Ignore redundant projections for declaration-site variance

compiler/backend/src/org/jetbrains/kotlin/codegen/state/JetTypeMapper.java

@@ -692,17 +692,17 @@ public class JetTypeMapper {
             @NotNull TypeMappingMode mode
     ) {
         Variance projectionKind = projection.getProjectionKind();
-
-        if (mode.getSkipDeclarationSiteWildcards() && projectionKind == Variance.INVARIANT) {
-            return Variance.INVARIANT;
-        }
-
         Variance parameterVariance = parameter.getVariance();
+
         if (parameterVariance == Variance.INVARIANT) {
             return projectionKind;
         }
 
-        if (projectionKind == Variance.INVARIANT) {
+        if (mode.getSkipDeclarationSiteWildcards()) {
+            return Variance.INVARIANT;
+        }
+
+        if (projectionKind == Variance.INVARIANT || projectionKind == parameterVariance) {
             if (mode.getSkipDeclarationSiteWildcardsIfPossible() && !projection.isStarProjection()) {
                 if (parameterVariance == Variance.OUT_VARIANCE && TypeMappingUtil.isMostPreciseCovariantArgument(projection.getType())){
                     return Variance.INVARIANT;
@@ -715,9 +715,6 @@ public class JetTypeMapper {
             }
             return parameterVariance;
         }
-        if (parameterVariance == projectionKind) {
-            return parameterVariance;
-        }
 
         // In<out X> = In<*>
         // Out<in X> = Out<*>

compiler/testData/codegen/boxWithStdlib/fullJdk/genericMethodSignature.kt

@@ -28,8 +28,8 @@ fun box(): String {
             Params(1, javaClass<Any>(), "T", "T"),
             Params(2, javaClass<Z<*>>(), "Z<T>", "Z<T>"),
             Params(3, javaClass<Z<*>>(), "Z<java.lang.String>", "Z<java.lang.String>"),
-            Params(4, javaClass<Any>(), "Zout<? extends java.lang.String>", "X"),
-            Params(5, javaClass<Any>(), "Zin<? super TParam>", "Y")
+            Params(4, javaClass<Any>(), "Zout<java.lang.String>", "X"),
+            Params(5, javaClass<Any>(), "Zin<TParam>", "Y")
     )
 
 

compiler/testData/writeSignature/declarationSiteVariance/RedundantProjections.kt

@@ -0,0 +1,17 @@
+class Out<out E>
+interface Open
+class Final
+
+fun foo(x: Out<out Open>, y: Out<out Final>): Out<out Open> = Out()
+
+// method: RedundantProjectionsKt::foo
+// jvm signature: (LOut;LOut;)LOut;
+// generic signature: (LOut<+LOpen;>;LOut<LFinal;>;)LOut<LOpen;>;
+
+class In<in F>
+
+fun bar(x: In<in Open>, y: In<in Any?>): In<in Open> = In()
+
+// method: RedundantProjectionsKt::bar
+// jvm signature: (LIn;LIn;)LIn;
+// generic signature: (LIn<-LOpen;>;LIn<Ljava/lang/Object;>;)LIn<LOpen;>;

compiler/tests/org/jetbrains/kotlin/jvm/compiler/WriteSignatureTestGenerated.java

@@ -355,6 +355,12 @@ public class WriteSignatureTestGenerated extends AbstractWriteSignatureTest {
             doTest(fileName);
         }
 
+        @TestMetadata("RedundantProjections.kt")
+        public void testRedundantProjections() throws Exception {
+            String fileName = KotlinTestUtils.navigationMetadata("compiler/testData/writeSignature/declarationSiteVariance/RedundantProjections.kt");
+            doTest(fileName);
+        }
+
         @TestMetadata("SuperClassWithVariance.kt")
         public void testSuperClassWithVariance() throws Exception {
             String fileName = KotlinTestUtils.navigationMetadata("compiler/testData/writeSignature/declarationSiteVariance/SuperClassWithVariance.kt");