1068488 - datalist-size breaks on fast changes

Status: UNCONFIRMED

(Core :: Layout: Form Controls, defect)

Description

[eric]

Attachment: test.html

User Agent: Mozilla/5.0 (X11; Ubuntu; Linux x86_64; rv:31.0) Gecko/20100101 Firefox/31.0
Build ID: 20140715214327

Steps to reproduce:

I wanted to use the datalist-element to give the user some suggestions, which again are loaded on every "keyup" from the server.
For this, before every ajax-call, the datalist gets cleaned up (all childs get removed) and then refilled with the servers response.
(Cleaning up immediately before i insert the new data does not change the behaviour)

This means there are a lot of changes on the datalist in a short period of time. (<-- really important!)

To reproduce:
 1. open the attachment
 2 [review]. press a random key again and again really fast
The javascript will then generate 0 to 9 options-elements per "keyup" in the datalist with the value of the input + a random number to simulate the server.

I'm using Firefox 31 from the official ubuntu 14.04 package-repository.


Actual results:

The size of the datalist gets fixed and will not longer change.
So you have then maybe 5 entries but only one is showed and you need to scroll.
This fixed size is then the same for all datalists (also those of normal autocompletion) in the whole browser and will not change before you restart firefox.

Also if the size gets fixed at, for example 4, and you have only one option in the datalist, the other 3 rows are shown but have no content (like selects with a size > 1).


Expected results:

The datalist should grow in size as it gets more elements, till the maximum size.
I should not need to scroll just for 3 entries (because the size of the datalist is fixed at 1 for example).

Comment 1

[Loic]

Attachment: screencast-bug1068488.mp4

I tested with FF32 on Win 7, the testcase works. The size of the drop-down list of <datalist> is updated at each random key pressed. See my screencast.

Comment 2

[branciat]

Bug is also in the actual version (38.0). 
HTML5 is released now.