Make line-terminators inside multi-line comments count.

Now follows the specification. Follows WebKit change in revision 89100.

BUG=86431
TEST=regress-892742

Review URL: http://codereview.chromium.org/7184034

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@8317 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

src/scanner-base.cc

@@ -144,7 +144,7 @@ Token::Value JavaScriptScanner::SkipSingleLineComment() {
   // to be part of the single-line comment; it is recognized
   // separately by the lexical grammar and becomes part of the
   // stream of input elements for the syntactic grammar (see
-  // ECMA-262, section 7.4, page 12).
+  // ECMA-262, section 7.4).
   while (c0_ >= 0 && !unicode_cache_->IsLineTerminator(c0_)) {
     Advance();
   }
@@ -160,13 +160,14 @@ Token::Value JavaScriptScanner::SkipMultiLineComment() {
   while (c0_ >= 0) {
     char ch = c0_;
     Advance();
+    if (unicode_cache_->IsLineTerminator(ch)) {
+      // Following ECMA-262, section 7.4, a comment containing
+      // a newline will make the comment count as a line-terminator.
+      has_line_terminator_before_next_ = true;
+    }
     // If we have reached the end of the multi-line comment, we
     // consume the '/' and insert a whitespace. This way all
-    // multi-line comments are treated as whitespace - even the ones
-    // containing line terminators. This contradicts ECMA-262, section
-    // 7.4, page 12, that says that multi-line comments containing
-    // line terminators should be treated as a line terminator, but it
-    // matches the behaviour of SpiderMonkey and KJS.
+    // multi-line comments are treated as whitespace.
     if (ch == '*' && c0_ == '/') {
       c0_ = ' ';
       return Token::WHITESPACE;

test/mjsunit/regress/regress-892742.js

@@ -26,25 +26,23 @@
 // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
 function f() {
-  return/* useless*/1;
+  return/* Counts as non-line-terminating whitespace */1;
 };
 
-
-// According to ECMA-262, this comment should actually be parsed as a
-// line terminator making g() return undefined, but this is not the
-// way it's handled by Spidermonkey or KJS.
+// According to ECMA-262, this comment should be parsed as a
+// line terminator making g() return undefined.
 function g() {
-  return/* useless
+  return/* Counts as line-terminator whitespace.
           */2;
 };
 
 function h() {
-  return// meaningful
+  return// Comment doesn't include line-terminator at end.
       3;
 };
 
 
 assertEquals(1, f());
-assertEquals(2, g());
-assertTrue(typeof h() == 'undefined', 'h');
+assertEquals(undefined, g());
+assertEquals(undefined, h());