general.useragent.override in firefox spontaneously switches to quicktime 7

[Robert Persson]

Binary package hint: firefox-3.5

On two separate occasions I have found that Gmail has forced a switch to basic html mode. On both occasions it has turned out that the reason has been that the value of general.useragent.override has switched to Quicktime 7.6.2 instead of Firefox. Obviously this should not happen. I have no idea what triggers it.

ProblemType: Bug
Architecture: amd64
Date: Wed Feb 10 20:42:58 2010
DistroRelease: Ubuntu 9.10
InstallationMedia: Kubuntu 9.10 "Karmic Koala" - Release amd64 (20091027)
Package: firefox 3.5.7+nobinonly-0ubuntu0.9.10.1
PackageArchitecture: all
ProcEnviron:
 LANGUAGE=
 PATH=(custom, no user)
 LANG=en_US.UTF-8
 SHELL=/bin/bash
SourcePackage: firefox-3.5
Uname: Linux 2.6.31.6-rt19 x86_64

[Rodd Snook (snookums)]

I can confirm that I've just had this happen with Firefox 3.6.3. The user agent has been changed to "QuickTime/7.6.4".

This is running 10.04 with firefox 3.6.3+nobinonly-0ubuntu4 installed.

I noticed this problem after an unexpected exit of Firefox (i.e a crash) on a media-heavy site (http://wellthatsadorable.com/). I suspect that gecko-mediaplayer sets this value in order to convince a QuickTime streaming server that it can handle the media, then resets the value after the media is loaded. In the case of a crash the override value is left in place.

The reason for suspecting gecko-mediaplayer is that about:plugins shows:

QuickTime Plug-in 7.6.4
    File: gecko-mediaplayer-qt.so
    Version:
    Gecko Media Player 0.9.9.2

QuickTime Plug-in 7.6.6
    File: libtotem-narrowspace-plugin.so
    Version:
    The Totem 2.30.2 plugin handles video and audio streams.

The 7.6.4 version in the useragent string matches that reported by the gecko-mediaplayer plugin.

[papukaija (papukaija)]

Changed to the general package since this bug is confirmed in lucid.

[Chris Coulson (chrisccoulson)]

Not a firefox issue. gecko-mediaplayer changes this value and is meant to change it back again when firefox exits

[Ben Klaasen (ben-fluidlogic)]

For folks looking to restore the correct useragent string:

   * browse to about:config
   * accept the warning message
   * search for "general.useragent.override" in the Filter: box
   * right-click on the matching line in the filtered results and click "Reset".
   * Finally, browse to http://www.iwebtool.com/browser_details to confirm the correct value has been restored.