master 3c82e96954 2/2: Add new user option display-buffer-avoid-small-windows

[Lars Ingebrigtsen]

branch: master
commit 3c82e96954450e766c63b507ed4e927d18e4cd9c
Author: Lars Ingebrigtsen <larsi@gnus.org>
Commit: Lars Ingebrigtsen <larsi@gnus.org>

    Add new user option display-buffer-avoid-small-windows
    
    * doc/lispref/windows.texi (Choosing Window Options): Document it.
    * lisp/window.el (display-buffer-avoid-small-windows): New user
    option (bug#10186).
    (get-lru-window): Use it.
---
 doc/lispref/windows.texi |  5 +++++
 etc/NEWS                 |  4 ++++
 lisp/window.el           | 23 +++++++++++++++++++----
 3 files changed, 28 insertions(+), 4 deletions(-)

diff --git a/doc/lispref/windows.texi b/doc/lispref/windows.texi
index 90551e6697..bc3857b136 100644
--- a/doc/lispref/windows.texi
+++ b/doc/lispref/windows.texi
@@ -3305,6 +3305,11 @@ window has at least that many columns.  If the value is 
@code{nil},
 that means not to split this way.
 @end defopt
 
+@defopt display-buffer-avoid-small-windows
+If non-@code{nil}, this should be a number.  Windows that have fewer
+lines than this will be avoided when choosing an existing window.
+@end defopt
+
 @defopt even-window-sizes
 This variable, if non-@code{nil}, causes @code{display-buffer} to even
 window sizes whenever it reuses an existing window, and that window is
diff --git a/etc/NEWS b/etc/NEWS
index 2314e55164..85413b0d38 100644
--- a/etc/NEWS
+++ b/etc/NEWS
@@ -605,6 +605,10 @@ specifiers can now use ':type webp'.
 
 ** Windows
 
+*** New user option 'display-buffer-avoid-small-windows'.
+If non-nil, this should be a window height.  If windows smaller than
+this will be avoided by 'display-buffer', if possible.
+
 +++
 *** New display action 'display-buffer-full-frame'.
 This action removes other windows on the frame when displaying a
diff --git a/lisp/window.el b/lisp/window.el
index 4ad2defdf9..a0c51600dc 100644
--- a/lisp/window.el
+++ b/lisp/window.el
@@ -2488,8 +2488,15 @@ and no others."
 
 (defalias 'some-window 'get-window-with-predicate)
 
+(defcustom display-buffer-avoid-small-windows nil
+  "If non-nil, windows that have fewer lines than this are avoided.
+This is used by `get-lru-window'."
+  :type '(choice nil number)
+  :version "29.1"
+  :group 'windows)
+
 (defun get-lru-window (&optional all-frames dedicated not-selected no-other)
-   "Return the least recently used window on frames specified by ALL-FRAMES.
+  "Return the least recently used window on frames specified by ALL-FRAMES.
 Return a full-width window if possible.  A minibuffer window is
 never a candidate.  A dedicated window is never a candidate
 unless DEDICATED is non-nil, so if all windows are dedicated, the
@@ -2513,15 +2520,23 @@ have special meanings:
 - A frame means consider all windows on that frame only.
 
 Any other value of ALL-FRAMES means consider all windows on the
-selected frame and no others."
-   (let (best-window best-time second-best-window second-best-time time)
-    (dolist (window (window-list-1 nil 'nomini all-frames))
+selected frame and no others.
+
+`display-buffer-avoid-small-windows' is also taken into
+consideration.  Windows smaller than this size will be avoided if
+there are larger windows available."
+  (let ((windows (window-list-1 nil 'nomini all-frames))
+        best-window best-time second-best-window second-best-time time)
+    (dolist (window windows)
       (when (and (or dedicated (not (window-dedicated-p window)))
                 (or (not not-selected) (not (eq window (selected-window))))
                  (or (not no-other)
                      (not (window-parameter window 'no-other-window))))
        (setq time (window-use-time window))
        (if (or (eq window (selected-window))
+                (and display-buffer-avoid-small-windows
+                     (< (window-height window)
+                        display-buffer-avoid-small-windows))
                (not (window-full-width-p window)))
            (when (or (not second-best-time) (< time second-best-time))
              (setq second-best-time time)