core: Factor out spacemacs-buffer creation

Factor out the code related to creating the spacemacs buffer, so that it
can be recreated easily if it gets deleted.

core/core-spacemacs-buffer.el

@@ -549,4 +549,40 @@ HPADDING is the horizontal spacing betwee the content line and the frame border.
     (beginning-of-line)
     (widget-forward 1)))
 
+(defun spacemacs-buffer/goto-buffer ()
+  "Create the special buffer for `spacemacs-mode' if it doesn't
+already exist, and switch to it."
+  (interactive)
+  (unless (buffer-live-p (get-buffer spacemacs-buffer-name))
+    (with-current-buffer (get-buffer-create spacemacs-buffer-name)
+      (save-excursion
+        (spacemacs-buffer/set-mode-line "")
+        ;; needed in case the buffer was deleted and we are recreating it
+        (setq spacemacs-buffer--note-widgets nil)
+        (spacemacs-buffer/insert-banner-and-buttons)
+        ;; non-nil if emacs is loaded
+        (if after-init-time
+            (progn
+              (when dotspacemacs-startup-lists
+                (spacemacs-buffer/insert-startupify-lists))
+              (spacemacs-buffer/set-mode-line spacemacs--default-mode-line)
+              (force-mode-line-update)
+              (spacemacs-buffer-mode))
+          (add-hook 'emacs-startup-hook
+                    (lambda ()
+                      (with-current-buffer (get-buffer-create spacemacs-buffer-name)
+                        (when dotspacemacs-startup-lists
+                          (spacemacs-buffer/insert-startupify-lists))
+                        (if configuration-layer-error-count
+                            (spacemacs-buffer/set-mode-line
+                             (format (concat "%s error(s) at startup! "
+                                             "Spacemacs may not be able to operate properly.")
+                                     configuration-layer-error-count))
+                          (spacemacs-buffer/set-mode-line spacemacs--default-mode-line))
+                        (force-mode-line-update)
+                        (spacemacs-buffer-mode)
+                        (spacemacs-buffer/goto-link-line))))))))
+  (spacemacs-buffer/goto-link-line)
+  (switch-to-buffer spacemacs-buffer-name))
+
 (provide 'core-spacemacs-buffer)

core/core-spacemacs.el

@@ -67,8 +67,7 @@
   (add-to-list 'evil-motion-state-modes 'spacemacs-mode))
 
 (defun spacemacs/init ()
-  "Create the special buffer for `spacemacs-mode' and perform startup
-initialization."
+  "Perform startup initialization."
   ;; explicitly set the prefered coding systems to avoid annoying prompt
   ;; from emacs (especially on Microsoft Windows)
   (prefer-coding-system 'utf-8)
@@ -79,11 +78,8 @@ initialization."
   (dotspacemacs|call-func dotspacemacs/init "Calling dotfile init...")
   (dotspacemacs|call-func dotspacemacs/user-init "Calling dotfile user init...")
   ;; spacemacs init
-  (switch-to-buffer (get-buffer-create spacemacs-buffer-name))
+  (spacemacs-buffer/goto-buffer)
   (setq initial-buffer-choice (lambda () (get-buffer spacemacs-buffer-name)))
-  (spacemacs-buffer/set-mode-line "")
-  ;; no welcome buffer
-  (setq inhibit-startup-screen t)
   ;; silence ad-handle-definition about advised functions getting redefined
   (setq ad-redefinition-action 'accept)
   ;; removes the GUI elements
@@ -121,8 +117,6 @@ initialization."
       (spacemacs/set-default-font dotspacemacs-default-font)
     (spacemacs-buffer/warning "Cannot find font \"%s\"!"
                               (car dotspacemacs-default-font)))
-  ;; banner
-  (spacemacs-buffer/insert-banner-and-buttons)
   ;; mandatory dependencies
   ;; dash is required to prevent a package.el bug with f on 24.3.1
   (spacemacs/load-or-install-protected-package 'dash t)
@@ -153,9 +147,7 @@ initialization."
   ;; check for new version
   (if dotspacemacs-mode-line-unicode-symbols
       (setq-default spacemacs-version-check-lighter "[⇪]"))
-  (spacemacs/set-new-version-lighter-mode-line-faces)
-  (add-hook 'emacs-startup-hook 'spacemacs-buffer/goto-link-line)
-  (spacemacs-mode))
+  (spacemacs/set-new-version-lighter-mode-line-faces))
 
 (defun spacemacs/maybe-install-dotfile ()
   "Install the dotfile if it does not exist."
@@ -199,16 +191,6 @@ initialization."
         (format "\n[%s packages loaded in %.3fs]\n"
                 (configuration-layer/configured-packages-count)
                 elapsed)))
-     ;; Display useful lists of items
-     (when dotspacemacs-startup-lists
-       (spacemacs-buffer/insert-startupify-lists))
-     (if configuration-layer-error-count
-         (spacemacs-buffer/set-mode-line
-          (format (concat "%s error(s) at startup! "
-                          "Spacemacs may not be able to operate properly.")
-                  configuration-layer-error-count))
-       (spacemacs-buffer/set-mode-line spacemacs--default-mode-line))
-     (force-mode-line-update)
      (spacemacs/check-for-new-version spacemacs-version-check-interval))))
 
 (defun spacemacs/describe-system-info ()

layers/+distribution/spacemacs-base/funcs.el

@@ -405,10 +405,8 @@ argument takes the kindows rotate backwards."
   (delete-other-windows)
   (split-window-right))
 
-(defun spacemacs/home ()
-  "Go to home Spacemacs buffer"
-  (interactive)
-  (switch-to-buffer "*spacemacs*"))
+(defalias 'spacemacs/home 'spacemacs-buffer/goto-buffer
+  "Go to home Spacemacs buffer")
 
 (defun spacemacs/insert-line-above-no-indent (count)
   (interactive "p")