From 971ba07c243b554fad3410024a55b52a6dfeed37 Mon Sep 17 00:00:00 2001
From: Bas Leijdekkers <basleijdekkers@gmail.com>
Date: Mon, 25 Mar 2019 11:34:58 +0100
Subject: [PATCH] RegExp: redundantly escaped 'u' not correctly unescaped
 (IDEA-208559)

---
 .../lang/regexp/psi/impl/RegExpCharImpl.java  |  2 +-
 .../RedundantEscapeInspectionTest.java        | 23 +++++++------------
 2 files changed, 9 insertions(+), 16 deletions(-)

diff --git a/RegExpSupport/src/org/intellij/lang/regexp/psi/impl/RegExpCharImpl.java b/RegExpSupport/src/org/intellij/lang/regexp/psi/impl/RegExpCharImpl.java
index 76c80ac8b6a0..0dd8a0a800d1 100644
--- a/RegExpSupport/src/org/intellij/lang/regexp/psi/impl/RegExpCharImpl.java
+++ b/RegExpSupport/src/org/intellij/lang/regexp/psi/impl/RegExpCharImpl.java
@@ -106,7 +106,7 @@ public class RegExpCharImpl extends RegExpElementImpl implements RegExpChar {
                 }
                 return length == 4 ? parseNumber(s, 2, 16) : -1;
             case 'u':
-                if (length <= 2) return -1;
+                if (length <= 2) return 'u';
                 if (s.charAt(2) == '{') {
                     final char c = s.charAt(length - 1);
                     return (c != '}') ? -1 : parseNumber(s, 3, 16);
diff --git a/RegExpSupport/test/org/intellij/lang/regexp/inspection/RedundantEscapeInspectionTest.java b/RegExpSupport/test/org/intellij/lang/regexp/inspection/RedundantEscapeInspectionTest.java
index 8911630765d9..841051714568 100644
--- a/RegExpSupport/test/org/intellij/lang/regexp/inspection/RedundantEscapeInspectionTest.java
+++ b/RegExpSupport/test/org/intellij/lang/regexp/inspection/RedundantEscapeInspectionTest.java
@@ -1,21 +1,9 @@
-/*
- * Copyright 2000-2017 JetBrains s.r.o.
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- * http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
+// Copyright 2000-2019 JetBrains s.r.o. Use of this source code is governed by the Apache 2.0 license that can be found in the LICENSE file.
 package org.intellij.lang.regexp.inspection;
 
 import com.intellij.codeInspection.LocalInspectionTool;
+import org.intellij.lang.regexp.RegExpFileType;
+import org.intellij.lang.regexp.ecmascript.EcmaScriptRegexpLanguage;
 import org.jetbrains.annotations.NotNull;
 
 /**
@@ -36,6 +24,11 @@ public class RedundantEscapeInspectionTest extends RegExpInspectionTestCase {
     highlightTest("a<warning descr=\"Redundant character escape '\\ ' in RegExp\">\\ </warning>b<warning descr=\"Redundant character escape '\\ ' in RegExp\">\\ </warning>c");
   }
 
+  public void testEscapedU() {
+    quickfixTest("<warning descr=\"Redundant character escape '\\u' in RegExp\">\\u</warning>", "u", "Remove redundant escape",
+                 new RegExpFileType(EcmaScriptRegexpLanguage.INSTANCE));
+  }
+
   @NotNull
   @Override
   protected LocalInspectionTool getInspection() {