src/java.desktop/windows/native/libawt/windows/awt_Toolkit.cpp

*** 3209,3220 ****
--- 3209,3230 ----
   * the IME functionality in an unexpected state.
   * This function avoids reentrancy issue and must be used for sending of all IME messages
   * instead of SendMessage().
   */
  LRESULT AwtToolkit::InvokeInputMethodFunction(UINT msg, WPARAM wParam, LPARAM lParam) {
+     /*
+      * DND runs on the main thread. So it is  necessary to use SendMessage() to call an IME
+      * function once the DND is active; otherwise a hang is possible since DND may wait for
+      * the IME completion.
+      */
+     if (isInDoDragDropLoop) {
+         return SendMessage(msg, wParam, lParam);
+     } else {
          CriticalSection::Lock lock(m_inputMethodLock);
          if (PostMessage(msg, wParam, lParam)) {
              ::WaitForSingleObject(m_inputMethodWaitEvent, INFINITE);
              return m_inputMethodData;
          }
          return 0;
+     }
  }
+