make-directory now returns t if dir already exists

This new feature will help fix a copy-directory bug (Bug#58919).
Its implementation does not rely on make-directory handlers
supporting the new feature, as it no longer uses a make-directory
handler H in any way other than (funcall H DIR), thus using
only the intersection of the old and new behavior for handlers.
This will give us time to fix handlers at our leisure.
* lisp/files.el (files--ensure-directory): New arg MKDIR.
All uses changed.
(files--ensure-directory, make-directory):
Return non-nil if DIR is already a directory.  All uses changed.
* test/lisp/files-tests.el (files-tests-make-directory):
Test new return-value convention.

1 files changed, 3 insertions, 3 deletions

diff --git a/test/lisp/files-tests.el b/test/lisp/files-tests.el
index efafb5583ac..b9fbeb8a4e0 100644
--- a/test/lisp/files-tests.el
+++ b/test/lisp/files-tests.el
@@ -1261,11 +1261,11 @@ works as expected if the default directory is quoted."
            (a/b (concat dirname "a/b")))
       (write-region "" nil file)
       (should-error (make-directory "/"))
-      (should-not (make-directory "/" t))
+      (should (make-directory "/" t))
       (should-error (make-directory dir))
-      (should-not (make-directory dir t))
+      (should (make-directory dir t))
       (should-error (make-directory dirname))
-      (should-not (make-directory dirname t))
+      (should (make-directory dirname t))
       (should-error (make-directory file))
       (should-error (make-directory file t))
       (should-not (make-directory subdir1))