Add config.x_vt option (fixes #910)

Signed-off-by: AnErrupTion <anerruption@disroot.org>

src/auth.zig

@@ -20,6 +20,7 @@ pub const AuthOptions = struct {
     setup_cmd: []const u8,
     login_cmd: ?[]const u8,
     x_cmd: []const u8,
+    x_vt: ?u8,
     session_pid: std.posix.pid_t,
 };
 
@@ -189,7 +190,7 @@ fn startSession(
         .wayland, .shell, .custom => try executeCmd(log_file, allocator, user_entry.shell.?, options, current_environment.is_terminal, current_environment.cmd),
         .xinitrc, .x11 => if (build_options.enable_x11_support) {
             var vt_buf: [5]u8 = undefined;
-            const vt = try std.fmt.bufPrint(&vt_buf, "vt{d}", .{options.tty});
+            const vt = try std.fmt.bufPrint(&vt_buf, "vt{d}", .{options.x_vt orelse options.tty});
             try executeX11Cmd(log_file, allocator, user_entry.shell.?, user_entry.home.?, options, current_environment.cmd orelse "", vt);
         },
     }

src/config/Config.zig

@@ -92,6 +92,7 @@ vi_default_mode: ViMode = .normal,
 vi_mode: bool = false,
 waylandsessions: []const u8 = build_options.prefix_directory ++ "/share/wayland-sessions",
 x_cmd: []const u8 = build_options.prefix_directory ++ "/bin/X",
+x_vt: ?u8 = null,
 xauth_cmd: []const u8 = build_options.prefix_directory ++ "/bin/xauth",
 xinitrc: ?[]const u8 = "~/.xinitrc",
 xsessions: []const u8 = build_options.prefix_directory ++ "/share/xsessions",

src/main.zig

@@ -1086,6 +1086,7 @@ pub fn main() !void {
                             .setup_cmd = config.setup_cmd,
                             .login_cmd = config.login_cmd,
                             .x_cmd = config.x_cmd,
+                            .x_vt = config.x_vt,
                             .session_pid = session_pid,
                         };