mouse fix for nt tty

No wonder we've had complaints about the mouse lately.
The port was responding to mouse movements that didn't
even involve a button click.

doc/fixes34.1

@@ -61,6 +61,7 @@ win32: win32 build no longer defines MICRO
 win32: allow error save files to be generated
 win32gui: make error() work; it was essentially non-operative in 3.4.0
 win32tty: honour the use_inverse option and default to ATR_BOLD if disabled
+win32tty: respond only to mouse clicks not mouse movement
 X11: restore support for non-square tiles when USE_XPM is defined
 Gnome: add support for non-square tiles
 tty: remove #define DEBUG that forced debug behavior in production builds

sys/winnt/nttty.c

@@ -432,8 +432,10 @@ int *x, *y, *mod;
 		     (ch || (iskeypad(scan)) || altseq)) {
 		     	*mod = 0;
 			return process_keystroke(&ir, &valid);
-		} else if ((ir.EventType == MOUSE_EVENT &&
-		  (ir.Event.MouseEvent.dwButtonState & MOUSEMASK))) {
+		} else if (
+		  (ir.EventType == MOUSE_EVENT &&
+		   (ir.Event.MouseEvent.dwEventFlags == 0) &&
+		   (ir.Event.MouseEvent.dwButtonState & MOUSEMASK))) {
 		  	*x = ir.Event.MouseEvent.dwMousePosition.X + 1;
 		  	*y = ir.Event.MouseEvent.dwMousePosition.Y - 1;