x11: iterate only visuals from the matching screen

src/changelog/unreleased.md

@@ -53,3 +53,4 @@ changelog entry.
 - On macOS, fix crash when calling `drag_window()` without a left click present.
 - On X11, key events forward to IME anyway, even when it's disabled.
 - On Windows, make `ControlFlow::WaitUntil` work more precisely using `CREATE_WAITABLE_TIMER_HIGH_RESOLUTION`.
+- On X11, creating windows on screen that is not the first one (e.g. `DISPLAY=:0.1`) works again.

src/platform_impl/linux/x11/window.rs

@@ -212,13 +212,18 @@ impl UnownedWindow {
             None => xconn.default_screen_index() as c_int,
         };
 
-        // An iterator over all of the visuals combined with their depths.
-        let mut all_visuals = xconn
-            .xcb_connection()
-            .setup()
-            .roots
+        let screen = {
+            let screen_id_usize = usize::try_from(screen_id)
+                .map_err(|_| os_error!(OsError::Misc("screen id must be non-negative")))?;
+            xconn.xcb_connection().setup().roots.get(screen_id_usize).ok_or(os_error!(
+                OsError::Misc("requested screen id not present in server's response")
+            ))?
+        };
+
+        // An iterator over the visuals matching screen id combined with their depths.
+        let mut all_visuals = screen
+            .allowed_depths
             .iter()
-            .flat_map(|root| &root.allowed_depths)
             .flat_map(|depth| depth.visuals.iter().map(move |visual| (visual, depth.depth)));
 
         // creating