app/seal: leave $DISPLAY as is on host abstract

This helps work around faulty software that misinterprets unix: DISPLAY string.

Signed-off-by: Ophestra <cat@gensokyo.uk>

internal/app/seal_linux.go

@@ -418,9 +418,11 @@ func (seal *outcome) finalise(ctx context.Context, sys sys.State, config *hst.Co
 					}
 				} else {
 					seal.sys.UpdatePermType(system.EX11, socketPath.String(), acl.Read, acl.Write, acl.Execute)
+					if !config.Container.HostAbstract {
 						d = "unix:" + socketPath.String()
 					}
 				}
+			}
 
 			seal.sys.ChangeHosts("#" + seal.user.uid.String())
 			seal.env[display] = d

test/sandbox/case/default.nix

@@ -49,6 +49,7 @@ let
         mapRealUid
         useCommonPaths
         userns
+        hostAbstract
         ;
       enablements = {
         inherit (tc) x11;

test/sandbox/case/device.nix

@@ -26,6 +26,7 @@ in
   useCommonPaths = true;
   userns = false;
   x11 = true;
+  hostAbstract = false;
 
   # 0, PresetStrict
   expectedFilter = {

test/sandbox/case/mapuid.nix

@@ -35,6 +35,7 @@ in
   useCommonPaths = true;
   userns = false;
   x11 = false;
+  hostAbstract = false;
 
   # 0, PresetStrict
   expectedFilter = {

test/sandbox/case/pdlike.nix

@@ -35,6 +35,7 @@ in
   useCommonPaths = false;
   userns = true;
   x11 = false;
+  hostAbstract = false;
 
   # 0, PresetExt | PresetDenyDevel
   expectedFilter = {

test/sandbox/case/preset.nix

@@ -35,6 +35,7 @@ in
   useCommonPaths = false;
   userns = false;
   x11 = false;
+  hostAbstract = false;
 
   # 0, PresetStrict
   expectedFilter = {

test/sandbox/case/tty.nix

@@ -35,6 +35,7 @@ in
   useCommonPaths = true;
   userns = false;
   x11 = true;
+  hostAbstract = true;
 
   # 0, PresetExt | PresetDenyNS | PresetDenyDevel
   expectedFilter = {
@@ -45,7 +46,7 @@ in
   want = {
     env = [
       "DBUS_SESSION_BUS_ADDRESS=unix:path=/run/user/65534/bus"
-      "DISPLAY=unix:/tmp/.X11-unix/X0"
+      "DISPLAY=:0"
       "HOME=/var/lib/hakurei/u0/a2"
       "PULSE_SERVER=unix:/run/user/65534/pulse/native"
       "SHELL=/run/current-system/sw/bin/bash"
@@ -276,7 +277,7 @@ in
     seccomp = true;
 
     try_socket = "/tmp/.X11-unix/X0";
-    socket_abstract = false;
+    socket_abstract = true;
     socket_pathname = true;
   };
 }