Improve 'display-buffer' 'temp-buffer-resize-mode' cohabitation (Bug#51062)

* doc/lispref/display.texi (Temporary Displays): Explain how
to override the effect of 'temp-buffer-resize-mode' with a
suitable 'display-buffer' action alist entry.
* doc/lispref/windows.texi (Buffer Display Action Alists):
Mention that an 'inhibit-switch-frame' entry might not work
with every WM.  Describe the 'window-size' entry.  Describe
how automatic window resizing can be overridden.
* lisp/help.el (resize-temp-buffer-window-inhibit): New variable.
(resize-temp-buffer-window): Handle case where user overrides
automatic resizing.
* lisp/window.el (temp-buffer-window-show): Bind
'resize-temp-buffer-window-inhibit' to nil around
'display-buffer'.  Do not raise frame automatically to avoid
defeating 'inhibit-switch-frame'.
(window--display-buffer): Set 'resize-temp-buffer-window-inhibit'
to t when the action alist contains a 'window-height',
'window-width' or 'window-size' entry.  Use
'modify-frame-parameters' instead of 'set-frame-height' and
'set-frame-width' to avoid that the latter step on each others
toes.
(display-buffer): Fix 'inhibit-switch-frame' part in and add
'window-size' part to doc-string.

2 files changed, 73 insertions, 38 deletions

diff --git a/lisp/help.el b/lisp/help.el
index eaca33795ae..fa4eaee417d 100644
--- a/lisp/help.el
+++ b/lisp/help.el
@@ -1596,10 +1596,16 @@ and some others."
       (add-hook 'temp-buffer-show-hook 'resize-temp-buffer-window 'append)
     (remove-hook 'temp-buffer-show-hook 'resize-temp-buffer-window)))
 
+(defvar resize-temp-buffer-window-inhibit nil
+  "Non-nil means `resize-temp-buffer-window' should not resize.")
+
 (defun resize-temp-buffer-window (&optional window)
   "Resize WINDOW to fit its contents.
 WINDOW must be a live window and defaults to the selected one.
-Do not resize if WINDOW was not created by `display-buffer'.
+Do not resize if WINDOW was not created by `display-buffer'.  Do
+not resize either if a `window-height', `window-width' or
+`window-size' entry in `display-buffer-alist' prescribes some
+alternative resizing for WINDOW's buffer.
 
 If WINDOW is part of a vertical combination, restrain its new
 size by `temp-buffer-max-height' and do not resize if its minimum
@@ -1614,27 +1620,33 @@ provided `fit-frame-to-buffer' is non-nil.
 This function may call `preserve-window-size' to preserve the
 size of WINDOW."
   (setq window (window-normalize-window window t))
-  (let ((height (if (functionp temp-buffer-max-height)
+  (let* ((buffer (window-buffer window))
+         (height (if (functionp temp-buffer-max-height)
+                     (with-selected-window window
+                       (funcall temp-buffer-max-height buffer))
+                   temp-buffer-max-height))
+         (width (if (functionp temp-buffer-max-width)
                     (with-selected-window window
-                      (funcall temp-buffer-max-height (window-buffer)))
-                  temp-buffer-max-height))
-        (width (if (functionp temp-buffer-max-width)
-                   (with-selected-window window
-                     (funcall temp-buffer-max-width (window-buffer)))
-                 temp-buffer-max-width))
-        (quit-cadr (cadr (window-parameter window 'quit-restore))))
-    ;; Resize WINDOW iff it was made by `display-buffer'.
+                      (funcall temp-buffer-max-width buffer))
+                  temp-buffer-max-width))
+         (quit-cadr (cadr (window-parameter window 'quit-restore))))
+    ;; Resize WINDOW only if it was made by `display-buffer'.
     (when (or (and (eq quit-cadr 'window)
                    (or (and (window-combined-p window)
                             (not (eq fit-window-to-buffer-horizontally
                                      'only))
-                            (pos-visible-in-window-p (point-min) window))
+                            (pos-visible-in-window-p
+                             (with-current-buffer buffer (point-min))
+                             window)
+                            (not resize-temp-buffer-window-inhibit))
                        (and (window-combined-p window t)
-                            fit-window-to-buffer-horizontally)))
+                            fit-window-to-buffer-horizontally
+                            (not resize-temp-buffer-window-inhibit))))
               (and (eq quit-cadr 'frame)
                    fit-frame-to-buffer
-                   (eq window (frame-root-window window))))
-        (fit-window-to-buffer window height nil width nil t))))
+                   (eq window (frame-root-window window))
+                   (not resize-temp-buffer-window-inhibit)))
+      (fit-window-to-buffer window height nil width nil t))))
 
 ;;; Help windows.
 (defcustom help-window-select nil
diff --git a/lisp/window.el b/lisp/window.el
index 971264b6344..1a5f2d40067 100644
--- a/lisp/window.el
+++ b/lisp/window.el
@@ -108,11 +108,14 @@ Return the buffer."
       ;; Return the buffer.
       buffer)))
 
