Fix disappearing modeline due to loss of state

TODO.org

@@ -1,12 +1,12 @@
 #+TITLE: DOOM Emacs Changelog
 
-** Unreleased [37/52]
+** Unreleased [38/52]
 + [-] app/finance
 + [-] app/crm
 + [-] Improve send-to-REPL workflow
 + [ ] Update screenshots
 + [ ] Fix lack of syntax highlighting in ~:x~ scratch buffer
-+ [ ] Fix modeline disappearing due to loss of state (~doom--modeline-format~ being killed on major mode change)
++ [X] Fix modeline disappearing due to loss of state (~doom--modeline-format~ being killed on major mode change)
 + [0/4] Investigate potential plugins
   + [ ] feature/version-control: [[https://github.com/pidu/git-timemachine][git-timemachine]] (replacement for vc-annotate)
   + [ ] lang/org: [[https://github.com/Malabarba/latex-extra][orgit]] (org links to magit buffers)

core/core-popups.el

@@ -172,9 +172,9 @@ for :align t on every rule."
                (doom-hide-modeline-mode +1))
               ((and (symbolp modeline)
                     (not (eq modeline 't)))
-               (let ((doom--modeline-format (doom-modeline modeline)))
+               (setq-local doom--modeline-format (doom-modeline modeline))
                (when doom--modeline-format
-                   (doom-hide-modeline-mode +1))))))
+                 (doom-hide-modeline-mode +1)))))
     ;; show modeline
     (when doom-hide-modeline-mode
       (doom-hide-modeline-mode -1))))

core/core-ui.el

@@ -49,7 +49,7 @@
 (add-hook! isearch-mode-end (setq echo-keystrokes 0.02))
 
 ;; A minor mode for toggling the mode-line
-(defvar doom--modeline-format nil
+(defvar-local doom--modeline-format nil
   "The modeline format to use when `doom-hide-modeline-mode' is active. Don't
 set this directly. Bind it in `let' instead.")
 (defvar-local doom--old-modeline-format nil
@@ -66,6 +66,7 @@ disabled.")
           doom--old-modeline-format nil))
   (force-mode-line-update))
 ;; Ensure major-mode or theme changes don't overwrite these variables
+(put 'doom--modeline-format 'permanent-local t)
 (put 'doom--old-modeline-format 'permanent-local t)
 (put 'doom-hide-modeline-mode 'permanent-local t)