479429 - Attempting to upload an unreadable file produces no error, but uploads a 0 byte file

Status: NEW

(Firefox :: File Handling, defect)

Description

[Chris Jones]

User-Agent:       Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.9.0.6) Gecko/2009020518 Ubuntu/9.04 (jaunty) Firefox/3.0.6
Build Identifier: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.9.0.6) Gecko/2009020518 Ubuntu/9.04 (jaunty) Firefox/3.0.6

If one is trying to upload a file to a web site and one is unable to read that file (e.g. one does not have permissions to do so), Firefox will not display an error message, it will simply upload the file as 0 bytes, which may confuse the web application.

Reproducible: Always

Steps to Reproduce:
1. Visit a site that accepts file uploads
2. Upload a file your user does not have permissions to read
3.
Actual Results:  
Silent fail

Expected Results:  
Noisy fail

Some have argued that this is a High/Critical bug since users could be silently uploading empty data over real data, and thus losing it.

Comment 1

[dmck]

I have noticed this issue as well.

Running Firefox 3.0.6 on Ubuntu Linux, the file upload browser lets me see
files that I have read permission to.

But if the file does not have world read permission then the upload silently
fails and sends a zero length file

Comment 3

[thierry.vignaud]

As for firefox 15 beta 6, firefox just silently fails.
Eg: trying to upload the unreadable file (eg: echo >test.txt;chmod 000 test.txt) result in nothing happening when cliking on submit (tested on bugzilla, webmail, ...)

I've reported a similar same issue in chromium and it was fixed : https://code.google.com/p/chromium/issues/detail?id=30850&can=1&q=vignaud&colspec=ID%20Pri%20Mstone%20ReleaseBlock%20OS%20Area%20Feature%20Status%20Owner%20Summary

Comment 4

[[:Aleksej]]

(In reply to thierry.vignaud from comment #3)
> As for firefox 15 beta 6, firefox just silently fails.
> Eg: trying to upload the unreadable file (eg: echo >test.txt;chmod 000
> test.txt) result in nothing happening when cliking on submit (tested on
> bugzilla, webmail, ...)

I think I‘ve seen the same about when I marked this NEW.  Morph or WORKSFORME?

Comment 5

[thierry.vignaud]

What about adding check wiht stat() and warn about unreadable files?