src/jdk/nashorn/internal/parser/Lexer.java

*** 646,656 ****
       * @param ch   Character to convert.
       * @param base Numeric base.
       *
       * @return The converted digit or -1 if invalid.
       */
!     private static int convertDigit(final char ch, final int base) {
          int digit;
  
          if ('0' <= ch && ch <= '9') {
              digit = ch - '0';
          } else if ('A' <= ch && ch <= 'Z') {
--- 646,656 ----
       * @param ch   Character to convert.
       * @param base Numeric base.
       *
       * @return The converted digit or -1 if invalid.
       */
!     protected static int convertDigit(final char ch, final int base) {
          int digit;
  
          if ('0' <= ch && ch <= '9') {
              digit = ch - '0';
          } else if ('A' <= ch && ch <= 'Z') {
*** 906,916 ****
      }
  
      /**
       * Scan over a string literal.
       */
!     private void scanString(final boolean add) {
          // Type of string.
          TokenType type = STRING;
          // Record starting quote.
          final char quote = ch0;
          // Skip over quote.
--- 906,916 ----
      }
  
      /**
       * Scan over a string literal.
       */
!     protected void scanString(final boolean add) {
          // Type of string.
          TokenType type = STRING;
          // Record starting quote.
          final char quote = ch0;
          // Skip over quote.
*** 923,932 ****
--- 923,935 ----
          while (!atEOF() && ch0 != quote && !isEOL(ch0)) {
              // Skip over escaped character.
              if (ch0 == '\\') {
                  type = ESCSTRING;
                  skip(1);
+                 if (! isEscapeCharacter(ch0)) {
+                     error(Lexer.message("invalid.escape.char"), STRING, position, limit);
+                 }
                  if (isEOL(ch0)) {
                      // Multiline string literal
                      skipEOL(false);
                      continue;
                  }
*** 977,986 ****
--- 980,999 ----
              }
          }
      }
  
      /**
+      * Is the given character a valid escape char after "\" ?
+      *
+      * @param ch character to be checked
+      * @return if the given character is valid after "\"
+      */
+     protected boolean isEscapeCharacter(final char ch) {
+         return true;
+     }
+ 
+     /**
       * Convert string to number.
       *
       * @param valueString  String to convert.
       * @param radix        Numeric base.
       * @return Converted number.
*** 1022,1032 ****
      }
  
      /**
       * Scan a number.
       */
!     private void scanNumber() {
          // Record beginning of number.
          final int start = position;
          // Assume value is a decimal.
          TokenType type = DECIMAL;
  
--- 1035,1045 ----
      }
  
      /**
       * Scan a number.
       */
!     protected void scanNumber() {
          // Record beginning of number.
          final int start = position;
          // Assume value is a decimal.
          TokenType type = DECIMAL;
  
*** 1581,1591 ****
          }
  
          return null;
      }
  
!     private static String message(final String msgId, final String... args) {
          return ECMAErrors.getMessage("lexer.error." + msgId, args);
      }
  
      /**
       * Generate a runtime exception
--- 1594,1604 ----
          }
  
          return null;
      }
  
!     protected static String message(final String msgId, final String... args) {
          return ECMAErrors.getMessage("lexer.error." + msgId, args);
      }
  
      /**
       * Generate a runtime exception