191479 - regular expressions like /(x|y){n,}/ are failed in some cases

Status: RESOLVED FIXED

(Core :: JavaScript Engine, defect)

Description

[Alexander Grimalovsky]

Mozilla trunk build ID: 2002122708 on Windows 2000

Take a look at following example:

Regular expression: /(\d|\d\-|\d\s){2,}/ 
Matched string: 12 3 45

This expression matches given string. But after small improvement:
/(\d|\d\-|\d\s){4,}/ 

 It isn't match it anymore, while it should (and it works in IE5.01 for
example). It also starts to match this string again if {4,} quantifier is
replaced with '+' quantifier or if search condition is rewritten as (\d\s?).

 I've prepare testcase to demonstrate a problem.

Comment 1

[Alexander Grimalovsky]

Attachment: Testcase to demonstrate a problem

Comment 2

[Phil Schwartau]

Testcase added to JS testsuite:

      mozilla/js/tests/ecma_3/RegExp/regress-191479.js


This contains Alexander's tests above. In addition, I experimented
by reversing the order of the operands, and added cases where the
quantifiers are non-greedy (by appending ? to them).

All the "expected" outcomes have been verified against the Perl 5 
regular expression engine.

The testcase is passing in the current Rhino shell, which makes me
think this bug is yet another duplicate of the RegExp bug 85721.

However the testcase is not passing for me with the latest patch 
for bug 85721, so perhaps an update is required there - (?)

Comment 3

[rogerl (gone)]

I have updated the patch for bug 85721 to fix these cases.

Comment 4

[Phil Schwartau]

Confirming - with the latest patch for bug 85721, the testcase passes.

Alexander: we'll be finished once the patch for bug 85721 is reviewed
and checked in. This may take some time, however, as it is a complete
rewrite of the regular expression engine -

Comment 5

[Alexander Grimalovsky]

Thank you all for your work and incredible product!

Comment 6

[Brendan Eich [:brendan]]

Fixed with bug 85721.

/be