256798 - JS regexp zero-width positive lookahead broken by bug 254296's patch

Status: VERIFIED FIXED

(Core :: JavaScript Engine, defect, P1)

Description

[Brendan Eich [:brendan]]

The patch for bug 254296 regressed zero-width positive lookehead assertions:

js> /(?:(a)+)/("baaaa")
aaaa,a
js> /(?=(a+))/("baaabac")
,aaa
js> /b(?=(a+))/("baaabac")
b,aaa
js> /b(?=(b+))/("baaabac")
null

The last case should return ["b", "b"].

Must-fix for branches and trunk.

/be

Comment 1

[Brendan Eich [:brendan]]

Attachment: fix

for a(?=b), we want to fail fast if SimpleMatch fails, whether or not it
consumed the entire zero-width assertion.  Not so for (?!), which was fixed
last time.

/be

Comment 2

[Mike Shaver (:shaver -- probably not reading bugmail closely)]

Comment on attachment 157203 [details] [diff] [review]
fix

Curses!  r=shaver

Comment 3

[chris hofmann]

Comment on attachment 157203 [details] [diff] [review]
fix

a=chofmann for aviary and 1.7.3

Comment 4

[Brendan Eich [:brendan]]

Fixed on trunk and branches.

/be

Comment 5

[chris hofmann]

Comment on attachment 157203 [details] [diff] [review]
fix

a=chofmann for aviary and 1.7.3

Comment 6

[Bob Clary [:bc] (inactive)]

Attachment: js1_5/Regress/regress-256798.js

thanks to be

Comment 7

[Bob Clary [:bc] (inactive)]

js1_5/Regress/regress-256798.js checked in.

Comment 8

[Bob Clary [:bc] (inactive)]

javascript:/b(?=(b+))/.exec("baaabac") + '' returns 'null' instead of 'b,b' in
sm 1.7.6 and trunk, ff 1.0x and trunk. Should this be reopened?

Comment 9

[Brendan Eich [:brendan]]

(In reply to comment #8)
> javascript:/b(?=(b+))/.exec("baaabac") + '' returns 'null' instead of 'b,b' in
> sm 1.7.6 and trunk, ff 1.0x and trunk. Should this be reopened?

Please file a new bug or bugs.  It looks like a bunch of stuff to-do with zero-width positive and negative lookahead is broken:

js> /(?!a)b/('zzzabzzz')
ab

mrbkap should take these bug(s) -- he didn't make this mess but he can fix it.

/be

Comment 10

[Brendan Eich [:brendan]]

(In reply to comment #9)

See bug 322836.

/be

Comment 11

[Bob Clary [:bc] (inactive)]

verified fixed.