217268 - Number.toFixed() gives wrong result in 1.5R4.1

Status: RESOLVED FIXED

(Rhino Graveyard :: Core, defect)

Description

[Larry Blair]

User-Agent:       Mozilla/5.0 (Windows; U; Windows NT 5.0; en-US; rv:1.3) Gecko/20030312
Build Identifier: Mozilla/5.0 (Windows; U; Windows NT 5.0; en-US; rv:1.3) Gecko/20030312

For certain values, Number.toFixed() gives a wrong result.

Reproducible: Always

Steps to Reproduce:
1. java Shell
2. js> Number(123.223456789).toFixed(12);
Actual Results:  
123.223456788900

Expected Results:  
123.223456789000

Comment 1

[Phil Schwartau]

cc'ing Igor -

Comment 2

[Larry Blair]

I've tracked it down to org.mozilla.javascript.DToA.JS_dtoa(), possibly the most
arcane and unfathomable code I've ever seen.  Good luck to whoever tries to fix
this...

Comment 3

[Phil Schwartau]

For convenience, here is the corresponding code from SpiderMonkey:
http://lxr.mozilla.org/mozilla/source/js/src/jsdtoa.c

Comment 4

[Igor Bukanov]

Attachment: Fix for DToA.roundOff

The reason for the bug is that after cutting all trailing '9' DToA.roundOff
appended to the buffer last digit plus one instead of setting the last
character to that value.

Comment 5

[Igor Bukanov]

I committed the fix

Comment 6

[Igor Bukanov]

*** Bug 217965 has been marked as a duplicate of this bug. ***

Comment 7

[Igor Bukanov]

Trageting as resolved against 1.5R5