Dont include dock clients in ewmh lists

http://standards.freedesktop.org/wm-spec/latest/ar01s03.html#idm140251368149456

The _NET_CLIENT_LIST property of the root window:

> These arrays contain all X Windows managed by the Window Manager.

Dock clients are not managed windows, so they should not be included in
_NET_CLIENT_LIST or _NET_CLIENT_LIST_STACKING.

include/con.h

@@ -37,6 +37,12 @@ void con_focus(Con *con);
  */
 bool con_is_leaf(Con *con);
 
+/**
+ * Returns true when this con is a leaf node with a managed X11 window (e.g.,
+ * excluding dock containers)
+ */
+bool con_has_managed_window(Con *con);
+
 /*
  * Returns true if a container should be considered split.
  *

src/con.c

@@ -241,6 +241,17 @@ bool con_is_leaf(Con *con) {
     return TAILQ_EMPTY(&(con->nodes_head));
 }
 
+/*
+ * Returns true when this con is a leaf node with a managed X11 window (e.g.,
+ * excluding dock containers)
+ */
+bool con_has_managed_window(Con *con) {
+    return (con != NULL
+            && con->window != NULL
+            && con->window->id != XCB_WINDOW_NONE
+            && con_get_workspace(con) != NULL);
+}
+
 /**
  * Returns true if this node has regular or floating children.
  *

src/x.c

@@ -908,7 +908,7 @@ void x_push_changes(Con *con) {
      * stack afterwards */
     int cnt = 0;
     CIRCLEQ_FOREACH_REVERSE(state, &state_head, state)
-        if (state->con && state->con->window)
+        if (con_has_managed_window(state->con))
             cnt++;
 
     /* The bottom-to-top window stack of all windows which are managed by i3.
@@ -925,7 +925,7 @@ void x_push_changes(Con *con) {
 
     /* X11 correctly represents the stack if we push it from bottom to top */
     CIRCLEQ_FOREACH_REVERSE(state, &state_head, state) {
-        if (state->con && state->con->window)
+        if (con_has_managed_window(state->con))
             memcpy(walk++, &(state->con->window->id), sizeof(xcb_window_t));
 
         //DLOG("stack: 0x%08x\n", state->id);
@@ -956,7 +956,7 @@ void x_push_changes(Con *con) {
 
         /* reorder by initial mapping */
         TAILQ_FOREACH(state, &initial_mapping_head, initial_mapping_order) {
-            if (state->con && state->con->window)
+            if (con_has_managed_window(state->con))
                 *walk++ = state->con->window->id;
         }
 

testcases/t/223-net-client-list.t

@@ -96,4 +96,13 @@ wait_for_unmap($win3);
 @clients = get_client_list;
 is(@clients, 0, 'Removed unmapped client from list (0)');
 
+# Dock clients should not be included in this list
+
+my $dock_win = open_window({
+        window_type => $x->atom(name => '_NET_WM_WINDOW_TYPE_DOCK'),
+    });
+
+@clients = get_client_list;
+is(@clients, 0, 'Dock clients are not included in the list');
+
 done_testing;