[fix] restore remote cursors on Windows without a physical mouse

libs/wire/include/remote_action.h

@@ -73,6 +73,24 @@ struct KeyboardState {
   KeyboardStateKey pressed_keys[kMaxKeyboardStateKeys];
 };
 
+// Optional presentation metadata. Zero preserves pre-metadata peers' behavior.
+enum class CursorRenderMode : uint8_t {
+  legacy = 0,
+  separate,
+  embedded,
+  hidden,
+  unknown,
+};
+
+enum class CursorHiddenReason : uint8_t {
+  unspecified = 0,
+  system_hidden,
+  system_suppressed,
+  no_pointing_device,
+  sampling_failed,
+  secure_desktop_pending,
+};
+
 struct CursorState {
   uint32_t seq;
   bool visible;
@@ -89,6 +107,10 @@ struct CursorState {
   // Shape-only updates set this to false so cursor appearance can remain
   // responsive while position feedback to the input source is suppressed.
   bool position_update;
+  // Keep visible/shape for old receivers; new receivers can distinguish an
+  // embedded pointer from a hidden pointer and an unavailable sample.
+  CursorRenderMode render_mode;
+  CursorHiddenReason hidden_reason;
 };
 
 struct HostInfo {

libs/wire/src/remote_action.cpp

@@ -91,7 +91,9 @@ std::string RemoteAction::ToJson(const RemoteAction& action) {
            {"visual_offset_x", action.cs.visual_offset_x},
            {"visual_offset_y", action.cs.visual_offset_y},
            {"display_id", action.cs.display_id},
-           {"position_update", action.cs.position_update}};
+           {"position_update", action.cs.position_update},
+           {"render_mode", static_cast<int>(action.cs.render_mode)},
+           {"hidden_reason", static_cast<int>(action.cs.hidden_reason)}};
       break;
     case ControlType::audio_capture:
       object["audio_capture"] = action.a;
@@ -197,6 +199,19 @@ bool RemoteAction::FromJson(const std::string& json_string,
         output.cs.seq = cursor_state_object.at("seq").get<uint32_t>();
         output.cs.visible = cursor_state_object.at("visible").get<bool>();
         output.cs.shape = static_cast<RemoteCursorShape>(shape);
+        const int mode = cursor_state_object.value("render_mode", 0);
+        const int reason = cursor_state_object.value("hidden_reason", 0);
+        // Unknown extensions from a newer peer fall back to visible/shape.
+        output.cs.render_mode =
+            mode >= 0 && mode <= static_cast<int>(CursorRenderMode::unknown)
+                ? static_cast<CursorRenderMode>(mode)
+                : CursorRenderMode::legacy;
+        output.cs.hidden_reason =
+            reason >= 0 &&
+                    reason <= static_cast<int>(
+                                  CursorHiddenReason::secure_desktop_pending)
+                ? static_cast<CursorHiddenReason>(reason)
+                : CursorHiddenReason::unspecified;
         output.cs.position_valid =
             cursor_state_object.value("position_valid", false);
         output.cs.x = cursor_state_object.value("x", 0.5f);