Fix drag-and-drop bugs on Lucid build

Also, optimize Fx_translate_coordinates to avoid excessive calls
to _XReply.

* lisp/x-dnd.el (x-dnd-get-drop-rectangle): Return empty drop
rectangle if posn-area.
* src/xfns.c (Fx_translate_coordinates): Accept arg
`require_child'.  If not set, allow optimizations based on
cached position data.
* src/xselect.c (x_handle_dnd_message): Use
x_translate_coordinates.
* src/xterm.c (x_translate_coordinates): Export function.
(x_handle_translate_coordinates): New function.
(handle_one_xevent): Fix coding style.
* src/xterm.h: Update prototypes.

1 files changed, 4 insertions, 0 deletions

diff --git a/src/xterm.h b/src/xterm.h
index 2967d105ea2..537cabc9577 100644
--- a/src/xterm.h
+++ b/src/xterm.h
@@ -1695,8 +1695,12 @@ extern void x_xr_apply_ext_clip (struct frame *, GC);
 extern void x_xr_reset_ext_clip (struct frame *);
 #endif
 
+extern void x_translate_coordinates (struct frame *, int, int, int *, int *);
 extern void x_translate_coordinates_to_root (struct frame *, int, int,
                                              int *, int *);
+extern Lisp_Object x_handle_translate_coordinates (struct frame *, Lisp_Object,
+                                                   int, int);
+
 extern Bool x_query_pointer (Display *, Window, Window *, Window *, int *,
                              int *, int *, int *, unsigned int *);