Improve support for desktop restoration in daemon mode

* lisp/server.el (server-after-make-frame-hook): New hook.
(server-execute): Call it after creating a new frame or before
switching to a buffer shown in a client frame.  (Bug#30421)

* doc/emacs/misc.texi (Saving Emacs Sessions): Adjust advice for
restoring desktop in daemon mode to the new hook.
* doc/lispref/frames.texi (Creating Frames, Standard Hooks):
Document server-after-make-frame-hook.

* etc/NEWS: Mention server-after-make-frame-hook.

doc/emacs/misc.texi

@@ -2529,7 +2529,7 @@ e.g., the daemon cannot use GUI features, so parameters such as frame
 position, size, and decorations cannot be restored.  For that reason,
 you may wish to delay restoring the desktop in daemon mode until the
 first client connects, by calling @code{desktop-read} in a hook
-function that you add to @code{after-make-frame-functions}
+function that you add to @code{server-after-make-frame-hook}
 (@pxref{Creating Frames,,, elisp, The Emacs Lisp Reference Manual}).
 
 @node Recursive Edit

doc/lispref/frames.texi

@@ -181,6 +181,12 @@ the value of that parameter in the created frame to its value in the
 selected frame.
 @end defvar
 
+@defopt server-after-make-frame-hook
+A normal hook run when the Emacs server creates a client frame.  When
+this hook is called, the created frame is the selected one.
+@xref{Emacs Server,,, emacs, The GNU Emacs Manual}.
+@end defopt
+
 
 @node Multiple Terminals
 @section Multiple Terminals

doc/lispref/hooks.texi

@@ -66,6 +66,7 @@ not exactly a hook, but does a similar job.
 
 @item after-make-frame-functions
 @itemx before-make-frame-hook
+@itemx server-after-make-frame-hook
 @xref{Creating Frames}.
 
 @c Not general enough?

etc/NEWS

@@ -83,6 +83,15 @@ Customize the option 'mode-line-default-help-echo' to restore the old
 behavior where the tooltip text is also shown when the corresponding
 action does not apply.
 
++++
+** New hook 'server-after-make-frame-hook'.
+This hook is a convenient place to perform initializations in daemon
+mode which require GUI features to be available.  One example is
+restoration of the previous session using the desktop.el package: put
+the call to 'desktop-read' in this hook, if you want the GUI settings
+to be restored, or if desktop.el needs to interact with you during
+restoration of the session.
+
 +++
 ** New function 'logcount' calculates an integer's Hamming weight.
 

lisp/server.el

@@ -188,6 +188,13 @@ space (this means characters from ! to ~; or from code 33 to
   :group 'server
   :type 'hook)
 
+(defcustom server-after-make-frame-hook nil
+  "Hook run when the Emacs server creates a client frame.
+The created frame is selected when the hook is called."
+  :group 'server
+  :type 'hook
+  :version "27.1")
+
 (defcustom server-done-hook nil
   "Hook run when done editing a buffer for the Emacs server."
   :group 'server
@@ -1336,9 +1343,11 @@ The following commands are accepted by the client:
            ((or isearch-mode (minibufferp))
             nil)
            ((and frame (null buffers))
+            (run-hooks 'server-after-make-frame-hook)
             (message "%s" (substitute-command-keys
                            "When done with this frame, type \\[delete-frame]")))
            ((not (null buffers))
+            (run-hooks 'server-after-make-frame-hook)
             (server-switch-buffer (car buffers) nil (cdr (car files)))
             (run-hooks 'server-switch-hook)
             (unless nowait