951993 - Setting ui.allow_platform_file_picker to false breaks multiple file selection in HTML forms

Status: VERIFIED FIXED

(Toolkit :: General, defect)

Description

[Gary Houston]

Attachment: upload.html

User Agent: Mozilla/5.0 (X11; Ubuntu; Linux x86_64; rv:26.0) Gecko/20100101 Firefox/26.0 (Beta/Release)
Build ID: 20131206145143

Steps to reproduce:

Using Firefox 26 on xubuntu 13.10. Open the attached file "upload.html". Select a couple of files by holding the shift or control keys and note what the form displays. Now change ui.allow_platform_file_picker in about.config and try again.


Actual results:

The same dialog is used regardless of the setting of the variable (I think it's an internal Firefox dialog). When the setting is true, multiple files can be selected and the form displays:

Browse... 2 files selected

When the setting is false, it's still possible to select multiple files, but only one is displayed in the form (and only one will be uploaded, in a real example):

Browse... test1.txt



Expected results:

Setting the variable to true should allow the default system dialog to be used (in xubuntu, I guess that would be the one used by Chrome, or the default text editor, Mousepad.)

However even if a system dialog isn't available in xubuntu, changing the setting shouldn't break the selection of multiple files in an HTML form.

It's possible that this is a bug recently introduced into Firefox. I discovered recently that uploading multiple files didn't work anymore, and traced it to that variable, which was false. However I don't remember changing the value of that variable recently.

Comment 1

[Gary Houston]

It seems that it is using a different dialog depending on the setting of ui.allow_platform_file_picker, as expected. I'm also getting a warning about mMode being undefined in nsFilePicker.js, and this file was changed a few months ago. I'll add a patch that seems to fix it.

Comment 2

[Gary Houston]

Attachment: Proposed patch to fix the problem.

Comment 3

[Gary Houston]

Attachment: patch with added check in info.

Comment 4

[Andrea Marchesini [:baku]]

https://hg.mozilla.org/integration/mozilla-inbound/rev/3428e11f9cfe

Comment 5

[Wes Kocher (:KWierso) (Not reading bugmail; email directly if needed)]

https://hg.mozilla.org/mozilla-central/rev/3428e11f9cfe

Comment 6

[Bogdan Maris, Desktop Test Engineering]

Reproduced the initial issue on older nightly build and verified that the issue is fixed using latest Aurora on Ubuntu 12.04 32bit. On Windows and Mac the pref does not exist and if I create it, nothing changes.