Fixed KT-6110 J2K converter: do not replace accessors implementing interface with property

#KT-6110

j2k/src/org/jetbrains/jet/j2k/ClassBodyConverter.kt

@@ -145,6 +145,7 @@ class ClassBodyConverter(private val psiClass: PsiClass,
         val fieldsWithConflict = HashSet<PsiField>()
         for (method in psiClass.getMethods()) {
             val info = getAccessorInfo(method) ?: continue
+            if (method.getHierarchicalMethodSignature().getSuperSignatures().isNotEmpty()) continue // overrides or implements something
             val map = if (info.kind == AccessorKind.GETTER) fieldToGetterInfo else fieldToSetterInfo
 
             val prevInfo = map[info.field]

j2k/tests/test/org/jetbrains/jet/j2k/test/JavaToKotlinConverterSingleFileTestGenerated.java

@@ -1301,6 +1301,12 @@ public class JavaToKotlinConverterSingleFileTestGenerated extends AbstractJavaTo
             doTest(fileName);
         }
 
+        @TestMetadata("AccessorsImplementInterface.java")
+        public void testAccessorsImplementInterface() throws Exception {
+            String fileName = JetTestUtils.navigationMetadata("j2k/tests/testData/fileOrElement/dropAccessors/AccessorsImplementInterface.java");
+            doTest(fileName);
+        }
+
         public void testAllFilesPresentInDropAccessors() throws Exception {
             JetTestUtils.assertAllTestsPresentByMetadata(this.getClass(), new File("j2k/tests/testData/fileOrElement/dropAccessors"), Pattern.compile("^(.+)\\.java$"), true);
         }

j2k/tests/testData/fileOrElement/dropAccessors/AccessorsImplementInterface.java

@@ -0,0 +1,20 @@
+interface I {
+    int getX();
+    void setX(int x);
+}
+
+class A implements I {
+    private int x;
+
+    public A(int x) {
+        this.x = x;
+    }
+
+    public int getX() {
+        return x;
+    }
+
+    public void setX(int x){
+        this.x = x;
+    }
+}

j2k/tests/testData/fileOrElement/dropAccessors/AccessorsImplementInterface.kt

@@ -0,0 +1,15 @@
+trait I {
+    public fun getX(): Int
+    public fun setX(x: Int)
+}
+
+class A(private var x: Int) : I {
+
+    override fun getX(): Int {
+        return x
+    }
+
+    override fun setX(x: Int) {
+        this.x = x
+    }
+}