applied Andreas Amanns' netwm_client_list patch, but with some indentation fixes

dwm.c

@@ -60,7 +60,7 @@ enum { CurNormal, CurResize, CurMove, CurLast };        /* cursor */
 enum { ColBorder, ColFG, ColBG, ColLast };              /* color */
 enum { NetSupported, NetWMName, NetWMState,
        NetWMFullscreen, NetActiveWindow, NetWMWindowType,
-       NetWMWindowTypeDialog, NetLast };     /* EWMH atoms */
+       NetWMWindowTypeDialog, NetClientList, NetLast };     /* EWMH atoms */
 enum { WMProtocols, WMDelete, WMState, WMTakeFocus, WMLast }; /* default atoms */
 enum { ClkTagBar, ClkLtSymbol, ClkStatusText, ClkWinTitle,
        ClkClientWin, ClkRootWin, ClkLast };             /* clicks */
@@ -238,6 +238,7 @@ static void unmapnotify(XEvent *e);
 static Bool updategeom(void);
 static void updatebarpos(Monitor *m);
 static void updatebars(void);
+static void updateclientlist(void);
 static void updatenumlockmask(void);
 static void updatesizehints(Client *c);
 static void updatestatus(void);
@@ -1160,6 +1161,8 @@ manage(Window w, XWindowAttributes *wa) {
 		XRaiseWindow(dpy, c->win);
 	attach(c);
 	attachstack(c);
+	XChangeProperty(dpy, root, netatom[NetClientList], XA_WINDOW, 32, PropModeAppend,
+	                (unsigned char *) &(c->win), 1);
 	XMoveResizeWindow(dpy, c->win, c->x + 2 * sw, c->y, c->w, c->h); /* some windows require this */
 	setclientstate(c, NormalState);
 	if (c->mon == selmon)
@@ -1621,6 +1624,7 @@ setup(void) {
 	netatom[NetWMFullscreen] = XInternAtom(dpy, "_NET_WM_STATE_FULLSCREEN", False);
 	netatom[NetWMWindowType] = XInternAtom(dpy, "_NET_WM_WINDOW_TYPE", False);
 	netatom[NetWMWindowTypeDialog] = XInternAtom(dpy, "_NET_WM_WINDOW_TYPE_DIALOG", False);
+	netatom[NetClientList] = XInternAtom(dpy, "_NET_CLIENT_LIST", False);
 	/* init cursors */
 	cursor[CurNormal] = XCreateFontCursor(dpy, XC_left_ptr);
 	cursor[CurResize] = XCreateFontCursor(dpy, XC_sizing);
@@ -1643,6 +1647,7 @@ setup(void) {
 	/* EWMH support per view */
 	XChangeProperty(dpy, root, netatom[NetSupported], XA_ATOM, 32,
 			PropModeReplace, (unsigned char *) netatom, NetLast);
+	XDeleteProperty(dpy, root, netatom[NetClientList]);
 	/* select for events */
 	wa.cursor = cursor[CurNormal];
 	wa.event_mask = SubstructureRedirectMask|SubstructureNotifyMask|ButtonPressMask|PointerMotionMask
@@ -1820,6 +1825,7 @@ unmanage(Client *c, Bool destroyed) {
 	}
 	free(c);
 	focus(NULL);
+	updateclientlist();
 	arrange(m);
 }
 
@@ -1868,6 +1874,19 @@ updatebarpos(Monitor *m) {
 		m->by = -bh;
 }
 
+void
+updateclientlist() {
+	Client *c;
+	Monitor *m;
+
+	XDeleteProperty(dpy, root, netatom[NetClientList]);
+	for(m = mons; m; m = m->next)
+		for(c = m->clients; c; c = c->next)
+			XChangeProperty(dpy, root, netatom[NetClientList],
+			                XA_WINDOW, 32, PropModeAppend,
+			                (unsigned char *) &(c->win), 1);
+}
+
 Bool
 updategeom(void) {
 	Bool dirty = False;