fix(tray): Support clients with different depths

XCB_BACK_PIXMAP_PARENT_RELATIVE requires that the client has the same
depth as the tray window.

There was an issue with dropbox having a depth of 32 and the tray window
having a depth of 24 that caused the configuration of the icon to fail.
It would then be displayed outside of the bar because the catch block
was not hit (different exception).

We now just don't configure XCB_CW_BACK_PIXMAP. This seems to work and
is also what stalonetray does.

This does not fix the issue with dropbox having an arbitrary background.

Fixes polybar#1679
Fixes polybar#2430

CHANGELOG.md

@@ -11,6 +11,8 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 ## [Unreleased]
 ### Build
 - Support building documentation on sphinx 4.0 ([`#2424`](https://github.com/polybar/polybar/issues/2424))
+### Fixed
+- Tray icons sometimes appears outside of bar ([`#2430`](https://github.com/polybar/polybar/issues/2430), [`#1679`](https://github.com/polybar/polybar/issues/1679))
 
 ## [3.5.5] - 2021-03-01
 ### Build

src/x11/tray_manager.cpp

@@ -726,26 +726,23 @@ void tray_manager::track_selection_owner(xcb_window_t owner) {
  * Process client docking request
  */
 void tray_manager::process_docking_request(xcb_window_t win) {
-  m_log.info("Processing docking request from %s", m_connection.id(win));
+  m_log.info("Processing docking request from '%s' (%s)", ewmh_util::get_wm_name(win), m_connection.id(win));
 
   m_clients.emplace_back(factory_util::shared<tray_client>(m_connection, win, m_opts.width, m_opts.height));
   auto& client = m_clients.back();
 
   try {
     m_log.trace("tray: Get client _XEMBED_INFO");
     xembed::query(m_connection, win, client->xembed());
-  } catch (const application_error& err) {
-    m_log.err(err.what());
-  } catch (const xpp::x::error::window& err) {
+  } catch (const std::exception& err) {
     m_log.err("Failed to query _XEMBED_INFO, removing client... (%s)", err.what());
     remove_client(win, true);
     return;
   }
 
   try {
-    const unsigned int mask{XCB_CW_BACK_PIXMAP | XCB_CW_EVENT_MASK};
-    const unsigned int values[]{
-        XCB_BACK_PIXMAP_PARENT_RELATIVE, XCB_EVENT_MASK_PROPERTY_CHANGE | XCB_EVENT_MASK_STRUCTURE_NOTIFY};
+    const unsigned int mask = XCB_CW_EVENT_MASK;
+    const unsigned int values[]{XCB_EVENT_MASK_PROPERTY_CHANGE | XCB_EVENT_MASK_STRUCTURE_NOTIFY};
 
     m_log.trace("tray: Update client window");
     m_connection.change_window_attributes_checked(client->window(), mask, values);
@@ -767,8 +764,9 @@ void tray_manager::process_docking_request(xcb_window_t win) {
       m_log.trace("tray: Map client");
       m_connection.map_window_checked(client->window());
     }
-  } catch (const xpp::x::error::window& err) {
-    m_log.err("Failed to setup tray client, removing... (%s)", err.what());
+
+  } catch (const std::exception& err) {
+    m_log.err("Failed to setup tray client removing... (%s)", err.what());
     remove_client(win, false);
   }
 }