From f5182ffc4211860348fc7c78e0ba3a9d36f13aeb Mon Sep 17 00:00:00 2001
From: Rodney Lorrimar <dev@rodney.id.au>
Date: Thu, 9 Nov 2023 17:27:45 +0800
Subject: [PATCH] emacs: Fix socket activation

---
 modules/services/emacs.nix                         | 14 +++++++++++++-
 .../services/emacs/emacs-socket-emacs.socket       |  2 ++
 2 files changed, 15 insertions(+), 1 deletion(-)

diff --git a/modules/services/emacs.nix b/modules/services/emacs.nix
index 394e3659..d319abf0 100644
--- a/modules/services/emacs.nix
+++ b/modules/services/emacs.nix
@@ -205,9 +205,21 @@ in {
           FileDescriptorName = "server";
           SocketMode = "0600";
           DirectoryMode = "0700";
+          # This prevents the service from immediately starting again
+          # after being stopped, due to the function
+          # `server-force-stop' present in `kill-emacs-hook', which
+          # calls `server-running-p', which opens the socket file.
+          FlushPending = true;
         };
 
-        Install = { WantedBy = [ "sockets.target" ]; };
+        Install = {
+          WantedBy = [ "sockets.target" ];
+          # Adding this Requires= dependency ensures that systemd
+          # manages the socket file, in the case where the service is
+          # started when the socket is stopped.
+          # The socket unit is implicitly ordered before the service.
+          RequiredBy = [ "emacs.service" ];
+        };
       };
     })
   ]);
diff --git a/tests/modules/services/emacs/emacs-socket-emacs.socket b/tests/modules/services/emacs/emacs-socket-emacs.socket
index 7fffcb0d..843d87fe 100644
--- a/tests/modules/services/emacs/emacs-socket-emacs.socket
+++ b/tests/modules/services/emacs/emacs-socket-emacs.socket
@@ -1,9 +1,11 @@
 [Install]
+RequiredBy=emacs.service
 WantedBy=sockets.target
 
 [Socket]
 DirectoryMode=0700
 FileDescriptorName=server
+FlushPending=true
 ListenStream=%t/emacs/server
 SocketMode=0600