Bring back the project--value-in-dir logic

Essentialy revert commit 2389158a31b4a12, restoring the changes
and fixing the conflicts.  Motivated by the problem brought up in
bug#59722 (behavior of project-find-files/regexp when switching
projects).  We should find other ways to improve performance.

* lisp/progmodes/project.el
(project--value-in-dir, project--vc-merge-submodules-p): Restore.
(project-try-vc, project-files, project--vc-list-files)
(project-ignores, project-buffers): Use.

* test/lisp/progmodes/project-tests.el
(project-vc-supports-project-in-different-dir): New test.

* test/lisp/progmodes/project-resources/.dir-locals.el:
* test/lisp/progmodes/project-resources/foo:
* test/lisp/progmodes/project-resources/etc: New files.

1 files changed, 13 insertions, 0 deletions

diff --git a/test/lisp/progmodes/project-tests.el b/test/lisp/progmodes/project-tests.el
index c3b886873d3..e666e3a6fab 100644
--- a/test/lisp/progmodes/project-tests.el
+++ b/test/lisp/progmodes/project-tests.el
@@ -139,4 +139,17 @@ When `project-ignores' includes a name matching project dir."
     (should-not (null project))
     (should (string-match-p "/test/lisp/\\'" (project-root project)))))
 
+(ert-deftest project-vc-supports-project-in-different-dir ()
+  "Check that it picks up dir-locals settings from somewhere else."
+  (skip-unless (eq (vc-responsible-backend default-directory) 'Git))
+  (let* ((dir (ert-resource-directory))
+         (_ (vc-file-clearprops dir))
+         (project-vc-extra-root-markers '(".dir-locals.el"))
+         (project (project-current nil dir)))
+    (should-not (null project))
+    (should (string-match-p "/test/lisp/progmodes/project-resources/\\'" (project-root project)))
+    (should (member "etc" (project-ignores project dir)))
+    (should (equal '(".dir-locals.el" "foo")
+                   (mapcar #'file-name-nondirectory (project-files project))))))
+
 ;;; project-tests.el ends here