712128 - Irremovable whitespace on textareas

Status: RESOLVED DUPLICATE of bug 157846

(Core :: DOM: Editor, defect)

Description

[Alex Henrie]

Attachment: Textarea rendering test.html

User Agent: Mozilla/5.0 (Ubuntu; X11; Linux x86_64; rv:8.0) Gecko/20100101 Firefox/8.0
Build ID: 20111115183541

Steps to reproduce:

Firefox adds extra whitespace to textarea elements. This whitespace is not removable even by setting margin:0 and padding:0. To demonstrate the problem, I made a simple test case where black text in a textarea is positioned exactly on top of red text in an identically styled div. In a correct rendering, the black text will hide the red text, and indeed this is what happens in Chromium. In Firefox, the red text is out of alignment with the black text and shows through.

This bug is a problem for Javascript-based source code editors which behave much like the test case. For example, EditArea includes a hack for Firefox on lines 213-218 of http://editarea.svn.sourceforge.net/viewvc/editarea/trunk/edit_area/edit_area.js?revision=30&view=markup but even this hack does not fix the problem in all circumstances or on all platforms.

Comment 1

[Alex Henrie]

Attachment: Chromium rendering

Comment 2

[Alex Henrie]

Attachment: Firefox Linux rendering

Comment 3

[Alex Henrie]

Attachment: Firefox Windows rendering

Comment 4

[j.j.]

Comment on attachment 582950 [details]
Textarea rendering test.html

Confirming on trunk

Comment 5

[Boris Zbarsky [:bzbarsky]]

> In a correct rendering,

There is no spec defining rendering of text controls.

The space is there because it's needed to match IE and WebKit behavior in other cases.  Removing it requires implementing a non-CSS scrolling mechanism for textareas.  There are existing bugs on that, but rewriting the entire textarea layout implementation around this is a low priority.

Comment 6

[j.j.]

>  There are existing bugs on that

I found bug 33654, bug 73817, bug 157846 but none seems related to this issue.