Ensure workspace in insertion order

Closes #2488
Fixes #2487

modules/ui/workspaces/autoload/workspaces.el

@@ -68,13 +68,14 @@ error if NAME doesn't exist."
   "Return a list of workspace structs (satisifes `+workspace-p')."
   ;; We don't use `hash-table-values' because it doesn't ensure order in older
   ;; versions of Emacs
-  (cdr (cl-loop for persp being the hash-values of *persp-hash*
-                collect persp)))
+  (cl-loop for name in persp-names-cache
+           if (gethash name *persp-hash*)
+           collect it))
 
 ;;;###autoload
 (defun +workspace-list-names ()
   "Return the list of names of open workspaces."
-  (mapcar #'safe-persp-name (+workspace-list)))
+  persp-names-cache)
 
 ;;;###autoload
 (defun +workspace-buffer-list (&optional persp)

modules/ui/workspaces/config.el

@@ -76,10 +76,13 @@ stored in `persp-save-dir'.")
       "Ensure a main workspace exists."
       (when persp-mode
         (let (persp-before-switch-functions)
-          ;; The default perspective persp-mode creates (`persp-nil-name') is
-          ;; special and doesn't represent a real persp object, so buffers can't
-          ;; really be assigned to it, among other quirks. We create a *real* main
-          ;; workspace to fill this role.
+          ;; The default perspective persp-mode creates is special and doesn't
+          ;; represent a real persp object, so buffers can't really be assigned
+          ;; to it, among other quirks. We hide the nil persp...
+          (when (equal (car persp-names-cache) persp-nil-name)
+            (pop persp-names-cache))
+          ;; ...and create a *real* main workspace to fill this role, and hide
+          ;; the nil perspective.
           (unless (or (persp-get-by-name +workspaces-main)
                       ;; Start from 2 b/c persp-mode counts the nil workspace
                       (> (hash-table-count *persp-hash*) 2))