New variable 'expose-hidden-buffer' (Bug#75828)

* src/frame.c (make_frame): Handle 'expose-hidden-buffer'.
(expose-hidden-buffer): New variable to handle hidden buffers.
* src/buffer.c (Fother_buffer): Mention that it does not return
a hidden buffer.
* lisp/frame.el (make-frame): In doc-string describe handling
of hidden buffers.
* doc/lispref/frames.texi (Creating Frames): Explain handling
of hidden buffers in description of 'make-frame'.

1 files changed, 7 insertions, 0 deletions

diff --git a/doc/lispref/frames.texi b/doc/lispref/frames.texi
index c71b977550e..52af34389c5 100644
--- a/doc/lispref/frames.texi
+++ b/doc/lispref/frames.texi
@@ -162,6 +162,13 @@ This function itself does not make the new frame the selected frame.
 @xref{Input Focus}.  The previously selected frame remains selected.
 On graphical terminals, however, the window system may select the
 new frame for its own reasons.
+
+By default this function does not display the current buffer in the new
+frame if the buffer is hidden, that is, if its name starts with a space.
+In this case it will show another buffer - one that could be returned by
+the function @code{other-buffer} (@pxref{Buffer List}) - instead.
+However, if the variable @code{expose-hidden-buffer} is non-@code{nil},
+this function will display the current buffer even if it is hidden.
 @end deffn
 
 @defvar before-make-frame-hook