Handle nil load-path element in read-library-name

* lisp/emacs-lisp/find-func.el (read-library-name): Fix handling of
nil 'load-path' element.  (Bug#41998)

Copyright-paperwork-exempt: yes

diff --git a/lisp/emacs-lisp/find-func.el b/lisp/emacs-lisp/find-func.el
index e35db56550d821ab1a98ef9f9738b7fb5132440e..56b3e32a3e30ac43e09c1ea8fe1d72a399803bd4 100644 (file)
--- a/lisp/emacs-lisp/find-func.el
+++ b/lisp/emacs-lisp/find-func.el
@@ -292,12 +292,13 @@ if non-nil)."
                          (find-library-suffixes)
                          "\\|"))
          (table (cl-loop for dir in (or find-function-source-path load-path)
-                         when (file-readable-p dir)
+                         for dir-or-default = (or dir default-directory)
+                         when (file-readable-p dir-or-default)
                          append (mapcar
                                  (lambda (file)
                                    (replace-regexp-in-string suffix-regexp
                                                              "" file))
-                                 (directory-files dir nil
+                                 (directory-files dir-or-default nil
                                                   suffix-regexp))))
          (def (if (eq (function-called-at-point) 'require)
                   ;; `function-called-at-point' may return 'require