322129 - Regular expression pattern /[]]/ not match right square bracket.

Status: RESOLVED DUPLICATE of bug 272395

(Core :: JavaScript Engine, defect)

Description

[Anthony Howe]

User-Agent:       Mozilla/5.0 (Windows; U; Windows NT 5.1; en; rv:1.8) Gecko/20051111 Firefox/1.5
Build Identifier: Mozilla/5.0 (Windows; U; Windows NT 5.1; en; rv:1.8) Gecko/20051111 Firefox/1.5

JavaScript regular expressions are based on Perl compatible regular expressions, which in turn are based on POSIX extended regular expressions. The pattern:

  /[]]/

should match a right square bracket in a string like "text [text] text". The pattern fails to match. See Single Unix Specification, chapter 9.3.5 RE Bracket Expression, point 1, paragraph 1:

http://www.opengroup.org/onlinepubs/009695399/basedefs/xbd_chap09.html#tag_09_03_05

It would appear that the pattern:

  /[\]]/

will match a right square bracket, but is not standard nor historical practice with respect to regular expressions.

I found this while trying to perform a replacement to quote RE special characters:

  var quoted = string.replace(/([][{}().?/\+*^$|])/g, "\\$1");

The current workaround is to escape the right square bracket within character class:

  var quoted = string.replace(/([\][{}().?/\+*^$|])/g, "\\$1");


Reproducible: Always

Steps to Reproduce:

Comment 1

[Jesse Ruderman]

*** This bug has been marked as a duplicate of 272395 ***