unimplement interface: find ref correctly (IDEA-84554)

java/java-impl/src/com/intellij/codeInspection/actions/UnimplementInterfaceAction.java

@@ -91,7 +91,7 @@ public class UnimplementInterfaceAction implements IntentionAction {
   public void invoke(@NotNull final Project project, final Editor editor, final PsiFile file) throws IncorrectOperationException {
     if (!CodeInsightUtilBase.preparePsiElementForWrite(file)) return;
 
-    final PsiReference psiReference = file.findReferenceAt(editor.getCaretModel().getOffset());
+    final PsiReference psiReference = TargetElementUtilBase.findReference(editor);
     if (psiReference == null) return;
 
     final PsiReferenceList referenceList = PsiTreeUtil.getParentOfType(psiReference.getElement(), PsiReferenceList.class);

java/java-tests/testData/codeInsight/daemonCodeAnalyzer/quickFix/unimplement/afterLastPosition.java

@@ -0,0 +1,11 @@
+// "Unimplement Interface" "true"
+class A {
+  public String toString() {
+    return super.toString();
+  }
+
+    public void foo(String ty){}
+}
+
+interface II {
+}

java/java-tests/testData/codeInsight/daemonCodeAnalyzer/quickFix/unimplement/beforeLastPosition.java

@@ -0,0 +1,11 @@
+// "Unimplement Interface" "true"
+class A implements II<caret> {
+  public String toString() {
+    return super.toString();
+  }
+
+    public void foo(String ty){}
+}
+
+interface II {
+}