From 67d54ef3d53e5257e465ec556177ea569100263e Mon Sep 17 00:00:00 2001
From: Aleksei Bavshin <alebastr89@gmail.com>
Date: Sat, 24 Oct 2020 22:56:24 -0700
Subject: [PATCH] fix(wlr/taskbar): do not bind to unsupported protocol
 versions

It's not allowed to bind to a higher version of a wayland protocol than
supported by the client. Binding wlr-foreign-toplevel-manager-v1 v3 to
a generated code for v2 causes errors in libwayland due to a missing
handler for `zwlr_foreign_toplevel_handle_v1.parent` event.
---
 src/client.cpp              | 2 ++
 src/modules/wlr/taskbar.cpp | 5 ++++-
 2 files changed, 6 insertions(+), 1 deletion(-)

diff --git a/src/client.cpp b/src/client.cpp
index 70cc22cf..9dd93d81 100644
--- a/src/client.cpp
+++ b/src/client.cpp
@@ -32,6 +32,8 @@ void waybar::Client::handleGlobal(void *data, struct wl_registry *registry, uint
                                   const char *interface, uint32_t version) {
   auto client = static_cast<Client *>(data);
   if (strcmp(interface, zwlr_layer_shell_v1_interface.name) == 0) {
+    // limit version to a highest supported by the client protocol file
+    version = std::min<uint32_t>(version, zwlr_layer_shell_v1_interface.version);
     client->layer_shell = static_cast<struct zwlr_layer_shell_v1 *>(
         wl_registry_bind(registry, name, &zwlr_layer_shell_v1_interface, version));
   } else if (strcmp(interface, zxdg_output_manager_v1_interface.name) == 0 &&
diff --git a/src/modules/wlr/taskbar.cpp b/src/modules/wlr/taskbar.cpp
index 45915dc6..8d6fa9b4 100644
--- a/src/modules/wlr/taskbar.cpp
+++ b/src/modules/wlr/taskbar.cpp
@@ -653,9 +653,11 @@ void Taskbar::register_manager(struct wl_registry *registry, uint32_t name, uint
         spdlog::warn("Register foreign toplevel manager again although already existing!");
         return;
     }
-    if (version != 2) {
+    if (version < ZWLR_FOREIGN_TOPLEVEL_HANDLE_V1_STATE_FULLSCREEN_SINCE_VERSION) {
         spdlog::warn("Using different foreign toplevel manager protocol version: {}", version);
     }
+    // limit version to a highest supported by the client protocol file
+    version = std::min<uint32_t>(version, zwlr_foreign_toplevel_manager_v1_interface.version);
 
     manager_ = static_cast<struct zwlr_foreign_toplevel_manager_v1 *>(wl_registry_bind(registry, name,
             &zwlr_foreign_toplevel_manager_v1_interface, version));
@@ -672,6 +674,7 @@ void Taskbar::register_seat(struct wl_registry *registry, uint32_t name, uint32_
         spdlog::warn("Register seat again although already existing!");
         return;
     }
+    version = std::min<uint32_t>(version, wl_seat_interface.version);
 
     seat_ = static_cast<wl_seat*>(wl_registry_bind(registry, name, &wl_seat_interface, version));
 }