write-region-internal breakage (in conjunction with indirect buffers)

When you do (write-region start end file APPEND VISIT) on an *indirect* buffer then write-region-internal gives an error that you cannot visit in an indirect buffer even if VISIT is nil or some other symbol (like 'nomessage). It seems that write-region-internal doesn't check what VISIT actually is and simply gives an error in all cases. I tested this on 21.4 (don't have the cvs sources handy). Also, is it a big problem to add the 'clone (third) argument to make-indirect-buffer, like in FSF version of emacs (so that both the major and the minor modes would be inherited)? thanks --michael