emacs-30 608526a91a0: Revert "* lisp/help-fns.el (help-definition-prefixes): Don't delete the hashtable"

[Eli Zaretskii]

branch: emacs-30
commit 608526a91a0e0f0287448eb88b0bd11c78fa8688
Author: Eli Zaretskii <eliz@gnu.org>
Commit: Eli Zaretskii <eliz@gnu.org>

    Revert "* lisp/help-fns.el (help-definition-prefixes): Don't delete the 
hashtable"
    
    This reverts commit 45ae4de0e7ce99c88c62f940f605bca693b8e33f.
    It did not fix a regression or even a user-visible bug, and
    it caused bug#72787.
    
    Do not merge to master.
---
 lisp/help-fns.el | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/lisp/help-fns.el b/lisp/help-fns.el
index c03593bcb69..1ffe1b16588 100644
--- a/lisp/help-fns.el
+++ b/lisp/help-fns.el
@@ -85,14 +85,14 @@ current help buffer.")
 
 (defun help-definition-prefixes ()
   "Return the up-to-date radix-tree form of `definition-prefixes'."
-  (when (and (null help-definition-prefixes)
-             (> (hash-table-count definition-prefixes) 0))
+  (when (> (hash-table-count definition-prefixes) 0)
     (maphash (lambda (prefix files)
                (let ((old (radix-tree-lookup help-definition-prefixes prefix)))
                  (setq help-definition-prefixes
                        (radix-tree-insert help-definition-prefixes
                                           prefix (append old files)))))
-             definition-prefixes))
+             definition-prefixes)
+    (clrhash definition-prefixes))
   help-definition-prefixes)
 
 (defun help--loaded-p (file)