add stackabove test, that lets you move a client window just above a specified window in the stacking order

tests/stackabove.c

@@ -0,0 +1,73 @@
+/* -*- indent-tabs-mode: nil; tab-width: 4; c-basic-offset: 4; -*-
+
+   extentsrequest.c for the Openbox window manager
+   Copyright (c) 2003-2007   Dana Jansens
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 2 of the License, or
+   (at your option) any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   See the COPYING file for a copy of the GNU General Public License.
+*/
+
+/* Will find the frame for this window and stack itself right above it */
+#define GO_ABOVE 0x4c0003c
+
+#include <stdio.h>
+#include <unistd.h>
+#include <X11/Xlib.h>
+#include <X11/Xatom.h>
+
+int main () {
+  Display   *display;
+  Window     win, frame, a, p, *c;
+  unsigned int n;
+  XWindowChanges changes;
+  XEvent     report;
+  XEvent     msg;
+  int        x=10,y=10,h=100,w=400;
+
+  display = XOpenDisplay(NULL);
+
+  if (display == NULL) {
+    fprintf(stderr, "couldn't connect to X server :0\n");
+    return 0;
+  }
+
+  win = XCreateWindow(display, RootWindow(display, 0),
+                      x, y, w, h, 10, CopyFromParent, CopyFromParent,
+                      CopyFromParent, 0, NULL);
+  XSetWindowBackground(display,win,WhitePixel(display,0));
+
+  XMapWindow(display, win);
+  XFlush(display);
+
+  printf("requesting move in 10\n");
+  sleep(10);
+
+  frame = win;
+  while (XQueryTree(display, frame, &a, &p, &c, &n) && p != a)
+      frame = p;
+
+  changes.sibling = GO_ABOVE;
+  while (XQueryTree(display, changes.sibling, &a, &p, &c, &n) && p != a)
+      changes.sibling = p;
+
+  changes.stack_mode = Above;
+  XConfigureWindow(display, frame, CWSibling | CWStackMode, &changes);
+  XFlush(display);
+
+  printf("moved 0x%lx above 0x%lx\n", frame, changes.sibling);
+
+  while (1) {
+    XNextEvent(display, &report);
+  }
+
+  return 1;
+}