desktop-shell: set the current size in the first 'resizing' configure event

Weston has sent the first 'resizing' configure event with width=height=0.
But resizing to that size doesn't make sense.
Instead, we now send the current width and height of the surface at the beginning
of resizing.

Signed-off-by: Ryo Munakata <ryomnktml@gmail.com>
diff --git a/desktop-shell/shell.c b/desktop-shell/shell.c
index bcde3fb..c05a5c7 100644
--- a/desktop-shell/shell.c
+++ b/desktop-shell/shell.c
@@ -491,6 +491,9 @@
 
 		width = area.width;
 		height = area.height;
+	} else if (shsurf->resize_edges) {
+		width = shsurf->geometry.width;
+		height = shsurf->geometry.height;
 	} else {
 		width = 0;
 		height = 0;