*Buffer List* column headers don't sort unless select buffer first

[Drew Adams]

emacs -q
In any buffer, for example, *scratch*, do this: `C-x C-b'.

Click any of the *Buffer List* header-line column headers. The column is not
sorted. You must first select the *Buffer List* buffer first, by, say,
clicking in its window. Then, column sorting works.

Command buffer-menu code shows that it calls `switch-to-buffer'.
However, the *Buffer List* buffer is displayed in a new window, and it
is not selected: C-x C-b, then M-: (current-buffer) shows that the
current buffer remains the original buffer (e.g. *scratch*).

The *Buffer List* buffer should be selected when you do C-x C-b, so that
column sorting works as advertised (e.g. by the help tooltips).

In GNU Emacs 21.3.50.1 (i386-mingw-nt5.1.2600)
 of 2004-07-26 on BERATUNG4
configured using `configure --with-gcc
(3.3) --cflags -I../../jpeg-6b-1/include -I../../libpng-1.2.4-1/include -I..
/../tiff-3.5.7/include -I../../xpm-nox-4.2.0/include -I../../zlib-1.1.4-1/in
clude'