Bug 23611 - Multiline Javascript comments cause incorrect parsing of following script.
Summary: Multiline Javascript comments cause incorrect parsing of following script.
Alias: None
Product: WebKit
Classification: Unclassified
Component: JavaScriptCore (show other bugs)
Version: 528+ (Nightly build)
Hardware: PC All
: P2 Minor
Assignee: Nobody
URL: http://bugs.ecmascript.org/ticket/414
Keywords: HasReduction, InRadar
Depends on:
Reported: 2009-01-28 21:44 PST by Mike Samuel
Modified: 2011-06-16 18:53 PDT (History)
3 users (show)

See Also:


Note You need to log in before you can comment on or make changes to this bug.
Description Mike Samuel 2009-01-28 21:44:38 PST
Chapter 5.1.2 of the recently approved ES3.1 spec, and the corresponding language from ES 262 say
"A MultiLineComment? (that is, a comment of the form "/* ... */" regardless of whether it spans more than one line) is likewise simply discarded if it contains no line terminator, but if a MultiLineComment? contains one or more line terminators, then it is replaced with a single line terminator, which becomes part of the stream of inputs for the syntactic grammar." 

But the below returns 2 on Safari, when it should return 1.
(function () { a: for (;;) { for (;;) { break/*
 */a; } return 1; } return 2; })()

By way of explanation, the comment between break and a should introduce a newline, which since break is a restricted production, should cause it to break without a label (out of the inner loop), instead of breaking to the label a (the outer loop).
Comment 1 Mark Rowe (bdash) 2009-01-28 23:07:49 PST
Comment 2 kangax 2010-02-22 06:01:22 PST
This is still an issue (as of r55043)

A simple example demonstrating WebKit non-conformance in regards to replacing LineTerminator-containing multiline comment with LineTerminator:


Expected: `undefined` Actual: `1`
Comment 3 kangax 2010-03-04 11:29:11 PST
Still happens in rev 55516.
Comment 4 kangax 2010-10-26 08:11:27 PDT
Oh wow. This one is still in r70429.
Comment 5 Gavin Barraclough 2011-06-16 18:53:45 PDT
Fixed in r89100