Revert 5911 (RegExp fail on invalid range syntax).

src/parser.cc

Index: src/parser.cc
diff --git a/src/parser.cc b/src/parser.cc
index 160f0f784489a409ab49d44b18edfc16dacdcc3b..fd93aae4241d7494dc26522ca4904081e746c4eb 100644
--- a/src/parser.cc
+++ b/src/parser.cc
@@ -4452,7 +4452,6 @@ CharacterRange RegExpParser::ParseClassAtom(uc16* char_class) {
 RegExpTree* RegExpParser::ParseCharacterClass() {
   static const char* kUnterminated = "Unterminated character class";
   static const char* kRangeOutOfOrder = "Range out of order in character class";
-  static const char* kInvalidRange = "Invalid character range";
 
   ASSERT_EQ(current(), '[');
   Advance();
@@ -4461,28 +4460,12 @@ RegExpTree* RegExpParser::ParseCharacterClass() {
     is_negated = true;
     Advance();
   }
-  // A CharacterClass is a sequence of single characters, character class
-  // escapes or ranges. Ranges are on the form "x-y" where x and y are
-  // single characters (and not character class escapes like \s).
-  // A "-" may occur at the start or end of the character class (just after
-  // "[" or "[^", or just before "]") without being considered part of a
-  // range. A "-" may also appear as the beginning or end of a range.
-  // I.e., [--+] is valid, so is [!--].
-
   ZoneList<CharacterRange>* ranges = new ZoneList<CharacterRange>(2);
   while (has_more() && current() != ']') {
     uc16 char_class = 0;
     CharacterRange first = ParseClassAtom(&char_class CHECK_FAILED);
     if (char_class) {
       CharacterRange::AddClassEscape(char_class, ranges);
-      if (current() == '-') {
-        Advance();
-        ranges->Add(CharacterRange::Singleton('-'));
-        if (current() != ']') {
-          ReportError(CStrVector(kInvalidRange) CHECK_FAILED);
-        }
-        break;
-      }
       continue;
     }
     if (current() == '-') {
@@ -4498,7 +4481,10 @@ RegExpTree* RegExpParser::ParseCharacterClass() {
       }
       CharacterRange next = ParseClassAtom(&char_class CHECK_FAILED);
       if (char_class) {
-        ReportError(CStrVector(kInvalidRange) CHECK_FAILED);
+        ranges->Add(first);
+        ranges->Add(CharacterRange::Singleton('-'));
+        CharacterRange::AddClassEscape(char_class, ranges);
+        continue;
       }
       if (first.from() > next.to()) {
         return ReportError(CStrVector(kRangeOutOfOrder) CHECK_FAILED);