Subject: [PATCH] Make project-root for vc projects return an absolute path

From: Spencer Baugh <[email-masked]>
Date: Thu, 15 Jun 2023 16:48:05 -0400

Tags: patch

Before this, if a vc project was in the user's home directory,
project-root would be "~/some/path".  This violates the spec of
project-root, which requires an absolute path.  One concrete bug
caused by this is that (project-forget-project "~/some/path") would
work but (project-forget-project "/home/user/some/path") would not.

I ran into this while trying to use file-notify to automatically
discover and forget projects.  file-notify returns truly absolute paths,
so I ran into the aforementioned concrete bug.

In GNU Emacs 29.0.90 (build 8, x86_64-pc-linux-gnu, X toolkit, cairo
 version 1.15.12, Xaw scroll bars) of 2023-06-04 built on
 igm-qws-u22796a
Repository revision: 11d76029db5f0d9e016f247aac24dd430b729c2a
Repository branch: emacs-29
Windowing system distributor 'The X.Org Foundation', version 11.0.12011000
System Description: CentOS Linux 7 (Core)

Configured using:
 'configure --with-x-toolkit=lucid --with-gif=ifavailable'

>From 2c3ed85f857759458130a7b707d9b6f4d2c1ef20 Mon Sep 17 00:00:00 2001
From: Spencer Baugh <[email-masked]>
Date: Thu, 15 Jun 2023 16:45:48 -0400
Subject: [PATCH] Make project-root for vc projects return an absolute path

Before this, if a vc project was in the user's home directory,
project-root would be "~/some/path".  This violates the spec of
project-root, which requires an absolute path.  One concrete bug
caused by this is that (project-forget-project "~/some/path") would
work but (project-forget-project "/home/user/some/path") would not.

* lisp/progmodes/project.el (project-try-vc): Expand root directory
before returning project.
---
 lisp/progmodes/project.el | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/lisp/progmodes/project.el b/lisp/progmodes/project.el
index 2cffc1c0669..72cdb94bce4 100644
--- a/lisp/progmodes/project.el
+++ b/lisp/progmodes/project.el
@@ -689,7 +689,7 @@ project-try-vc
           (let* ((parent (file-name-directory (directory-file-name root))))
             (setq root (vc-call-backend 'Git 'root parent))))
         (when root
-          (setq project (list 'vc backend root))
+          (setq project (list 'vc backend (expand-file-name root)))
           ;; FIXME: Cache for a shorter time.
           (vc-file-setprop dir 'project-vc project)
           project))))
-- 
2.39.3