Reveal More Tab/Window Options
There are some hidden options for the Tabbed Browsing that will allow you to force links that open new windows to open in the current or a new tab. First, add the following code to your user.js file:
// Reveal more tab/window options:
user_pref("browser.tabs.showSingleWindowModePrefs" , true);
Restart Firefox and go to Tools > Options... (Edit > Preferences... under Linux and MacOS X), select Advanced and click on Tabbed Browsing. The following options should be visible:
Force links that open new windows to open in:
the same tab/window as the link
a new tab
The options should be self-explanatory.
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