attached.
 >>   > 1. If there is a window displaying BUFFER, switch to that window
 >>   > 2. If there is a window that is an indirect buffer of BUFFER or that
 >>   >     shares the same base buffer with BUFFER, switch to that window
 >>
 >> I included the facility that if there is a window whose buffer is the
 >> base buffer of BUFFER use that window.  See the attached diff which I
 >> did not test very thoroughly.
 >
 > Thanks!
 > It seems to work, although somewhat different than I described.
 >
 > With your diff, in case (2), if BUFFER is what is passed to
 > `pop-to-buffer' and BUFFER2 is indirectly related buffer displayed in a
 > visible window, then BUFFER2 is replaced with BUFFER. I expected that
 > BUFFER2's window will be selected; nothing more.

Hmmm...  This is not really what 'display-buffer' is supposed to do.  I
have to disguise the fact that we wanted to display BUFFER.  I attach a
new patch.

martin