Issue 2408 in v8: String.prototype.trim() trims 0x200b ZERO WIDTH SPACE

[codesite...@google.com]

Status: New
Owner: ----

New issue 2408 by erik...@google.com: String.prototype.trim() trims
0x200b ZERO WIDTH SPACE
http://code.google.com/p/v8/issues/detail?id=2408

V8 follows JSC in trimming the zero width space (0x200b) in the trim()
method. According to

https://bugs.webkit.org/show_bug.cgi?id=26590

this is following an early draft of the trim() spec, but in the ES5 spec
only a few characters are specified apart from the Unicode space category
(which does not include the zero width space).

Firefox follows ES5 on this one.

Repro:

alert("\u200b".trim().length); // Should alert "1".

V8 also strips 0x85, the NEL (next line) character. It is alone in
this,but 0x85 is not mentioned in runtime.cc so it must be from the unicode
tables, which may be out of date.

Search for 200b in runtime.cc.

[codesite...@google.com]

Updates:
Status: Assigned
Owner: mstar...@chromium.org
Cc: christia...@gmail.com
Labels: ES5

Comment #1 on issue 2408 by erik.corry: String.prototype.trim() trims

0x200b ZERO WIDTH SPACE
http://code.google.com/p/v8/issues/detail?id=2408

(No comment was entered for this change.)

[codesite...@google.com]

Updates:
Labels: Type-Bug Priority-Medium

Comment #2 on issue 2408 by mstar...@chromium.org:

String.prototype.trim() trims 0x200b ZERO WIDTH SPACE
http://code.google.com/p/v8/issues/detail?id=2408

So I checked the Unicode 6.2 character database and the following
characters belong to the "Zs" category.

0020;SPACE;Zs;0;WS;;;;;N;;;;;
00A0;NO-BREAK SPACE;Zs;0;CS;<noBreak> 0020;;;;N;NON-BREAKING SPACE;;;;
1680;OGHAM SPACE MARK;Zs;0;WS;;;;;N;;;;;
180E;MONGOLIAN VOWEL SEPARATOR;Zs;0;WS;;;;;N;;;;;
2000;EN QUAD;Zs;0;WS;2002;;;;N;;;;;
2001;EM QUAD;Zs;0;WS;2003;;;;N;;;;;
2002;EN SPACE;Zs;0;WS;<compat> 0020;;;;N;;;;;
2003;EM SPACE;Zs;0;WS;<compat> 0020;;;;N;;;;;
2004;THREE-PER-EM SPACE;Zs;0;WS;<compat> 0020;;;;N;;;;;
2005;FOUR-PER-EM SPACE;Zs;0;WS;<compat> 0020;;;;N;;;;;
2006;SIX-PER-EM SPACE;Zs;0;WS;<compat> 0020;;;;N;;;;;
2007;FIGURE SPACE;Zs;0;WS;<noBreak> 0020;;;;N;;;;;
2008;PUNCTUATION SPACE;Zs;0;WS;<compat> 0020;;;;N;;;;;
2009;THIN SPACE;Zs;0;WS;<compat> 0020;;;;N;;;;;
200A;HAIR SPACE;Zs;0;WS;<compat> 0020;;;;N;;;;;
202F;NARROW NO-BREAK SPACE;Zs;0;CS;<noBreak> 0020;;;;N;;;;;
205F;MEDIUM MATHEMATICAL SPACE;Zs;0;WS;<compat> 0020;;;;N;;;;;
3000;IDEOGRAPHIC SPACE;Zs;0;WS;<wide> 0020;;;;N;;;;;

On top of that ES5.1 specifies the following characters explicitly to be
WhiteSpace or LineTerminator.

0009, Tab
000A, Line Feed
000B, Vertical Tab
000D, Carriage Return
000C, Form Feed
0020, Space
00A0, No-break space
2028, Line separator
2029, Paragraph separator
FEFF, Byte Order Mark

I still need to figure out where the NEL character is coming from.

[codesite...@google.com]

Comment #3 on issue 2408 by mstar...@chromium.org:

String.prototype.trim() trims 0x200b ZERO WIDTH SPACE
http://code.google.com/p/v8/issues/detail?id=2408

Yep, both Unicode 6.1 (which we are currently based on) and Unicode 6.2
(the most recent) mark 0x0085 as having the "White_Space" property but not
being in the "Zs" category. So actually the problem is that our Unicode
tables are based on properties instead of categories. But 0x0085 is the
only character where that's a problem. So the quick fix is to just special
case the for String.prototype.trim() as we already do.

[codesite...@google.com]

Updates:
Status: Fixed

Comment #4 on issue 2408 by yan...@chromium.org: String.prototype.trim()

trims 0x200b ZERO WIDTH SPACE
http://code.google.com/p/v8/issues/detail?id=2408

Fixed in r19196.

--
You received this message because this project is configured to send all
issue notifications to this address.
You may adjust your notification preferences at:
https://code.google.com/hosting/settings

[codesite...@google.com]

Comment #5 on issue 2408 by mathi...@opera.com: String.prototype.trim()

trims 0x200b ZERO WIDTH SPACE
http://code.google.com/p/v8/issues/detail?id=2408

Fix was reverted: https://code.google.com/p/v8/source/detail?r=19199

[codesite...@google.com]

Updates:
Status: Assigned
Owner: yan...@chromium.org

Comment #6 on issue 2408 by yan...@chromium.org: String.prototype.trim()

trims 0x200b ZERO WIDTH SPACE
http://code.google.com/p/v8/issues/detail?id=2408

Right. Improved CL coming up.

[codesite...@google.com]

Updates:
Status: Fixed

Comment #7 on issue 2408 by yan...@chromium.org: String.prototype.trim()

trims 0x200b ZERO WIDTH SPACE
http://code.google.com/p/v8/issues/detail?id=2408

Fixed in r19222.