src/java.desktop/share/classes/javax/swing/JRootPane.java

@@ -920,11 +920,11 @@
             } else {
                 // This is silly, but should stop an overflow error
                 rd = new Dimension(Integer.MAX_VALUE,
                         Integer.MAX_VALUE - i.top - i.bottom - mbd.height - 1);
             }
-            return new Dimension(Math.min(rd.width, mbd.width) + i.left + i.right,
+            return new Dimension(Math.max(rd.width, mbd.width) + i.left + i.right,
                                          rd.height + mbd.height + i.top + i.bottom);
         }
 
         /**
          * Instructs the layout manager to perform the layout for the specified