Bug 49782

Summary:	255 stepUp()s for step=0.00392156863 is not 1.
Product:	WebKit	Reporter:	Dai Mikurube <dmikurube>
Component:	WebCore Misc.	Assignee:	Nobody <webkit-unassigned>
Status:	RESOLVED CONFIGURATION CHANGED
Severity:	Normal	CC:	ahmad.saleem792, annevk, dmikurube
Priority:	P2
Version:	528+ (Nightly build)
Hardware:	PC
OS:	All

Description Dai Mikurube 2010-11-18 19:56:09 PST

How to reproduce:
1. <input type="number" min="0" value="0" step="0.00392156863" />
2. stepUp() for 255 times.

Expected:
1 (from an example at HTML5 spec. : 4.10.7.2.11 The step attribute)

Actual:
1.00000000065


Discussed at the bug 48976.

Hints:
I found we can calculate it if completely using IEEE 754 single precision numbers.
Re-considering precisions in calculation and printing may help.

Another option:
Re-consider the spec.

Comment 1 Ahmad Saleem 2024-01-02 09:15:38 PST

Chrome Canary 122 - 1.00000000065

Safari 17.2.1 - 1.00000000065

Firefox Nightly 123 - 1.00000000065

I didn't counted 255 clicks, I just moved using 'Up' key till reaching near 0.99xx to 1.xx.

I think web-spec is for 'double precision' number, so we can mark this as 'RESOLVED CONFIGURATION CHANGED'.