("compiler/testData/diagnostics/tests/java8Overrides/falseManyImplementations.kt");
+            }
+
             @Test
             @TestMetadata("hidingMethodOfAny.kt")
             public void testHidingMethodOfAny() throws Exception {