From 5948d464114c8ef917c939be85a3f1c0877ebb2a Mon Sep 17 00:00:00 2001
From: Konstantin Ulitin <konstantin.ulitin@jetbrains.com>
Date: Wed, 9 Mar 2016 18:01:05 +0300
Subject: [PATCH] WEB-20680 ES6 unicode code points escape sequences are not
 supported in strings

---
 .../intellij/lexer/StringLiteralLexer.java    | 41 +++++++++++--------
 1 file changed, 25 insertions(+), 16 deletions(-)

diff --git a/platform/core-api/src/com/intellij/lexer/StringLiteralLexer.java b/platform/core-api/src/com/intellij/lexer/StringLiteralLexer.java
index 3b943b9e6018..3703409fcf23 100644
--- a/platform/core-api/src/com/intellij/lexer/StringLiteralLexer.java
+++ b/platform/core-api/src/com/intellij/lexer/StringLiteralLexer.java
@@ -32,13 +32,13 @@ public class StringLiteralLexer extends LexerBase {
 
   public static final char NO_QUOTE_CHAR = (char)-1;
 
-  private CharSequence myBuffer;
-  private int myStart;
-  private int myEnd;
+  protected CharSequence myBuffer;
+  protected int myStart;
+  protected int myEnd;
   private int myState;
   private int myLastState;
-  private int myBufferEnd;
-  private final char myQuoteChar;
+  protected int myBufferEnd;
+  protected final char myQuoteChar;
   private final IElementType myOriginalLiteralToken;
   private final boolean myCanEscapeEolOrFramingSpaces;
   private final String myAdditionalValidEscapes;
@@ -114,10 +114,7 @@ public class StringLiteralLexer extends LexerBase {
       return StringEscapesTokenTypes.VALID_STRING_ESCAPE_TOKEN;
     }
     if (nextChar == 'u') {
-      for(int i = myStart + 2; i < myStart + 6; i++) {
-        if (i >= myEnd || !StringUtil.isHexDigit(myBuffer.charAt(i))) return StringEscapesTokenTypes.INVALID_UNICODE_ESCAPE_TOKEN;
-      }
-      return StringEscapesTokenTypes.VALID_STRING_ESCAPE_TOKEN;
+      return getUnicodeEscapeSequenceType();
     }
 
     if (nextChar == 'x' && myAllowHex) {
@@ -155,6 +152,14 @@ public class StringLiteralLexer extends LexerBase {
     return StringEscapesTokenTypes.INVALID_CHARACTER_ESCAPE_TOKEN;
   }
 
+  @NotNull
+  protected IElementType getUnicodeEscapeSequenceType() {
+    for (int i = myStart + 2; i < myStart + 6; i++) {
+      if (i >= myEnd || !StringUtil.isHexDigit(myBuffer.charAt(i))) return StringEscapesTokenTypes.INVALID_UNICODE_ESCAPE_TOKEN;
+    }
+    return StringEscapesTokenTypes.VALID_STRING_ESCAPE_TOKEN;
+  }
+
   // all subsequent chars are escaped spaces
   private boolean isTrailingSpace(final int start) {
     for (int i=start;i<myBufferEnd;i+=2) {
@@ -213,13 +218,7 @@ public class StringLiteralLexer extends LexerBase {
       }
 
       if (myBuffer.charAt(i) == 'u') {
-        i++;
-        for (; i < start + 6; i++) {
-          if (i == myBufferEnd || myBuffer.charAt(i) == '\n' || myBuffer.charAt(i) == myQuoteChar) {
-            return i;
-          }
-        }
-        return i;
+        return locateUnicodeEscapeSequence(start, i);
       }
       else {
         return i + 1;
@@ -241,6 +240,16 @@ public class StringLiteralLexer extends LexerBase {
     return i;
   }
 
+  protected int locateUnicodeEscapeSequence(int start, int i) {
+    i++;
+    for (; i < start + 6; i++) {
+      if (i == myBufferEnd || myBuffer.charAt(i) == '\n' || myBuffer.charAt(i) == myQuoteChar) {
+        return i;
+      }
+    }
+    return i;
+  }
+
   @Override
   public void advance() {
     myLastState = myState;