--- old/src/java.desktop/share/classes/sun/awt/im/ExecutableInputMethodManager.java	2018-06-15 02:43:18.985822204 +0900
+++ new/src/java.desktop/share/classes/sun/awt/im/ExecutableInputMethodManager.java	2018-06-15 02:43:18.365835255 +0900
@@ -55,6 +55,10 @@
 import java.util.prefs.Preferences;
 import sun.awt.InputMethodSupport;
 import sun.awt.SunToolkit;
+import javax.swing.JDialog;
+import javax.swing.JFrame;
+import javax.swing.JRootPane;
+import java.awt.KeyboardFocusManager;
 
 /**
  * {@code ExecutableInputMethodManager} is the implementation of the
@@ -89,6 +93,7 @@
     // component that is requesting input method switch
     // must be Frame or Dialog
     private Component requestComponent;
+    private Component invokerComponent;
 
     // input context that is requesting input method switch
     private InputContext requestInputContext;
@@ -212,10 +217,23 @@
             return;
 
         requestComponent = comp;
+        if (comp instanceof JDialog) {
+            if (!(comp.getParent() instanceof JFrame))
+                invokerComponent = comp;
+        }
+        if (invokerComponent==null) {
+            invokerComponent = KeyboardFocusManager.getCurrentKeyboardFocusManager()
+                                                   .getFocusOwner();
+            if (invokerComponent !=null && !invokerComponent.isShowing())
+                invokerComponent = comp;
+        }
+        if (invokerComponent==null)
+            invokerComponent = comp;
         notify();
     }
 
     public synchronized void notifyChangeRequestByHotKey(Component comp) {
+        invokerComponent = comp;
         while (!(comp instanceof Frame || comp instanceof Dialog)) {
             if (comp == null) {
                 // no Frame or Dialog found in containment hierarchy.
@@ -288,11 +306,27 @@
 
         if (!hasMultipleInputMethods()) {
             requestComponent = null;
+            invokerComponent = null;
             return;
         }
 
         // initialize pop-up menu
-        selectionMenu = InputMethodPopupMenu.getInstance(requestComponent, selectInputMethodMenuTitle);
+        if (requestComponent != null && requestComponent.equals(invokerComponent)) {
+            selectionMenu = InputMethodPopupMenu.getAWTInstance(requestComponent,
+                                                                selectInputMethodMenuTitle);
+        } else {
+            selectionMenu = InputMethodPopupMenu.getInstance(requestComponent,
+                                                             selectInputMethodMenuTitle);
+        }
+        if (invokerComponent instanceof JRootPane) {
+            if (selectionMenu.isVisible()) {
+                synchronized (this) {
+                    requestComponent = null;
+                    invokerComponent = null;
+                }
+                return;
+            }
+        }
 
         // we have to rebuild the menu each time because
         // some input methods (such as IIIMP) may change
@@ -317,10 +351,23 @@
         }
 
         synchronized (this) {
-            selectionMenu.addToComponent(requestComponent);
-            requestInputContext = currentInputContext;
-            selectionMenu.show(requestComponent, 60, 80); // TODO: get proper x, y...
+            if (requestComponent == null){
+                requestInputContext = currentInputContext;
+                selectionMenu.show(requestComponent, 0, 0);
+            } else {
+                int offsetX = 60;
+                int offsetY = 80;
+                selectionMenu.addToComponent(requestComponent);
+                requestInputContext = currentInputContext;
+                if (requestComponent.getSize().width < offsetX * 2)
+                    offsetX = requestComponent.getSize().width / 2;
+                if (requestComponent.getSize().height < offsetY * 2)
+                    offsetY = requestComponent.getSize().height / 2;
+                selectionMenu.show(requestComponent, offsetX, offsetY);
+            }
             requestComponent = null;
+            invokerComponent = null;
+
         }
     }
 
--- old/src/java.desktop/share/classes/sun/awt/im/InputMethodPopupMenu.java	2018-06-15 02:43:19.835804311 +0900
+++ new/src/java.desktop/share/classes/sun/awt/im/InputMethodPopupMenu.java	2018-06-15 02:43:19.216817341 +0900
@@ -44,6 +44,8 @@
 import javax.swing.JPopupMenu;
 import javax.swing.JMenu;
 import javax.swing.JMenuItem;
+import javax.swing.JWindow;
+import javax.swing.SwingUtilities;
 
 /**
  * {@code InputMethodPopupMenu} provides the popup selection menu
@@ -56,13 +58,20 @@
     // is created.
     static InputMethodPopupMenu getInstance(Component client, String title) {
         if ((client instanceof JFrame) ||
-            (client instanceof JDialog)) {
+            (client instanceof JDialog) ||
+            (client instanceof JWindow)) {
                 return new JInputMethodPopupMenu(title);
         } else {
             return new AWTInputMethodPopupMenu(title);
         }
     }
 
+    static InputMethodPopupMenu getAWTInstance(Component client, String title) {
+        return new AWTInputMethodPopupMenu(title);
+    }
+
+    abstract boolean isVisible();
+
     abstract void show(Component c, int x, int y);
 
     abstract void removeAll();
@@ -175,7 +184,12 @@
         }
     }
 
+    boolean isVisible() {
+        return delegate.isVisible();
+    }
+
     void show(Component c, int x, int y) {
+        SwingUtilities.updateComponentTreeUI(delegate);
         delegate.show(c, x, y);
     }
 
@@ -232,6 +246,10 @@
         }
     }
 
+    boolean isVisible() {
+        return false;
+    }
+
     void show(Component c, int x, int y) {
         delegate.show(c, x, y);
     }