getty: improve argument handling when launching login

Add explicit argument separator before username to ensure correct
parsing of the login command regardless of username format.  This
follows best practices for command execution and prevents unexpected
behavior when processing special characters in usernames.

Signed-off-by: Joachim Wiberg <[email protected]>

Author: troglobit

src/getty.c

@@ -312,9 +312,9 @@ static int exec_login(char *name)
 	struct stat st;
 
 	if (passenv)
-		execl(_PATH_LOGIN, _PATH_LOGIN, "-p", name, NULL);
+		execl(_PATH_LOGIN, _PATH_LOGIN, "-p", "--", name, NULL);
 	else
-		execl(_PATH_LOGIN, _PATH_LOGIN, name, NULL);
+		execl(_PATH_LOGIN, _PATH_LOGIN, "--", name, NULL);
 
 	/*
 	 * Failed to exec login, should not happen on normal systems.