From 7f36b525401817121fac79b7005a7f6a86862639 Mon Sep 17 00:00:00 2001
From: "ricow@chromium.org"
 <ricow@chromium.org@ce2b1a6d-e550-0410-aec6-3dcde31c8c00>
Date: Wed, 17 Aug 2011 08:22:41 +0000
Subject: [PATCH] Revert 8942 "Make scanner not accept invalid unicode escapes
 in identifiers"

This is causing webkit failures, reverting until we figure out if this is a V8 regression or wrong test expectations.
Review URL: http://codereview.chromium.org/7669017

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@8947 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
---
 src/scanner-base.cc                  | 25 +++++++-------------
 src/scanner-base.h                   |  2 +-
 test/mjsunit/regress/regress-1620.js | 35 ----------------------------
 3 files changed, 10 insertions(+), 52 deletions(-)
 delete mode 100644 test/mjsunit/regress/regress-1620.js

diff --git a/src/scanner-base.cc b/src/scanner-base.cc
index 6da6b59e17..848980372d 100644
--- a/src/scanner-base.cc
+++ b/src/scanner-base.cc
@@ -41,12 +41,12 @@ Scanner::Scanner(UnicodeCache* unicode_cache)
     : unicode_cache_(unicode_cache) { }
 
 
-  uc32 Scanner::ScanHexNumber(int expected_length) {
-  ASSERT(expected_length <= 4);  // prevent overflow
+uc32 Scanner::ScanHexEscape(uc32 c, int length) {
+  ASSERT(length <= 4);  // prevent overflow
 
   uc32 digits[4];
   uc32 x = 0;
-  for (int i = 0; i < expected_length; i++) {
+  for (int i = 0; i < length; i++) {
     digits[i] = c0_;
     int d = HexValue(c0_);
     if (d < 0) {
@@ -54,11 +54,12 @@ Scanner::Scanner(UnicodeCache* unicode_cache)
       // should be illegal, but other JS VMs just return the
       // non-escaped version of the original character.
 
-      // Push back digits that we have advanced past.
+      // Push back digits read, except the last one (in c0_).
       for (int j = i-1; j >= 0; j--) {
         PushBack(digits[j]);
       }
-      return unibrow::Utf8::kBadChar;
+      // Notice: No handling of error - treat it as "\u"->"u".
+      return c;
     }
     x = x * 16 + d;
     Advance();
@@ -638,17 +639,9 @@ void JavaScriptScanner::ScanEscape() {
     case 'n' : c = '\n'; break;
     case 'r' : c = '\r'; break;
     case 't' : c = '\t'; break;
-    case 'u' : {
-      c = ScanHexNumber(4);
-      if (c == static_cast<uc32>(unibrow::Utf8::kBadChar)) c = 'u';
-      break;
-    }
+    case 'u' : c = ScanHexEscape(c, 4); break;
     case 'v' : c = '\v'; break;
-    case 'x' : {
-      c = ScanHexNumber(2);
-      if (c == static_cast<uc32>(unibrow::Utf8::kBadChar)) c = 'x';
-      break;
-    }
+    case 'x' : c = ScanHexEscape(c, 2); break;
     case '0' :  // fall through
     case '1' :  // fall through
     case '2' :  // fall through
@@ -810,7 +803,7 @@ uc32 JavaScriptScanner::ScanIdentifierUnicodeEscape() {
   Advance();
   if (c0_ != 'u') return unibrow::Utf8::kBadChar;
   Advance();
-  uc32 c = ScanHexNumber(4);
+  uc32 c = ScanHexEscape('u', 4);
   // We do not allow a unicode escape sequence to start another
   // unicode escape sequence.
   if (c == '\\') return unibrow::Utf8::kBadChar;
diff --git a/src/scanner-base.h b/src/scanner-base.h
index da74757648..3e1772a3d2 100644
--- a/src/scanner-base.h
+++ b/src/scanner-base.h
@@ -419,7 +419,7 @@ class Scanner {
     }
   }
 
-  uc32 ScanHexNumber(int expected_length);
+  uc32 ScanHexEscape(uc32 c, int length);
 
   // Return the current source position.
   int source_pos() {
diff --git a/test/mjsunit/regress/regress-1620.js b/test/mjsunit/regress/regress-1620.js
deleted file mode 100644
index 8deed1e923..0000000000
--- a/test/mjsunit/regress/regress-1620.js
+++ /dev/null
@@ -1,35 +0,0 @@
-// Copyright 2011 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
-//       with the distribution.
-//     * Neither the name of Google Inc. nor the names of its
-//       contributors may be used to endorse or promote products derived
-//       from this software without specific prior written permission.
-//
-// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
-// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
-// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
-// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
-// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
-// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
-// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
-// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
-// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
-// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
-// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
-
-// See: http://code.google.com/p/v8/issues/detail?id=1620
-
-assertThrows("var \\u\\u\\u = 42;");
-assertThrows("var \\u41 = 42;");
-assertThrows("var \\u123 = 42;");
-eval("var \\u1234 = 42;");
-assertEquals(42, eval("\u1234"));
-assertThrows("var uuu = 42; var x = \\u\\u\\u");