659894 - Firefox 3.6 is the only browser that treats the text "INF" as a number (same for the text INFINITY)

Status: RESOLVED FIXED

(Core :: JavaScript Engine, defect)

Description

[jeanyce]

User-Agent:       Mozilla/5.0 (Windows NT 6.1; WOW64) AppleWebKit/534.24 (KHTML, like Gecko) Chrome/11.0.696.68 Safari/534.24
Build Identifier: 3.6.17

Chrome          isNaN("INF") : true
Chrome Canary   isNaN("INF") : true
IE9             isNaN("INF") : true
IE8             isNaN("INF") : true
IE7             isNaN("INF") : true
IE6             isNaN("INF") : true
Firefox 4       isNaN("INF") : true
Firefox 3.6     isNaN("INF") : false
Firefox 2       isNaN("INF") : true

Reproducible: Always

Steps to Reproduce:
1. Type javascript:alert(isNaN("INF")) in the URL bar and press ENTER

Actual Results:  
2. Firefox 3.6 will display false
3. All other browsers display true

Expected Results:  
true (the String "INF" should not be treated like a number)

Comment 1

[Boris Zbarsky [:bzbarsky]]

I suspect this is wontfix unless there's a clear security or major compatibility (as in, actual major sites broken) issue here.

Comment 2

[j.j.]

Firefox 3.5     isNaN("INF") : false
Firefox 3.0     isNaN("INF") : true

Comment 3

[Cork]

Just to have it documented:

Caused by bug 384244 (Firefox 3.1a2pre 2008-08-06)
http://hg.mozilla.org/mozilla-central/rev/1b24f8e54d1b

Fixed by bug 613492 (Firefox 4.0b8pre 2010-11-26)
http://hg.mozilla.org/tracemonkey/rev/222c29336422

Comment 4

[Cork]

bah the ref links is mixed up.. its 

Caused by bug 384244 (Firefox 3.1a2pre 2008-08-06)
http://hg.mozilla.org/tracemonkey/rev/222c29336422

Fixed by bug 613492 (Firefox 4.0b8pre 2010-11-26)
http://hg.mozilla.org/mozilla-central/rev/1b24f8e54d1b

Comment 5

[j.j.]

This is FIXED in Fx4 (and WONTFIX in Fx3.6)