fix: keep location history registered after a savehist setq

A one-time add-to-list put wttrin--location-history into savehist-additional-variables when savehist loaded. Any user who later setqs that list, a common config pattern for curating which histories persist, replaces it and drops the entry. The search history then silently never saves.

Re-assert the registration on savehist-save-hook, which runs at the top of every savehist-save. The variable is now in the list whenever a save happens, regardless of init order or a clobbering setq. Restore was never affected, since savehist reloads the value from explicit setq forms in its file.

The README persistence note now reflects this: the variable stays registered even if you set savehist-additional-variables yourself.

1 files changed, 1 insertions, 1 deletions

diff --git a/README.org b/README.org
index 8fd3fd2..658c4ed 100644
--- a/README.org
+++ b/README.org
@@ -139,7 +139,7 @@ History is capped at =wttrin-location-history-max= entries (default 20); the old
   (setq wttrin-location-history-max 20)
 #+end_src
 
-To persist the history across Emacs restarts, enable the built-in =savehist-mode= (Wttrin registers its history variable automatically). Without it, history lasts for the session only.
+To persist the history across Emacs restarts, enable the built-in =savehist-mode=. Wttrin keeps its history variable registered automatically, even if you set =savehist-additional-variables= yourself, so there is nothing else to configure. Without =savehist-mode=, history lasts for the session only.
 
 #+begin_src emacs-lisp
   (savehist-mode 1)