Fix problems with org-attach-git, failed tests

Ref. mail "[O] git-annex-related org-attach tests failing on
master"
https://lists.gnu.org/archive/html/emacs-orgmode/2019-09/msg00030.html
* lisp/org-attach-git.el (org-attach-git-commit): Add optional
argument to function contract to make it work with
`org-attach-after-change-hook'.  Even though that argument is
not used in the actual code (due to legacy functionality).

* testing/lisp/test-org-attach.el
(test-org-attach/dired-attach-to-next-best-subtree/1)
(test-org-attach/dired-attach-to-next-best-subtree/2):
Modify tests to also work if user has git-annex installed

* testing/lisp/test-org-attach-git.el
(test-org-attach-git/use-annex): Correct errors from previous
commit, where git-annex was refactored out from org-attach
into it's separate module.

lisp/org-attach-git.el

@@ -23,10 +23,9 @@
 
 ;;; Commentary:
 
-;; An extention to org-attach.  If the attachment-directory to an
-;; outline node (using either DIR or ID) is initialized as a Git
-;; repository, then org-attach-git will automatically commit changes
-;; when it sees them.
+;; An extention to org-attach.  If `org-attach-id-dir' is initialized
+;; as a Git repository, then org-attach-git will automatically commit
+;; changes when it sees them.  Requires git-annex.
 
 ;;; Code:
 
@@ -81,9 +80,12 @@ Signals an error if the file content is not available and it was not retrieved."
 	(message "Running git annex get \"%s\"." path-relative)
 	(call-process "git" nil nil nil "annex" "get" path-relative)))))
 
-(defun org-attach-git-commit ()
+(defun org-attach-git-commit (&optional attach-dir)
   "Commit changes to git if `org-attach-id-dir' is properly initialized.
-This checks for the existence of a \".git\" directory in that directory."
+This checks for the existence of a \".git\" directory in that directory.
+
+Takes one optional argument ATTACH-DIR for the sake of being
+compatible with hook `org-attach-after-change-hook'."
   (let* ((dir (expand-file-name org-attach-id-dir))
 	 (git-dir (vc-git-root dir))
 	 (use-annex (org-attach-git-use-annex))

testing/lisp/test-org-attach-git.el

@@ -33,12 +33,12 @@
 	   ,@body))))
 
 (ert-deftest test-org-attach-git/use-annex ()
-  (test-org-attach-annex/with-annex
+  (test-org-attach-git/with-annex
    (let ((org-attach-git-annex-cutoff 1))
-     (should (org-attach-use-annex)))
+     (should (org-attach-git-use-annex)))
 
    (let ((org-attach-git-annex-cutoff nil))
-     (should-not (org-attach-use-annex))))
+     (should-not (org-attach-git-use-annex))))
 
   ;; test with non annex directory
   (let ((tmpdir (make-temp-file "org-annex-test" t "/")))
@@ -46,11 +46,11 @@
 	 (let ((default-directory tmpdir)
 	       (org-attach-id-dir tmpdir))
 	   (shell-command "git init")
-	   (should-not (org-attach-use-annex)))
+	   (should-not (org-attach-git-use-annex)))
        (delete-directory tmpdir 'recursive))))
 
 (ert-deftest test-org-attach-git/get-maybe ()
-  (test-org-attach-annex/with-annex
+  (test-org-attach-git/with-annex
    (let ((path (expand-file-name "test-file"))
 	 (annex-dup (make-temp-file "org-annex-test" t "/")))
      (with-temp-buffer
@@ -71,21 +71,21 @@
      (shell-command "git annex drop --force test-file")
      ;; test getting the file from the dup when we should ALWAYS get
      (should (not (file-exists-p (file-symlink-p (expand-file-name "test-file")))))
-     (let ((org-attach-annex-auto-get t))
-       (org-attach-annex-get-maybe (expand-file-name "test-file"))
+     (let ((org-attach-git-annex-auto-get t))
+       (org-attach-git-annex-get-maybe (expand-file-name "test-file"))
        ;; check that the file has the right contents
        (with-temp-buffer
 	 (insert-file-contents path)
 	 (should (string-equal "hello world\n" (buffer-string)))))
      ;; test getting the file from the dup when we should NEVER get
      (shell-command "git annex drop --force test-file")
-     (let ((org-attach-annex-auto-get nil))
-       (should-error (org-attach-annex-get-maybe (expand-file-name "test-file"))))
-     (let ((org-attach-annex-auto-get 'ask)
+     (let ((org-attach-git-annex-auto-get nil))
+       (should-error (org-attach-git-annex-get-maybe (expand-file-name "test-file"))))
+     (let ((org-attach-git-annex-auto-get 'ask)
 	   (called nil))
        (cl-letf (((symbol-function 'y-or-n-p)
 		  (lambda (_) (setq called 'was-called) t)))
-	 (org-attach-annex-get-maybe (expand-file-name "test-file"))
+	 (org-attach-git-annex-get-maybe (expand-file-name "test-file"))
 	 ;; check that the file has the right contents
 	 (with-temp-buffer
 	   (insert-file-contents path)

testing/lisp/test-org-attach.el

@@ -108,12 +108,14 @@
 (ert-deftest test-org-attach/dired-attach-to-next-best-subtree/1 ()
   "Attach file at point in dired to subtree."
   (should
-   (let ((a-filename (make-temp-file "a"))) ; file is an attach candidate.
+   (let ((a-filename (make-temp-file "a")) ; file is an attach candidate.
+	 (org-attach-id-dir "data/"))
      (unwind-protect
 	 (org-test-with-temp-text-in-file
 	     "* foo   :foo:"
 	   (split-window)
-	  (dired temporary-file-directory)
+	   (let ((org-buffer (current-buffer))
+		 (dired-buffer (dired temporary-file-directory)))
 	     (cl-assert (eq 'dired-mode major-mode))
 	     (revert-buffer)
 	     (dired-goto-file a-filename)
@@ -121,7 +123,8 @@
 	     (call-interactively #'org-attach-dired-to-subtree)
 					; check
 	     (delete-window)
-	  (cl-assert (eq 'org-mode major-mode))
+	     (switch-to-buffer org-buffer)
+	     (cl-assert (eq 'org-mode major-mode)))
 	   (beginning-of-buffer)
 	   (search-forward "* foo")
 					; expectation.  tag ATTACH has been appended.
@@ -136,12 +139,14 @@
   "Attach 2 marked files."
   (should
    (let ((a-filename (make-temp-file "a"))
-	 (b-filename (make-temp-file "b"))) ; attach candidates.
+	 (b-filename (make-temp-file "b")) ; attach candidates.
+	 (org-attach-id-dir "data/"))
      (unwind-protect
 	 (org-test-with-temp-text-in-file
 	  "* foo"
 	  (split-window)
-	  (dired temporary-file-directory)
+	  (let ((org-buffer (current-buffer))
+		(dired-buffer (dired temporary-file-directory)))
 	    (cl-assert (eq 'dired-mode major-mode))
 	    (revert-buffer)
 	    (dired-goto-file a-filename)
@@ -152,6 +157,7 @@
 	    (call-interactively #'org-attach-dired-to-subtree)
 					; check
 	    (delete-window)
+	    (switch-to-buffer org-buffer))
 	  (cl-assert (eq 'org-mode major-mode))
 	  (beginning-of-buffer)
 	  (search-forward "* foo")