If the cursor moves from one register cell to another, refresh the register headers.

If trading accounts are on and the transaction is expanded then the headers
depend on the type of split the cursor is in.

src/register/register-gnome/gnucash-header.c

@@ -222,7 +222,7 @@ gnc_header_draw (GnomeCanvasItem *item, GdkDrawable *drawable,
 }
 
 
-static void
+void
 gnc_header_request_redraw (GncHeader *header)
 {
     GnomeCanvas *canvas = GNOME_CANVAS_ITEM(header)->canvas;

src/register/register-gnome/gnucash-header.h

@@ -64,6 +64,7 @@ typedef struct
 
 GtkWidget *gnc_header_new (GnucashSheet *sheet);
 void gnc_header_reconfigure (GncHeader *header);
+void gnc_header_request_redraw (GncHeader *header);
 
 void gnc_header_set_header_rows (GncHeader *header,
                                  int num_phys_rows);

src/register/register-gnome/gnucash-sheet.c

@@ -349,6 +349,10 @@ gnucash_sheet_cursor_move (GnucashSheet *sheet, VirtualLocation virt_loc)
 
     changed_cells = !virt_loc_equal (virt_loc, old_virt_loc);
     
+    /* If we've changed cells, redraw the headers */
+    if (changed_cells)
+        gnc_header_request_redraw (GNC_HEADER(sheet->header_item));
+
     /* Now turn on the editing controls. */
     gnucash_sheet_activate_cursor_cell (sheet, changed_cells);