diagnostics for IDEA-143603 (unable to paste text copied from other applications)

platform/platform-impl/src/com/intellij/ide/IdeEventQueue.java

@@ -521,6 +521,8 @@ public class IdeEventQueue extends EventQueue {
     }
 
     myEventCount++;
+    
+    traceClipboardEvents(e);
 
     if (e instanceof WindowEvent) {
       processAppActivationEvents((WindowEvent)e);
@@ -648,6 +650,40 @@ public class IdeEventQueue extends EventQueue {
     }
   }
 
+  private static final Field ourInvocationEventRunnableAccessor;
+  
+  static {
+    Field field = null;
+    if (Registry.is("trace.clipboard.events") && SystemInfo.isJavaVersionAtLeast("1.8.0_60")) {
+      try {
+        field = InvocationEvent.class.getDeclaredField("runnable");
+        field.setAccessible(true);
+      }
+      catch (Exception e) {
+        LOG.warn("Error creating accessor for java.awt.event.InvocationEvent.runnable field", e);
+      }
+    }
+    ourInvocationEventRunnableAccessor = field;
+  }
+  
+  private static void traceClipboardEvents(AWTEvent e) {
+    if (ourInvocationEventRunnableAccessor != null && e instanceof InvocationEvent && e.getClass().getName().equals("sun.awt.PeerEvent")) {
+      try {
+        Object r = ourInvocationEventRunnableAccessor.get(e);
+        if (r != null) {
+          String className = r.getClass().getName();
+          // This check for event constructed in SunClipboard.lostOwnershipLater() (known to work with JDK 8u60) 
+          if (className.contains("sun.awt.datatransfer.SunClipboard") && className.contains("Lambda")) {
+            LOG.info("Clipboard has been set by other application");
+          }
+        }
+      }
+      catch (Exception ex) {
+        LOG.warn("Error accessing java.awt.event.InvocationEvent.runnable field");
+      }
+    }
+  }
+
   private MouseEvent lastClickEvent = null;
   private long lastClickTime = 0L;
 

platform/util/resources/misc/registry.properties

@@ -653,4 +653,8 @@ ruby.remote.debugger.supports.catchpoint.removal=true
 
 use.read.action.to.init.service=true
 
-ide.mac.new.color.picker=false
+ide.mac.new.color.picker=false
+
+trace.clipboard.events=false
+trace.clipboard.events.description=Enable detection and logging of OS notifications about external clipboard changes
+trace.clipboard.events.restartRequired=true