+;; Defined in help.el.
+(defvar resize-temp-buffer-window-inhibit)
+
 (defun temp-buffer-window-show (buffer &optional action)
   "Show temporary buffer BUFFER in a window.
 Return the window showing BUFFER.  Pass ACTION as action argument
 to `display-buffer'."
-  (let (window frame)
+  (let (resize-temp-buffer-window-inhibit window)
     (with-current-buffer buffer
       (set-buffer-modified-p nil)
       (setq buffer-read-only t)
@@ -130,9 +133,9 @@ to `display-buffer'."
                        t
                      window-combination-limit)))
               (setq window (display-buffer buffer action)))
-        (setq frame (window-frame window))
-        (unless (eq frame (selected-frame))
-          (raise-frame frame))
+        ;; We used to raise the window's frame here.  Do not do that
+        ;; since it would override an `inhibit-switch-frame' entry
+        ;; specified for the action alist used by `display-buffer'.
         (setq minibuffer-scroll-window window)
         (set-window-hscroll window 0)
         (with-selected-window window
@@ -7246,11 +7249,14 @@ Return WINDOW if BUFFER and WINDOW are live."
             (inhibit-modification-hooks t))
         (funcall (cdr (assq 'body-function alist)) window)))
 
-    (let ((quit-restore (window-parameter window 'quit-restore))
-          (height (cdr (assq 'window-height alist)))
-          (width (cdr (assq 'window-width alist)))
-          (size (cdr (assq 'window-size alist)))
-          (preserve-size (cdr (assq 'preserve-size alist))))
+    (let* ((quit-restore (window-parameter window 'quit-restore))
+           (window-height (assq 'window-height alist))
+           (height (cdr window-height))
+           (window-width (assq 'window-width alist))
+           (width (cdr window-width))
+           (window-size (assq 'window-size alist))
+           (size (cdr window-size))
+           (preserve-size (cdr (assq 'preserve-size alist))))
       (cond
        ((or (eq type 'frame)
             (and (eq (car quit-restore) 'same)
@@ -7267,14 +7273,18 @@ Return WINDOW if BUFFER and WINDOW are live."
                 (height (cdr size))
                 (frame (window-frame window)))
             (when (and (numberp width) (numberp height))
-              (set-frame-height
-               frame (+ (frame-height frame)
-                        (- height (window-total-height window))))
-              (set-frame-width
-               frame (+ (frame-width frame)
-                        (- width (window-total-width window)))))))
+              ;; Modifying the parameters of a newly created frame might
+              ;; not work everywhere, but then `temp-buffer-resize-mode'
+              ;; will certainly fail in a similar fashion.
+              (modify-frame-parameters
+               frame `((height . ,(+ (frame-height frame)
+                                     (- height (window-total-height window))))
+                       (width . ,(+ (frame-width frame)
+                                    (- width (window-total-width window))))))))
+          (setq resize-temp-buffer-window-inhibit t))
          ((functionp size)
-          (ignore-errors (funcall size window)))))
+          (ignore-errors (funcall size window))
+          (setq resize-temp-buffer-window-inhibit t))))
        ((or (eq type 'window)
             (and (eq (car quit-restore) 'same)
                  (eq (nth 1 quit-restore) 'window)))
@@ -7294,9 +7304,11 @@ Return WINDOW if BUFFER and WINDOW are live."
                  (delta (- new-height (window-total-height window))))
             (when (and (window--resizable-p window delta nil 'safe)
                        (window-combined-p window))
-              (window-resize window delta nil 'safe))))
+              (window-resize window delta nil 'safe)))
+          (setq resize-temp-buffer-window-inhibit 'vertical))
          ((functionp height)
-          (ignore-errors (funcall height window))))
+          (ignore-errors (funcall height window))
+          (setq resize-temp-buffer-window-inhibit 'vertical)))
         ;; Adjust width of window if asked for.
         (cond
          ((not width))
@@ -7310,9 +7322,11 @@ Return WINDOW if BUFFER and WINDOW are live."
                  (delta (- new-width (window-total-width window))))
             (when (and (window--resizable-p window delta t 'safe)
                        (window-combined-p window t))
-              (window-resize window delta t 'safe))))
+              (window-resize window delta t 'safe)))
+          (setq resize-temp-buffer-window-inhibit 'horizontal))
          ((functionp width)
-          (ignore-errors (funcall width window))))
+          (ignore-errors (funcall width window))
+          (setq resize-temp-buffer-window-inhibit 'horizontal)))
         ;; Preserve window size if asked for.
         (when (consp preserve-size)
           (window-preserve-size window t (car preserve-size))
@@ -7557,9 +7571,11 @@ perform.
 Action alist entries are:
  `inhibit-same-window' -- A non-nil value prevents the same
     window from being used for display.
- `inhibit-switch-frame' -- A non-nil value prevents any frame
-    used for showing the buffer from being raised or selected.
- `reusable-frames' -- The value specifies the set of frames to
+`inhibit-switch-frame' -- A non-nil value prevents any frame used
+    for showing the buffer from being raised or selected.  Note
+    that a window manager may still raise a new frame and give it
+    focus, effectively overriding the value specified here.
+`reusable-frames' -- The value specifies the set of frames to
     search for a window that already displays the buffer.
     Possible values are nil (the selected frame), t (any live
     frame), visible (any visible frame), 0 (any visible or
@@ -7582,7 +7598,14 @@ Action alist entries are:
     window) or a function to be called with one argument - the
     chosen window.  The function is supposed to adjust the width
     of the window; its return value is ignored.
- `preserve-size' -- The value should be either (t . nil) to
+ `window-size' -- This entry is only useful for windows appearing
+    alone on their frame and specifies the desired size of that
+    window either as a cons of integers (the total width and
+    height of the window on that frame), or a function to be
+    called with one argument - the chosen window.  The function
+    is supposed to adjust the size of the frame; its return value
+    is ignored.
+`preserve-size' -- The value should be either (t . nil) to
     preserve the width of the chosen window, (nil . t) to
     preserve its height or (t . t) to preserve its height and
     width in future changes of the window configuration.