[rmail-mbox-branch]: summary now showing up...

[Alfred M. Szmidt]

If one splits a window, switches to some random buffer that isn't your
RMAIL summary buffer.  And tries to do rmail-summary in the other,
then the first window won't switch to the rmail rmail summary buffer
for your mailbox..

That is if we do:

1) split window
2) switch to  non-RMAIL summary buffer in window 1
3) switch to RMAIL buffer (not summary!) in window 2
4) Call rmail-summary

then rmail won't show the summary buffer in window 1.

It works if you only have one window though.