Bug 1468 - SIGSEGV on use after free when destroying NEWT Window/Display via a native dispatch'ed event like key/mouse/touch input

SIGSEGV on use after free of native X11 Display* at XEventsQueued in DisplayDriver.DispatchMessages0.

This potentially happens when an application destroys
the NEWT Window/Display from an action being called directly
from DisplayDriver.DispatchMessages0 (itself), i.e. keyboard or mouse input.

DisplayDriver.DispatchMessages0 stays in the event loop and the next
XEventsQueued call causes a SIGSEGV due to already deleted
display driver connection and hence invalid native X11 Display*.

This issue also exist for other Windowing System drivers,
where the native (dispatch) method sticks to a loop
and still (re)uses the window or display handle.

One is WindowsWindow, where touch events are looped,
but such handler could have closed the window.

Querying the status of a window / display instance before dispatching
is not be good enough
- resource could already be GC'ed, so we also would need to query jobject status
- would imply an addition Java callback

+++

This fix: Having the Java callbacks return
a boolean with the value Window.isNativeValid().

This way the dispatch logic
- can bail out right away w/o using the resource anymore

- must be reviewed by myself due to changed Call{Void->Boolean}*(..)
  invocation change.
  This review shall resolve potential similar issues.

+++

Tested on X11/Linux/GNU, Windows and MacOS
with new TestDestroyGLAutoDrawableNewtAWT,
which tests all destruction invocation variants.

2 files changed, 4 insertions, 3 deletions

diff --git a/src/newt/classes/com/jogamp/newt/Window.java b/src/newt/classes/com/jogamp/newt/Window.java
index e43961e98..82f878a98 100644
--- a/src/newt/classes/com/jogamp/newt/Window.java
+++ b/src/newt/classes/com/jogamp/newt/Window.java
@@ -1029,8 +1029,9 @@ public interface Window extends NativeWindow, WindowClosingProtocol, ScalableSur
      * @param y dirty-region x-pos in pixel units
      * @param width dirty-region width in pixel units
      * @param height dirty-region height in pixel units
+     * @return true if window {@link #isNativeValid()}
      */
-    void windowRepaint(int x, int y, int width, int height);
+    boolean windowRepaint(int x, int y, int width, int height);
 
     /**
      * Enqueues a {@link com.jogamp.newt.event.NEWTEvent NEWT event}.
diff --git a/src/newt/classes/com/jogamp/newt/opengl/GLWindow.java b/src/newt/classes/com/jogamp/newt/opengl/GLWindow.java
index cbac22e26..09f5e1ebf 100644
--- a/src/newt/classes/com/jogamp/newt/opengl/GLWindow.java
+++ b/src/newt/classes/com/jogamp/newt/opengl/GLWindow.java
@@ -844,8 +844,8 @@ public class GLWindow extends GLAutoDrawableBase implements GLAutoDrawable, Wind
     // Window completion
     //
     @Override
-    public final void windowRepaint(final int x, final int y, final int width, final int height) {
-        window.windowRepaint(x, y, width, height);
+    public final boolean windowRepaint(final int x, final int y, final int width, final int height) {
+        return window.windowRepaint(x, y, width, height);
     }
 
     @Override