I run Linux, and am used to selecting text with the mouse to copy and pressing Shift+Insert to paste. (This uses an alternate clipboard known as the "Primary Selection".)
This seems to work in every application besides Firefox. Firefox uses a different clipboard, where Ctrl+C copies and Ctrl+V pastes. Is there a keystroke or configuration change I can do to make Firefox paste from the Unix "primary selection" clipboard — the one it pastes from when I click the middle mouse button?
Note: I'm looking for a keyboard shortcut, not a mouse action.