297172 - [FIX]Select box bug when dynamicly enabling and disabling multiple selects.

Status: RESOLVED FIXED

(Core :: Layout: Form Controls, defect, P3)

Description

[Jeppe Dyrby]

User-Agent:       Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.8b2) Gecko/20050527 Firefox/1.0+
Build Identifier: Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.8b2) Gecko/20050527 Firefox/1.0+

When dynamicly changing the state of a select box (<select>) with javascript
from a list with multiple selections, to a single selection dropdown box, the
selected items (multiple) are still selected when the box drops down. When the
mouse hovers over some elements, they seese to be selected.
I believe this is a bug, because it should not be possible to have multiple
selections in a dropdown box. It should, if at all, only be the first option
that would be selected if such a change should happend.

This was in Deer Park Alpha 1, not tested in other versions, or on other
platforms. An example shall be made ASAP.

Reproducible: Always

Steps to Reproduce:
1. Make select box with multiple selections.
2. Change the state with javascript, while having selected multiple options.
3. Select the box, to make it drop down, see what happends.

Actual Results:  
The multiple selections from the list, wich allows this, is transferred to the
single selection dropdown box.

Expected Results:  
Only one should have been selected.

An example page will be made ASAP.

Comment 1

[Jeppe Dyrby]

Example page.
Mail me if this page for some unknown reason disapears.

http://bravoo.dk/playground/bug297172.html

Comment 2

[Steve England [:stevee]]

Attachment: reporter's testcase from URL

Comment 3

[Adam Guthrie]

Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.8b2) Gecko/20050609
Firefox/1.0+ ID:2005060918

WFM. The selected items are retained no matter how many times you check "change
select box" and no matter how many items you have selected in the dropdown menu.

Comment 4

[Boris Zbarsky [:bzbarsky]]

Attachment: Proposed patch

Comment 5

[Peter Van der Beken [:peterv]]

Comment on attachment 197270 [details] [diff] [review]
Proposed patch

>Index: content/html/content/src/nsHTMLSelectElement.cpp
>===================================================================

>+    PRInt32 selectedIndex;
>+    GetSelectedIndex(&selectedIndex);
>+    if (selectedIndex > -1) {

Any reason to not use mSelectedIndex?

Comment 6

[Boris Zbarsky [:bzbarsky]]

Fixed on trunk.