453549 - setting options.length results in "setting a property that has only a getter"

Status: RESOLVED WORKSFORME

(Core :: DOM: Core & HTML, defect)

Description

[crisp]

User-Agent:       Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.9.1b1pre) Gecko/20080903034741 Minefield/3.1b1pre
Build Identifier: Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.9.1b1pre) Gecko/20080903034741 Minefield/3.1b1pre

Although the DOM level 2 specification allows implementations to make the length property of an HTMLOptionsCollection readonly the setting of this property is necessary for backcompat and defining it as readonly in Minefield 3.1 is a regression which will break many sites.

Reproducible: Always

Steps to Reproduce:
1. Target a SELECT element in the DOM that has options
2. Set the length property of the select.options collection to 0
Actual Results:  
A javascript error is raised: "setting a property that has only a getter"

Expected Results:  
All associated option-elements should be removed from the SELECT element

Comment 1

[crisp]

Attachment: Testcase that shows the error

Comment 2

[cmtalbert]

Thanks for the testcase that was super helpful.

This looks like a regression, and it looks like it is specific to windows, can't reproduce on mac.  

Works on Firefox 2.0.0.x, 3.0.x.

Works on: Mozilla/5.0 (Windows; U; Windows NT 6.0; en-US; rv:1.9.1b1pre) Gecko/20080830031750 Minefield/3.1b1pre

Fails on: Mozilla/5.0 (Windows; U; Windows NT 6.0; en-US; rv:1.9.1b1pre) Gecko/20080831162801 Minefield/3.1b1pre

The changelog for this is here, but I don't see anything that seems to have caused this: http://hg.mozilla.org/mozilla-central/log/03f2c43195a6

Moving to content, though it might also belong in the widget code.

Comment 3

[Peter Van der Beken [:peterv]]

Not sure what fixed this.