--- old/src/java.desktop/windows/native/libawt/windows/awt_Toolkit.cpp	2020-08-28 16:54:34.000000000 +0100
+++ new/src/java.desktop/windows/native/libawt/windows/awt_Toolkit.cpp	2020-08-28 16:54:33.000000000 +0100
@@ -3211,10 +3211,20 @@
  * instead of SendMessage().
  */
 LRESULT AwtToolkit::InvokeInputMethodFunction(UINT msg, WPARAM wParam, LPARAM lParam) {
-    CriticalSection::Lock lock(m_inputMethodLock);
-    if (PostMessage(msg, wParam, lParam)) {
-        ::WaitForSingleObject(m_inputMethodWaitEvent, INFINITE);
-        return m_inputMethodData;
+    /*
+     * 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;
     }
-    return 0;
 }
+