Improve previous apropos-documentation-check-elc-file change

* lisp/apropos.el (apropos-documentation-check-elc-file): Add
comment to explain what's going on and expand to lisp-directory
(bug#55492).

diff --git a/lisp/apropos.el b/lisp/apropos.el
index 428aeb15412784e11e790335b08b94f982c30af2..0b84f9fa63b6a3cbcb85f7961a3860120f6a4ada 100644 (file)
--- a/lisp/apropos.el
+++ b/lisp/apropos.el
@@ -1055,8 +1055,11 @@ non-nil."
       (setq sepa (goto-char sepb)))))
 
 (defun apropos-documentation-check-elc-file (file)
+  ;; .elc files have the location of the file specified as #$, but for
+  ;; built-in files, that's a relative name (while for the rest, it's
+  ;; absolute).  So expand the name in the former case.
   (unless (file-name-absolute-p file)
-    (setq file (locate-library file)))
+    (setq file (expand-file-name file lisp-directory)))
   (if (or (member file apropos-files-scanned)
           (not (file-exists-p file)))
       nil