fix: allow logon screen password, on lock screen (#11566)

Signed-off-by: fufesou <linlong1266@gmail.com>

src/platform/linux.rs

@@ -623,6 +623,31 @@ pub fn is_prelogin() -> bool {
     n < 4 && n > 1
 }
 
+// Check "Lock".
+// "Switch user" can't be checked, because `get_values_of_seat0(&[0])` does not return the session.
+// The logged in session is "online" not "active".
+// And the "Switch user" screen is usually Wayland login session, which we do not support.
+pub fn is_locked() -> bool {
+    if is_prelogin() {
+        return false;
+    }
+
+    let values = get_values_of_seat0(&[0]);
+    // Though the values can't be empty, we still add check here for safety.
+    // Because we cannot guarantee whether the internal implementation will change in the future.
+    // https://github.com/rustdesk/hbb_common/blob/ebb4d4a48cf7ed6ca62e93f8ed124065c6408536/src/platform/linux.rs#L119
+    if values.is_empty() {
+        log::debug!("Failed to check is locked, values vector is empty.");
+        return false;
+    }
+    let session = &values[0];
+    if session.is_empty() {
+        log::debug!("Failed to check is locked, session is empty.");
+        return false;
+    }
+    is_session_locked(session)
+}
+
 pub fn is_root() -> bool {
     crate::username() == "root"
 }