Middle mouse button in Firefox performs random actions

[jon chambers]

Clicking the middle mouse button in Firefox (both 3 and 3.5) has inconsistent results. The correct behaviour is to open a link in a new tab.

But middle clicking in empty spaces on webpages produces random results. Sometimes a new page opens with a random word from the previous page as the url. Sometimes a previous page is loaded. Sometimes an apparently random page is loaded. Sometimes the error "the url is not valid and cannot be loaded" is produced.

This can be fixed by setting middlemouse.contentLoadURL to FALSE as default.

[jon chambers (jon-chambers3001)]

This is NOT a duplicate of bug #386017 (as it was previously tagged) as it is not at all specific to touchpads (occurs using any 3-button mouse). It is also specifically a firefox issue (it has affected all versions of Firefox on all varieties of Linux I have used). I am not the only one: http://ubuntuforums.org/showthread.php?t=260707

The suggested fix solves the issue and doesn't appear to affect any functions - it would be trivial to make this change default.

[Przemek K. (azrael)]

I think the behaviour that you are experiencing is just by design of Firefox. Middle-clicking in empty space makes Firefox load an URL from the selection clipboard. If the clipboard contains some random words/junk, then you are getting these errors that you've mentioned.

[jon chambers (jon-chambers3001)]

I realised after some research that this is probably the case. However on windows middle click simply starts universal scroll, which seems more generally useful.
Crucially though a default behavoir that in many cases produces a random/garbage result doesn't seem at all user-friendly.
Perhaps I should open a bug in firefox if there isn't one already?