Report conflicting signatures that are purely inherited from traits

When all signatures are inherited from traits, the origin elements lie outside of the class in question

compiler/backend/src/org/jetbrains/jet/codegen/state/GenerationState.java

@@ -18,6 +18,8 @@ package org.jetbrains.jet.codegen.state;
 
 import com.intellij.openapi.project.Project;
 import com.intellij.psi.PsiElement;
+import kotlin.Function1;
+import kotlin.KotlinPackage;
 import org.jetbrains.annotations.NotNull;
 import org.jetbrains.annotations.Nullable;
 import org.jetbrains.jet.codegen.*;
@@ -37,6 +39,7 @@ import org.jetbrains.jet.lang.resolve.java.diagnostics.ConflictingJvmDeclaration
 import org.jetbrains.jet.lang.resolve.java.diagnostics.ErrorsJvm;
 import org.jetbrains.jet.lang.resolve.java.diagnostics.JvmDeclarationOrigin;
 import org.jetbrains.jet.lang.resolve.name.FqName;
+import org.jetbrains.jet.lang.resolve.java.diagnostics.JvmDeclarationOriginKind;
 
 import java.util.Collection;
 import java.util.Collections;
@@ -287,9 +290,18 @@ public class GenerationState {
         ) {
             Collection<PsiElement> elements = new LinkedHashSet<PsiElement>();
 
+            boolean allDelegatedToTraitImpls = KotlinPackage.all(
+                    data.getSignatureOrigins(),
+                    new Function1<JvmDeclarationOrigin, Boolean>() {
+                        @Override
+                        public Boolean invoke(JvmDeclarationOrigin origin) {
+                            return origin.getOriginKind() == JvmDeclarationOriginKind.DELEGATION_TO_TRAIT_IMPL;
+                        }
+                    }
+            );
             for (JvmDeclarationOrigin origin : data.getSignatureOrigins()) {
                 PsiElement element = origin.getElement();
-                if (element == null) {
+                if (element == null || allDelegatedToTraitImpls) {
                     element = data.getClassOrigin().getElement();
                 }
                 if (element != null) {

compiler/testData/diagnostics/tests/duplicateJvmSignature/erasure/inheritFromTwoTraits.kt

@@ -8,5 +8,5 @@ trait Bar<T> {
     fun foo(l: List<T>) {}
 }
 
-<!CONFLICTING_JVM_DECLARATIONS!>class Baz()<!>: Foo<String>, Bar<Int> {
+class <!CONFLICTING_JVM_DECLARATIONS!>Baz()<!>: Foo<String>, Bar<Int> {
 }

compiler/testData/diagnostics/tests/duplicateJvmSignature/erasure/twoTraitsAndOwnFunction.kt

@@ -0,0 +1,13 @@
+// !DIAGNOSTICS: -UNUSED_PARAMETER
+
+trait Foo<T> {
+    fun foo(l: List<T>) {}
+}
+
+trait Bar<T> {
+    fun foo(l: List<T>) {}
+}
+
+class Baz(): Foo<String>, Bar<Int> {
+    <!CONFLICTING_JVM_DECLARATIONS!>fun foo(l: List<Long>)<!> {}
+}

compiler/testData/diagnostics/tests/duplicateJvmSignature/traitImpl/twoTraits.kt

@@ -7,5 +7,5 @@ trait T2 {
         get() = 1
 }
 
-<!CONFLICTING_JVM_DECLARATIONS!>class C : T1, T2<!> {
+class <!CONFLICTING_JVM_DECLARATIONS!>C<!> : T1, T2 {
 }

compiler/tests/org/jetbrains/jet/checkers/JetDiagnosticsTestGenerated.java

@@ -2626,6 +2626,11 @@ public class JetDiagnosticsTestGenerated extends AbstractJetDiagnosticsTest {
                     doTest("compiler/testData/diagnostics/tests/duplicateJvmSignature/erasure/nullableType.kt");
                 }
                 
+                @TestMetadata("twoTraitsAndOwnFunction.kt")
+                public void testTwoTraitsAndOwnFunction() throws Exception {
+                    doTest("compiler/testData/diagnostics/tests/duplicateJvmSignature/erasure/twoTraitsAndOwnFunction.kt");
+                }
+                
                 @TestMetadata("typeMappedToJava.kt")
                 public void testTypeMappedToJava() throws Exception {
                     doTest("compiler/testData/diagnostics/tests/duplicateJvmSignature/erasure/typeMappedToJava.kt");