From f8507a681f838d13874cb541f60249e069f5d52f Mon Sep 17 00:00:00 2001
From: Abanoub <abanoubsameh@protonmail.com>
Date: Wed, 21 Jun 2023 18:07:43 +0300
Subject: [PATCH] Fix the bug with the movestack patch, which crashes dwl if
 the current tag has no clients

---
 config.def.h |  2 ++
 dwl.c        | 35 +++++++++++++++++++++++++++++++++++
 2 files changed, 37 insertions(+)

diff --git a/config.def.h b/config.def.h
index 447ba0051..ffd0af28c 100644
--- a/config.def.h
+++ b/config.def.h
@@ -113,6 +113,8 @@ static const Key keys[] = {
 	{ MODKEY|WLR_MODIFIER_SHIFT, XKB_KEY_Return,     spawn,          {.v = termcmd} },
 	{ MODKEY,                    XKB_KEY_j,          focusstack,     {.i = +1} },
 	{ MODKEY,                    XKB_KEY_k,          focusstack,     {.i = -1} },
+	{ MODKEY|WLR_MODIFIER_SHIFT, XKB_KEY_J,          movestack,      {.i = +1} },
+	{ MODKEY|WLR_MODIFIER_SHIFT, XKB_KEY_K,          movestack,      {.i = -1} },
 	{ MODKEY,                    XKB_KEY_i,          incnmaster,     {.i = +1} },
 	{ MODKEY,                    XKB_KEY_d,          incnmaster,     {.i = -1} },
 	{ MODKEY,                    XKB_KEY_h,          setmfact,       {.f = -0.05} },
diff --git a/dwl.c b/dwl.c
index da3a51613..efbe0c016 100644
--- a/dwl.c
+++ b/dwl.c
@@ -272,6 +272,7 @@ static void maplayersurfacenotify(struct wl_listener *listener, void *data);
 static void mapnotify(struct wl_listener *listener, void *data);
 static void maximizenotify(struct wl_listener *listener, void *data);
 static void monocle(Monitor *m);
+static void movestack(const Arg *arg);
 static void motionabsolute(struct wl_listener *listener, void *data);
 static void motionnotify(uint32_t time);
 static void motionrelative(struct wl_listener *listener, void *data);
@@ -1615,6 +1616,40 @@ monocle(Monitor *m)
 		wlr_scene_node_raise_to_top(&c->scene->node);
 }
 
+void
+movestack(const Arg *arg)
+{
+    Client *c, *sel = focustop(selmon);
+
+    if (!sel) {
+        return;
+    }
+
+    if (wl_list_length(&clients) <= 1) {
+        return;
+    }
+
+    if (arg->i > 0) {
+        wl_list_for_each(c, &sel->link, link) {
+            if (VISIBLEON(c, selmon) || &c->link == &clients) {
+                break; /* found it */
+            }
+        }
+    } else {
+        wl_list_for_each_reverse(c, &sel->link, link) {
+            if (VISIBLEON(c, selmon) || &c->link == &clients) {
+                break; /* found it */
+            }
+        }
+        /* backup one client */
+        c = wl_container_of(c->link.prev, c, link);
+    }
+
+    wl_list_remove(&sel->link);
+    wl_list_insert(&c->link, &sel->link);
+    arrange(selmon);
+}
+
 void
 motionabsolute(struct wl_listener *listener, void *data)
 {