>     emacs -Q -nw
>     (set-scroll-bar-mode 'right) C-j
>     C-x 3
>
>     Here, an error "Wrong type argument: number-or-marker-p, nil" is issued.
>
> When enabling debug on error, it appears as though the problem is in the
> function `window--min-size-1'.

Sorry, I can't check that here.  Are you sure the bug does not happen
with scrollbars on the left?

> In GNU Emacs 24.3.50.2 (x86_64-apple-darwin13.0.0, NS apple-appkit-1265.00)
>  of 2014-02-16 on macpro.lan
> Repository revision: 116451
> jan.h.d@swipnet.se-20140216095141-cop794qd0bf30tmt

I have made some changes in this area recently.  Maybe upgrading helps.

> window--min-size-1: Wrong type argument: number-or-marker-p, nil

Could you get a more maningful backtrace here?  Can you step through
this with the debugger?

martin