* lisp/find-file.el (ff-other-file-alist): Doc fix. (Bug#57325)

diff --git a/lisp/find-file.el b/lisp/find-file.el
index 614ff420f255767e240fb9d6de9a492d58ecfaf3..e9aba883ae1840acd9a8783e45b826784ef906bc 100644 (file)
--- a/lisp/find-file.el
+++ b/lisp/find-file.el
@@ -204,7 +204,12 @@ The list of extensions should contain the most used extensions before the
 others, since the search algorithm searches sequentially through each
 directory specified in `ff-search-directories'.  If a file is not found,
 a new one is created with the first matching extension (`.cc' yields `.hh').
-This alist should be set by the major mode."
+This alist should be set by the major mode.
+
+Note: if an element of the alist names a FUNCTION as its cdr, that
+function must return a non-nil list of file-name extensions.  It cannot
+return nil, nor can it signal in any way a failure to find a suitable
+list of extensions."
   :type '(choice (repeat (list regexp (choice (repeat string) function)))
                 symbol))