support using different login shell

res/config.ini

@@ -267,6 +267,11 @@ lang = en
 # You can also set environment variables in there, they'll persist until logout
 login_cmd = null
 
+# SHELL to use when logging in
+# If null, it will use the default login shell
+# Important: it must be an absolute path!
+login_shell = null
+
 # Path for login.defs file (used for listing all local users on the system on
 # Linux)
 login_defs_path = /etc/login.defs

src/auth.zig

@@ -19,6 +19,7 @@ pub const AuthOptions = struct {
     xauth_cmd: []const u8,
     setup_cmd: []const u8,
     login_cmd: ?[]const u8,
+    login_shell: ?[]const u8,
     x_cmd: []const u8,
     session_pid: std.posix.pid_t,
 };
@@ -417,7 +418,7 @@ fn executeX11Cmd(log_file: *LogFile, allocator: std.mem.Allocator, shell: []cons
     var buf: [4]u8 = undefined;
     const display_name = try std.fmt.bufPrint(&buf, ":{d}", .{display_num});
 
-    const shell_z = try allocator.dupeZ(u8, shell);
+    const shell_z = try allocator.dupeZ(u8, options.login_shell orelse shell);
     defer allocator.free(shell_z);
 
     try log_writer.writeAll("[x11] creating xauth file\n");
@@ -491,7 +492,7 @@ fn executeCmd(global_log_file: *LogFile, allocator: std.mem.Allocator, shell: []
     }
     defer if (maybe_log_file) |log_file| log_file.close();
 
-    const shell_z = try allocator.dupeZ(u8, shell);
+    const shell_z = try allocator.dupeZ(u8, options.login_shell orelse shell);
     defer allocator.free(shell_z);
 
     var cmd_buffer: [1024]u8 = undefined;

src/config/Config.zig

@@ -66,6 +66,7 @@ initial_info_text: ?[]const u8 = null,
 input_len: u8 = 34,
 lang: []const u8 = "en",
 login_cmd: ?[]const u8 = null,
+login_shell: ?[]const u8 = null,
 login_defs_path: []const u8 = "/etc/login.defs",
 logout_cmd: ?[]const u8 = null,
 ly_log: []const u8 = "/var/log/ly.log",

src/main.zig

@@ -1084,6 +1084,7 @@ pub fn main() !void {
                             .xauth_cmd = config.xauth_cmd,
                             .setup_cmd = config.setup_cmd,
                             .login_cmd = config.login_cmd,
+                            .login_shell = config.login_shell,
                             .x_cmd = config.x_cmd,
                             .session_pid = session_pid,
                         };