Summary of useful posts above:
This problem arises from the way mouse button presses are handled: pressing down the right mouse button calls up the right-button-menu and then letting go of the right mouse button is interpreted as selecting whatever is underneath the mouse pointer. So if the right-button-menu is drawn under the mouse pointer, you will accidentally choose one of its options if you release the right mouse button immediately after you pressed it down.
A simple way to get rid of this "functionality" in Firefox is to install the Mouse gestures add-on, even if you don't use the gestures, this add-on will make the right-mouse-button-menu only appear after you release the right mouse button.
Summary of useful posts above:
This problem arises from the way mouse button presses are handled: pressing down the right mouse button calls up the right-button-menu and then letting go of the right mouse button is interpreted as selecting whatever is underneath the mouse pointer. So if the right-button-menu is drawn under the mouse pointer, you will accidentally choose one of its options if you release the right mouse button immediately after you pressed it down.
A simple way to get rid of this "functionality" in Firefox is to install the Mouse gestures add-on, even if you don't use the gestures, this add-on will make the right-mouse- button- menu only appear after you release the right mouse button.
Mouse gestures add-on: /addons. mozilla. org/en- US/firefox/ addon/39
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