[regexp] disallow regexp property class shorthand syntax for single char.

src/regexp/regexp-parser.cc

 // Copyright 2016 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "src/regexp/regexp-parser.h"
 
 #include "src/char-predicates-inl.h"
 #include "src/factory.h"
 #include "src/isolate.h"
 #include "src/objects-inl.h"
@@ skipping 894 matching lines @@
     }
     DCHECK_EQ(U_ZERO_ERROR, ec);
     DCHECK_EQ(0, item_result);
   }
   uset_close(set);
   return success;
 }
 
 bool RegExpParser::ParsePropertyClass(ZoneList<CharacterRange>* result) {
   // Parse the property class as follows:
-  // - \pN with a single-character N is equivalent to \p{N}
   // - In \p{name}, 'name' is interpreted
   //   - either as a general category property value name.
   //   - or as a binary property name.
   // - In \p{name=value}, 'name' is interpreted as an enumerated property name,
   //   and 'value' is interpreted as one of the available property value names.
   // - Aliases in PropertyAlias.txt and PropertyValueAlias.txt can be used.
   // - Loose matching is not applied.
   List<char> first_part;
   List<char> second_part;
   if (current() == '{') {
     // Parse \p{[PropertyName=]PropertyNameValue}
     for (Advance(); current() != '}' && current() != '='; Advance()) {
       if (!has_next()) return false;
       first_part.Add(static_cast<char>(current()));
     }
     if (current() == '=') {
       for (Advance(); current() != '}'; Advance()) {
         if (!has_next()) return false;
         second_part.Add(static_cast<char>(current()));
       }
       second_part.Add(0);  // null-terminate string.
     }
-  } else if (current() != kEndMarker) {
-    // Parse \pN, where N is a single-character property name value.
-    first_part.Add(static_cast<char>(current()));
   } else {
     return false;
   }
   Advance();
   first_part.Add(0);  // null-terminate string.
 
   if (second_part.is_empty()) {
     // First attempt to interpret as general category property value name.
     const char* name = first_part.ToConstVector().start();
     if (LookupPropertyValueName(UCHAR_GENERAL_CATEGORY_MASK, name, result,
@@ skipping 610 matching lines @@
     return false;
   }
   terms_.Add(new (zone()) RegExpQuantifier(min, max, quantifier_type, atom),
              zone());
   LAST(ADD_TERM);
   return true;
 }
 
 }  // namespace internal
 }  // namespace v8