From aec896c939791ffa09993d7a6a8b2f4f8bcf42f1 Mon Sep 17 00:00:00 2001
From: Daniel Borchmann <daniel@algebra20.de>
Date: Sat, 11 Feb 2023 19:33:19 +0100
Subject: [PATCH] Always display shell buffers at bottom of frame in dedicated
 window

Inspired by https://www.masteringemacs.org/article/demystifying-emacs-window-manager.
---
 site-lisp/db-eshell.el | 13 ++++++-------
 site-lisp/db-utils.el  | 10 +++++-----
 2 files changed, 11 insertions(+), 12 deletions(-)

diff --git a/site-lisp/db-eshell.el b/site-lisp/db-eshell.el
index 58eeba5..e068598 100644
--- a/site-lisp/db-eshell.el
+++ b/site-lisp/db-eshell.el
@@ -28,25 +28,24 @@
   ;; idea to split the current window is from
   ;; http://howardism.org/Technical/Emacs/eshell-fun.html
   (interactive "P")
-  (if (string= "eshell-mode" major-mode)
+  (if (derived-mode-p 'eshell-mode)
       ;; bury buffer; reopen with current working directory if arg is given
       (progn
         (bury-buffer)
-        (delete-window)
         (and arg (db/run-or-hide-eshell arg)))
     (if-let ((eshell-window (db/find-window-by-buffer-mode 'eshell-mode)))
         (select-window eshell-window)
       ;; open eshell
-      (let ((current-dir (expand-file-name default-directory))
-            (height      (/ (window-total-height) 3)))
-        (split-window-vertically (- height))
-        (other-window 1)
+      (let* ((current-dir (expand-file-name default-directory))
+             (height      (/ (frame-text-lines) 3)))
+        (select-window (split-window (frame-root-window) (- height) 'below))
         (eshell 1)
         (when arg
           (end-of-line)
           (eshell-kill-input)
           (insert (format "cd '%s'" current-dir))
-          (eshell-send-input))))))
+          (eshell-send-input))))
+    (set-window-dedicated-p (selected-window) t)))
 
 (defun eshell-clear-buffer ()
   "Clear terminal."
diff --git a/site-lisp/db-utils.el b/site-lisp/db-utils.el
index d383f08..4b0cc86 100644
--- a/site-lisp/db-utils.el
+++ b/site-lisp/db-utils.el
@@ -75,15 +75,15 @@ If already in `*ansi-term*' buffer, bury it."
               (if-let ((shell-window (db/find-window-by-buffer-mode 'shell-mode)))
                   (select-window shell-window)
                 ;; open shell in buffer with height of ⅓ of current window
-                (let ((height (/ (window-total-height) 3)))
-                  (shell)
-                  (enlarge-window (- height (window-total-height)))))))
+                (let ((height (/ (frame-text-lines) 3)))
+                  (select-window (split-window (frame-root-window) (- height) 'below))
+                  (shell)))
+              (set-window-dedicated-p (selected-window) t)))
     (if (not arg)
         ;; toggle shell window
         (if (not (derived-mode-p 'shell-mode))
             (change-to-shell)
-          (bury-buffer)
-          (delete-window))
+          (bury-buffer))
 
       ;; unconditionally go to shell, and also change to cwd
       (let ((current-dir (expand-file-name default-directory)))