Fix V8 bug 1084

src/scanner-base.cc

 // Copyright 2010 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 81 matching lines @@
     Advance();
   }
 
   return x;
 }
 
 
 // Octal escapes of the forms '\0xx' and '\xxx' are not a part of
 // ECMA-262. Other JS VMs support them.
 uc32 Scanner::ScanOctalEscape(uc32 c, int length) {
-  octal_pos_ = source_pos() - 1;     // Already advanced
   uc32 x = c - '0';
-  for (int i = 0; i < length; i++) {
+  int i = 0;
+  for (; i < length; i++) {
     int d = c0_ - '0';
     if (d < 0 || d > 7) break;
     int nx = x * 8 + d;
     if (nx >= 256) break;
     x = nx;
     Advance();
   }
+  // Anything excelt '\0' is an octal escape sequence, illegal in strict mode.
+  // Remember the position of octal escape sequences so that better error
+  // can be reported later (in strict mode).
+  if (c != '0' || i > 0) {
+    octal_pos_ = source_pos() - i - 1;     // Already advanced
+  }
   return x;
 }
 
 
 // ----------------------------------------------------------------------------
 // JavaScriptScanner
 
 JavaScriptScanner::JavaScriptScanner() : Scanner() {}
 
 
@@ skipping 785 matching lines @@
       if (MatchKeywordStart(input, "with", 1, Token::WITH)) return;
       break;
     case UNMATCHABLE:
       break;
   }
   // On fallthrough, it's a failure.
   state_ = UNMATCHABLE;
 }
 
 } }  // namespace v8::internal