bug#23131: switch-to-buffer-other-frame problem

[jan <rtm443x@googlemail.com>]

Running emacs 24.5.1 on windows.

Hi all,
switch-to-buffer-other-frame works but should prompt for the name of
the buffer to switch to. Per the help on that function "If called
interactively, prompt for the buffer name using the minibuffer". Well
it does but then refuses to recognise my buffer by name.

---------

e.g Start emacs, then drag a file (say sample.txt) onto it. File opens fine.

Type C-x 5 b

- minibuffer shows
"Switch to buffer in other frame (default *GNU Emacs*): "

I type "sam" [tab key for completion]

- minibuffer says
"Switch to buffer in other frame (default *GNU Emacs*): sam[No Match]"

odd. If I remove the "sam" I just typed then type '?' to show the
buffer list, it opens a 2nd buffer at the bottom and shows

Possible completions are:
*GNU Emacs*
*Messages*
*scratch*

which does not show sample.txt, which is definitly there as I can see
it open in the buffer at the top.

As a workaround, I enter a nonexistent buffer name, the 2nd frame
opens, blank, I then do
C-x b
sam            <- I type this in
[tab for completion]
sample.txt  <- emacs autocompletes this
RET  <- to accept

and sample.txt is now shown in the other frame as I want. But this is
a workaround.

----------------

Having raised this with Eli, he says this is expected behaviour: "Yes,
it's a feature: Emacs doesn't offer you a buffer that is already
displayed in an existing window.  This was introduced in Emacs 24."

Well, a) this is not documented (see below) and b) I can't see any
rationale for this behaviour. Hiding this option does not assist the
user in any way I can see.

Also, the behaviour is apparently broken if the current buffer/window is split:

a. open sample.txt
b. C-x 2   -- split window in 2, top and bottom
c. C-x 5 b  -- try to get 2nd frame
d. sample.txt   -- type in full filename in minibuffer
e. 2nd frame does *not* appear, cursor jumps to top of split window,
even if was originally in bottom.

can reproduce?

jan


I said this behaviour isn't documented that I can see. Here's the full
docs for this function. It says nothing about hiding the current
buffer name:

-------
switch-to-buffer-other-frame is an interactive compiled Lisp function
in `window.el'.

It is bound to C-x 5 b.

(switch-to-buffer-other-frame BUFFER-OR-NAME &optional NORECORD)

Switch to buffer BUFFER-OR-NAME in another frame.
BUFFER-OR-NAME may be a buffer, a string (a buffer name), or
nil.  Return the buffer switched to.

If called interactively, prompt for the buffer name using the
minibuffer.  The variable `confirm-nonexistent-file-or-buffer'
determines whether to request confirmation before creating a new
buffer.

If BUFFER-OR-NAME is a string and does not identify an existing
buffer, create a new buffer with that name.  If BUFFER-OR-NAME is
nil, switch to the buffer returned by `other-buffer'.

Optional second arg NORECORD non-nil means do not put this
buffer at the front of the list of recently selected ones.

This uses the function `display-buffer' as a subroutine; see its
documentation for additional customization information.
-------