Check for the presence of dispatch receiver too in isEqualsDescriptor()

Otherwise, top-level function with the name 'equals' and suitable
signature will be (erroneously) treated as true 'equals' invocation,
leading to further exception (see EA-126602)

compiler/frontend/src/org/jetbrains/kotlin/contracts/parsing/PsiContractsUtils.kt

@@ -87,7 +87,7 @@ fun DeclarationDescriptor.isCallsInPlaceEffectDescriptor(): Boolean = equalsDslD
 fun DeclarationDescriptor.isInvocationKindEnum(): Boolean = equalsDslDescriptor(INVOCATION_KIND_ENUM)
 
 fun DeclarationDescriptor.isEqualsDescriptor(): Boolean =
-    this is FunctionDescriptor && this.name == Name.identifier("equals") && // fast checks
+    this is FunctionDescriptor && this.name == Name.identifier("equals") && dispatchReceiverParameter != null && // fast checks
             this.returnType?.isBoolean() == true && this.valueParameters.singleOrNull()?.type?.isNullableAny() == true // signature matches
 
 internal fun ResolvedCall<*>.firstArgumentAsExpressionOrNull(): KtExpression? =

compiler/testData/diagnostics/tests/override/fakeEquals.kt

@@ -0,0 +1,9 @@
+// !DIAGNOSTICS: -UNUSED_PARAMETER -UNUSED_REFERENCE
+
+class Foo
+
+fun test(a: Foo, b: Foo) {
+    // Note that signature matches the 'equals'
+    fun equals(x: Any?): Boolean = false
+    equals(b)
+}

compiler/testData/diagnostics/tests/override/fakeEquals.txt

@@ -0,0 +1,10 @@
+package
+
+public fun test(/*0*/ a: Foo, /*1*/ b: Foo): kotlin.Unit
+
+public final class Foo {
+    public constructor Foo()
+    public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
+    public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
+    public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
+}

compiler/tests/org/jetbrains/kotlin/checkers/DiagnosticsTestGenerated.java

@@ -14501,6 +14501,11 @@ public class DiagnosticsTestGenerated extends AbstractDiagnosticsTest {
                 runTest("compiler/testData/diagnostics/tests/override/ExtendFunctionClass.kt");
             }
 
+            @TestMetadata("fakeEquals.kt")
+            public void testFakeEquals() throws Exception {
+                runTest("compiler/testData/diagnostics/tests/override/fakeEquals.kt");
+            }
+
             @TestMetadata("FakeOverrideAbstractAndNonAbstractFun.kt")
             public void testFakeOverrideAbstractAndNonAbstractFun() throws Exception {
                 runTest("compiler/testData/diagnostics/tests/override/FakeOverrideAbstractAndNonAbstractFun.kt");

compiler/tests/org/jetbrains/kotlin/checkers/javac/DiagnosticsUsingJavacTestGenerated.java

@@ -14501,6 +14501,11 @@ public class DiagnosticsUsingJavacTestGenerated extends AbstractDiagnosticsUsing
                 runTest("compiler/testData/diagnostics/tests/override/ExtendFunctionClass.kt");
             }
 
+            @TestMetadata("fakeEquals.kt")
+            public void testFakeEquals() throws Exception {
+                runTest("compiler/testData/diagnostics/tests/override/fakeEquals.kt");
+            }
+
             @TestMetadata("FakeOverrideAbstractAndNonAbstractFun.kt")
             public void testFakeOverrideAbstractAndNonAbstractFun() throws Exception {
                 runTest("compiler/testData/diagnostics/tests/override/FakeOverrideAbstractAndNonAbstractFun.kt");