CURSORINFO.flags should be checked before capturing its bitmap

webrtc/modules/desktop_capture/mouse_cursor_monitor_win.cc

 /*
  *  Copyright (c) 2013 The WebRTC project authors. All Rights Reserved.
  *
  *  Use of this source code is governed by a BSD-style license
  *  that can be found in the LICENSE file in the root of the source
  *  tree. An additional intellectual property rights grant can be found
  *  in the file PATENTS.  All contributing project authors may
  *  be found in the AUTHORS file in the root of the source tree.
  */
 
@@ skipping 74 matching lines @@
 void MouseCursorMonitorWin::Capture() {
   assert(callback_);
 
   CURSORINFO cursor_info;
   cursor_info.cbSize = sizeof(CURSORINFO);
   if (!GetCursorInfo(&cursor_info)) {
     LOG_F(LS_ERROR) << "Unable to get cursor info. Error = " << GetLastError();
     return;
   }
 
-  if (last_cursor_ != cursor_info.hCursor) {
-    last_cursor_ = cursor_info.hCursor;
+  if (cursor_info.flags == CURSOR_SHOWING &&

[Sergey Ulanov, 2016/05/10 20:51:15]

I still think that wont do the right thing. Particularly in Desktop Capture API,
if the cursor hidden we don't want it to be rendered on the screen by
DesktopAndCursorComposer. With this change DesktopAndCursorComposer will not be
notified that the cursor is hidden and it will keep drawing it.
Also in CRD we want to default to arrow in that case instead of using the last
non-hidden cursor.

[Sergey Ulanov, 2016/05/10 20:58:12]

Actually looking at this again I see your point - the Desktop Capture API should
work correctly as OnMouseCursorPosition() will be called with state=OUTSIDE. But
I still think the behavior in CRD (when mode==SHAPE_ONLY) is incorrect.

[Hzj_jie, 2016/05/11 00:55:49]

Done.

[Hzj_jie, 2016/05/11 00:55:49]

Based on our discussion, we will do this,
1. Always return a cursor info to the client. If Windows does not return a valid
cursor, we will return a default one.
2. Add a field in CursorShapeInfo to indicate whether currently the cursor is
shown or not.

+      last_cursor_ != cursor_info.hCursor) {
     // Note that |cursor_info.hCursor| does not need to be freed.
     std::unique_ptr<MouseCursor> cursor(
         CreateMouseCursorFromHCursor(desktop_dc_, cursor_info.hCursor));
-    if (cursor.get())
+    if (cursor) {
+      last_cursor_ = cursor_info.hCursor;
       callback_->OnMouseCursor(cursor.release());
+    } else {
+      last_cursor_ = NULL;
+    }
   }
 
   if (mode_ != SHAPE_AND_POSITION)
     return;
 
   DesktopVector position(cursor_info.ptScreenPos.x, cursor_info.ptScreenPos.y);
   bool inside = cursor_info.flags == CURSOR_SHOWING;
 
   if (window_) {
     DesktopRect original_rect;
@@ skipping 54 matching lines @@
   return new MouseCursorMonitorWin(reinterpret_cast<HWND>(window));
 }
 
 MouseCursorMonitor* MouseCursorMonitor::CreateForScreen(
     const DesktopCaptureOptions& options,
     ScreenId screen) {
   return new MouseCursorMonitorWin(screen);
 }
 
 }  // namespace webrtc