158071 - Input undo/redo buffers cleared after Javascript changes to input values

Status: RESOLVED FIXED

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

Description

[leonard]

From Bugzilla Helper:
User-Agent: Mozilla/5.0 (Windows; U; Windows NT 5.0; en-US; rv:1.1a+) Gecko/20020715
BuildID:    2002071508

I noticed this implementing a rich text-edit control (see URL), but this problem
affects any input manipulated by JavaScript.

Firstly, a Javascript input.value change is captured by the undo buffer, and
secondly, if an input.value is called, it will actually clear the undo/redo
buffer for that input.

That's bad.

Reproducible: Always
Steps to Reproduce:
1. Go to a page with an input/textarea
2. Type some stuff, delete some stuff in input/texarea.  Make sure the undo/redo
buffer is working
3. Type: 'javascript:document.getElementsByTagName("input")[0].value = "foo";
void 0' in the URL bar (replace input w/ textarea if it's a textarea)
4. Try undoing the change or any of your previous changes in that input/texarea.
 You can't.

Actual Results:  Input/textarea's value is 'foo'.  This change cannot be undone.

Expected Results:  Mozilla should allow that action to be undone, and should not
clear the undo/redo buffer.  A javascript value change should be equivalent to a
single typing action's change.

IE has the expected (correct) behavior.

Comment 1

[Boris Zbarsky [:bzbarsky]]

would be nice.....

Comment 2

[John Keiser (jkeiser)]

to default owner

Comment 3

[Martijn Wargers (dead)]

I don't know anything of c, but isn't this explicitly programmed this way here:
http://lxr.mozilla.org/seamonkey/source/layout/html/forms/src/nsTextControlFrame.cpp#2159
So by removing these lines which disable/enable undo, the bug would be fixed
(not if I'm wrong off course, then sorry for the spam)

Comment 4

[Martijn Wargers (dead)]

Attachment: Quick testcase to see that in current situation pressing undo/redo doesn't work

Comment 5

[Martijn Wargers (dead)]

Attachment: Patch to turn on again the undo/redo buffers

Just deleting these lines seem to make this work in my homebrewn build.

Comment 6

[Brian Ryner (not reading)]

Comment on attachment 145575 [details] [diff] [review]
Patch to turn on again the undo/redo buffers

Seems ok, and I can't find any trail that tells me why the code was written
this way.  Over to dbaron for a second opinion though.

Comment 7

[Martijn Wargers (dead)]

So the patch got review+ and superreview+. Isn't it ready then to be checked in?
(Sorry for sounding so ignorant)

Comment 8

[Boris Zbarsky [:bzbarsky]]

(In reply to comment #7)
> So the patch got review+ and superreview+. Isn't it ready then to be checked in?

It is, but you need to get someone to do that.  Note that dbaron and bryner are
not cced on the bug, so they didn't see that question.

I just checked in the patch to the 1.8a trunk.

Comment 9

[Martijn Wargers (dead)]

Could this get in the aviary branch, please? I don't think there is any risk
with this patch and with this patch, Firefox would be more friendly to
bb/Blogger forms. 

Comment 10

[Phil Ringnalda (:philor)]

*** Bug 274395 has been marked as a duplicate of this bug. ***