From MozillaZine Knowledge Base
When restarting Firefox due to an upgrade, installed or updated extensions, or installed or updated themes, every browser window will be closed. This preference determines whether or not a warning dialog appears before this happens.
Possible values and their effects
Display a dialog before restarting the browser, warning that all windows will be closed. (Default)
Do not require confirmation from the user when restarting.
A checkbox labeled “Do not ask next time” appears on the confirmation dialog; when checked, this preference is toggled to false.
First checked in
2008-02-23 by Reed Loden (patch by Dão Gottwald)
Has an effect in
- Firefox (nightly builds since 2008-02-23)