diff -Nru sway-1.5.1/debian/changelog sway-1.5.1/debian/changelog
--- sway-1.5.1/debian/changelog	2021-02-14 12:36:51.000000000 +0100
+++ sway-1.5.1/debian/changelog	2021-06-14 21:24:42.000000000 +0200
@@ -1,3 +1,11 @@
+sway (1.5.1-2ubuntu1) UNRELEASED; urgency=medium
+
+  * debian/patches/9999-backport-subsurface-parent-fix-lp-1924800.patch:
+    Backport fix for subsurface parent bug that causes firefox popups to
+    flicker
+
+ -- Wouter Horré <wouter@horre.be>  Mon, 14 Jun 2021 21:24:42 +0200
+
 sway (1.5.1-2) unstable; urgency=medium
 
   * Update dependency on wlroots (0.12 or higher)
diff -Nru sway-1.5.1/debian/patches/9999-backport-subsurface-parent-fix-lp-1924800.patch sway-1.5.1/debian/patches/9999-backport-subsurface-parent-fix-lp-1924800.patch
--- sway-1.5.1/debian/patches/9999-backport-subsurface-parent-fix-lp-1924800.patch	1970-01-01 01:00:00.000000000 +0100
+++ sway-1.5.1/debian/patches/9999-backport-subsurface-parent-fix-lp-1924800.patch	2021-06-14 21:24:42.000000000 +0200
@@ -0,0 +1,131 @@
+## Description: Backported subsurface parent fixes
+## Origin/Author: https://github.com/swaywm/sway/pull/6283
+## Bug: https://github.com/swaywm/sway/issues/6038
+Index: sway-1.5.1/.builds/alpine.yml
+===================================================================
+--- sway-1.5.1.orig/.builds/alpine.yml
++++ sway-1.5.1/.builds/alpine.yml
+@@ -16,10 +16,10 @@ packages:
+   - wayland-dev
+   - wayland-protocols
+   - xcb-util-image-dev
+-  - xorg-server-xwayland
++  - xwayland
+ sources:
+   - https://github.com/swaywm/sway
+-  - https://github.com/swaywm/wlroots
++  - https://github.com/swaywm/wlroots#0.12.0
+ tasks:
+   - wlroots: |
+       cd wlroots
+Index: sway-1.5.1/.builds/archlinux.yml
+===================================================================
+--- sway-1.5.1.orig/.builds/archlinux.yml
++++ sway-1.5.1/.builds/archlinux.yml
+@@ -3,6 +3,7 @@ packages:
+   - cairo
+   - gdk-pixbuf2
+   - json-c
++  - libegl
+   - libinput
+   - libxcb
+   - libxkbcommon
+@@ -12,10 +13,10 @@ packages:
+   - wayland
+   - wayland-protocols
+   - xcb-util-image
+-  - xorg-server-xwayland
++  - xorg-xwayland
+ sources:
+   - https://github.com/swaywm/sway
+-  - https://github.com/swaywm/wlroots
++  - https://github.com/swaywm/wlroots#0.12.0
+ tasks:
+   - wlroots: |
+       cd wlroots
+Index: sway-1.5.1/.builds/freebsd.yml
+===================================================================
+--- sway-1.5.1.orig/.builds/freebsd.yml
++++ sway-1.5.1/.builds/freebsd.yml
+@@ -24,7 +24,7 @@ packages:
+ - x11/xcb-util-wm
+ sources:
+ - https://github.com/swaywm/sway
+-- https://github.com/swaywm/wlroots
++- https://github.com/swaywm/wlroots#0.12.0
+ tasks:
+ - setup: |
+     cd sway
+Index: sway-1.5.1/sway/tree/view.c
+===================================================================
+--- sway-1.5.1.orig/sway/tree/view.c
++++ sway-1.5.1/sway/tree/view.c
+@@ -464,6 +464,9 @@ static void view_subsurface_create(struc
+ static void view_init_subsurfaces(struct sway_view *view,
+ 	struct wlr_surface *surface);
+ 
++static void view_child_init_subsurfaces(struct sway_view_child *view_child,
++	struct wlr_surface *surface);
++
+ static void view_handle_surface_new_subsurface(struct wl_listener *listener,
+ 		void *data) {
+ 	struct sway_view *view =
+@@ -906,8 +909,18 @@ static void view_child_subsurface_create
+ 	view_child_damage(&subsurface->child, true);
+ }
+ 
++static bool view_child_is_mapped(struct sway_view_child *child) {
++	while (child) {
++		if (!child->mapped) {
++			return false;
++		}
++		child = child->parent;
++	}
++	return true;
++}
++
+ static void view_child_damage(struct sway_view_child *child, bool whole) {
+-	if (!child || !child->mapped || !child->view || !child->view->container) {
++	if (!child || !view_child_is_mapped(child) || !child->view || !child->view->container) {
+ 		return;
+ 	}
+ 	int sx, sy;
+@@ -947,6 +960,14 @@ static void view_init_subsurfaces(struct
+ 	}
+ }
+ 
++static void view_child_init_subsurfaces(struct sway_view_child *view_child,
++		struct wlr_surface *surface) {
++	struct wlr_subsurface *subsurface;
++	wl_list_for_each(subsurface, &surface->subsurfaces, parent_link) {
++		view_child_subsurface_create(view_child, subsurface);
++	}
++}
++
+ static void view_child_handle_surface_map(struct wl_listener *listener,
+ 		void *data) {
+ 	struct sway_view_child *child =
+@@ -1002,11 +1023,11 @@ void view_child_init(struct sway_view_ch
+ 		wlr_surface_send_enter(child->surface, workspace->output->wlr_output);
+ 	}
+ 
+-	view_init_subsurfaces(child->view, surface);
++	view_child_init_subsurfaces(child, surface);
+ }
+ 
+ void view_child_destroy(struct sway_view_child *child) {
+-	if (child->mapped && child->view->container != NULL) {
++	if (view_child_is_mapped(child) && child->view->container != NULL) {
+ 		view_child_damage(child, true);
+ 	}
+ 
+@@ -1019,6 +1040,9 @@ void view_child_destroy(struct sway_view
+ 	wl_list_for_each_safe(subchild, tmpchild, &child->children, link) {
+ 		wl_list_remove(&subchild->link);
+ 		subchild->parent = NULL;
++		// The subchild lost its parent link, so it cannot see that the parent
++		// is unmapped. Unmap it directly.
++		subchild->mapped = false;
+ 	}
+ 
+ 	wl_list_remove(&child->surface_commit.link);
diff -Nru sway-1.5.1/debian/patches/series sway-1.5.1/debian/patches/series
--- sway-1.5.1/debian/patches/series	2021-02-14 12:36:51.000000000 +0100
+++ sway-1.5.1/debian/patches/series	2021-06-14 21:22:45.000000000 +0200
@@ -1,2 +1,3 @@
 0001-Install-zsh-completions-into-the-correct-directory.patch
 0002-Modify-default-configuration-for-Debian.patch
+9999-backport-subsurface-parent-fix-lp-1924800.patch