bug#38615: 27.0.50; vc-git: Wrong status in vc-dir after registering directory

[Dmitry Gutov <dgutov@yandex.ru>]

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Hi Andrii,

On 14.12.2019 14:41, Andrii Kolomoiets wrote:
> 0. mkdir test && cd test
>     git init
>     touch file
>     git add file
>     git commit -m "initial"
>     mkdir dir
>     touch dir/file1
> 1. emacs -Q
> 2. C-x v d
>     "dir/" is listed with "unregistered" status.
> 3. v
>     "dir/" has "added" status.
> 4. g
>     "dir/file1" is listed with "up-to-date" status.  Shouldn't it have
>     "added" status?
> 5. g
>     Now "dir/file1" properly has "added" status.
> 
> Also:
> - After step 3 point is moved to word "dir" on second line.
> - Press "n" before step 3 to move point to "dir/". After step 3 "dir/"
>    status is not updated and remains "unregistered".

Thanks for the repro. This problem seems to have been with us for a while.

vc-git's dir-status-files code is a bit hard to follow, but here's a 
patch you can try. I'll commit it in the next few days if nothing comes up.

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diff --git a/lisp/vc/vc-git.el b/lisp/vc/vc-git.el
index 71307cdffd..9e02a820ac 100644
--- a/lisp/vc/vc-git.el
+++ b/lisp/vc/vc-git.el
@@ -521,14 +521,17 @@ vc-git-after-dir-status-stage
       ('ls-files-up-to-date
        (setq next-stage 'ls-files-unknown)
        (while (re-search-forward "\\([0-7]\\{6\\}\\) [0-9a-f]\\{40\\} \\([0-3]\\)\t\\([^\0]+\\)\0" nil t)
-         (let ((perm (string-to-number (match-string 1) 8))
-               (state (match-string 2))
-               (name (match-string 3)))
-           (vc-git-dir-status-update-file
-            git-state name (if (equal state "0")
-                               'up-to-date
-                             'conflict)
-            (vc-git-create-extra-fileinfo perm perm)))))
+         (let* ((perm (string-to-number (match-string 1) 8))
+                (state (match-string 2))
+                (name (match-string 3))
+                (file-info (vc-git-create-extra-fileinfo perm perm)))
+           (if (equal state "0")
+               (unless (gethash name (vc-git-dir-status-state->hash git-state))
+                 ;; `diff-index' has not produced a more precise info.
+                 (vc-git-dir-status-update-file
+                  git-state name 'up-to-date file-info))
+             (vc-git-dir-status-update-file
+              git-state name 'conflict file-info)))))
       ('ls-files-conflict
        (setq next-stage 'ls-files-unknown)
        ;; It's enough to look for "3" to notice a conflict.