Override/Implement Members: Implement Members: Fix base member detection when abstract and non-abstract members with matching signatures are inherited from an interface

#KT-11115 Fixed
(cherry picked from commit a3a2e57)

ChangeLog.md

@@ -113,6 +113,12 @@ These artifacts include extensions for the types available in the latter JDKs, s
 - [`KT-13037`](https://youtrack.jetbrains.com/issue/KT-13037) Fix possible deadlock in debugger in 2016.1 and exception in 2016.2
 - [`KT-12651`](https://youtrack.jetbrains.com/issue/KT-12651) Fix exception in evaluate expression when bad identifier is used for marking object
 
+#### Intention actions, inspections and quickfixes
+
+###### Issues fixed
+
+- [`KT-11115`](https://youtrack.jetbrains.com/issue/KT-11115) Implement Members: Fix base member detection when abstract and non-abstract members with matching signatures are inherited from an interface
+
 #### Refactorings
 
 ###### Issues fixed

compiler/frontend/src/org/jetbrains/kotlin/resolve/OverrideResolver.java

@@ -334,7 +334,9 @@ public class OverrideResolver {
 
         @Override
         public void conflictingInterfaceMemberNotImplemented(CallableMemberDescriptor descriptor) {
-            // don't care
+            if (descriptor.getModality() == Modality.ABSTRACT) {
+                shouldImplement.add(descriptor);
+            }
         }
 
         @Override

idea/testData/codeInsight/overrideImplement/abstractAndNonAbstractInheritedFromInterface.kt

@@ -0,0 +1,11 @@
+interface T {
+    fun getFoo(): String = ""
+}
+
+interface U {
+    fun getFoo(): String
+}
+
+class C1 : T, U {
+    <caret>
+}

idea/testData/codeInsight/overrideImplement/abstractAndNonAbstractInheritedFromInterface.kt.after

@@ -0,0 +1,13 @@
+interface T {
+    fun getFoo(): String = ""
+}
+
+interface U {
+    fun getFoo(): String
+}
+
+class C1 : T, U {
+    override fun getFoo(): String {
+        <selection><caret>TODO("not implemented") //To change body of created functions use File | Settings | File Templates.</selection>
+    }
+}

idea/tests/org/jetbrains/kotlin/idea/codeInsight/OverrideImplementTest.kt

@@ -247,4 +247,8 @@ class OverrideImplementTest : AbstractOverrideImplementTest() {
     fun testPlatformTypes() {
         doOverrideDirectoryTest("foo")
     }
+
+    fun testAbstractAndNonAbstractInheritedFromInterface() {
+        doImplementFileTest("getFoo")
+    }
 }