* macterm.c (XTread_socket): Checks for valid, visible window

	before sending a scroll-wheel event.

2 files changed, 12 insertions, 0 deletions

diff --git a/src/ChangeLog b/src/ChangeLog
index 3f0eb5db6a..c110217d1e 100644
--- a/src/ChangeLog
+++ b/src/ChangeLog
@@ -1,3 +1,8 @@
+2003-01-20  Steven Tamm  <[email protected]>
+
+	* macterm.c (XTread_socket): Checks for valid, visible window
+	before sending a scroll-wheel event.
+
 2003-01-20  Richard M. Stallman  <[email protected]>
 
 	* xdisp.c (redisplay_window): If mini window's buffer is not
diff --git a/src/macterm.c b/src/macterm.c
index cae4172854..e969a4b6dc 100644
--- a/src/macterm.c
+++ b/src/macterm.c
@@ -12644,6 +12644,13 @@ XTread_socket (int sd, struct input_event *bufp, int numchars, int expected)
 		Point point;
 		WindowPtr window_ptr = FrontNonFloatingWindow ();
 		struct mac_output *mwp = (mac_output *) GetWRefCon (window_ptr);
+		if (!IsValidWindowPtr (window_ptr))
+		  {
+		    SysBeep(1);
+		    UNBLOCK_INPUT;
+		    return 0;
+		  }
+
 		GetEventParameter(eventRef, kEventParamMouseWheelDelta,
 				  typeSInt32, NULL, sizeof (SInt32),
 				  NULL, &delta);