fix(mail): default cj/custom-keymap so the file byte-compiles standalone

cj/custom-keymap is defined in keybindings.el, which init.el loads
before mail-config.el. The use-package org-msg :preface block calls
keymap-set on it, and use-package wraps :preface in eval-and-compile.
So byte-compiling mail-config.el on its own tries to call keymap-set
when cj/custom-keymap is still void.

Wrapping a defvar with a make-sparse-keymap default in eval-and-compile
gives the symbol a value during compilation. At runtime keybindings.el
has already populated the real keymap, so defvar does nothing.

1 files changed, 8 insertions, 0 deletions

diff --git a/modules/mail-config.el b/modules/mail-config.el
index 93989f975..0d9fe450c 100644
--- a/modules/mail-config.el
+++ b/modules/mail-config.el
@@ -26,6 +26,14 @@
 
 (require 'user-constants)
 
+;; cj/custom-keymap's real binding is in keybindings.el, which init.el loads
+;; first. The use-package org-msg :preface below wraps in eval-and-compile, so
+;; standalone byte-compile evaluates `keymap-set` on it at compile time. This
+;; shim defines cj/custom-keymap then; defvar is a no-op once the real keymap
+;; is in place at load time.
+(eval-and-compile
+  (defvar cj/custom-keymap (make-sparse-keymap)))
+
 ;; -------------------- HarfBuzz Crash Fix: Disable Composition ---------------
 ;; Disable auto-composition in mu4e headers to prevent SIGSEGV from HarfBuzz
 ;; when shaping emoji characters in email subjects. See Commentary above.