T46: Ely peeks over the main window's top edge from behind it, as the owner asked after the 0.1.3 film: her head and fingers from the icon's paths in a transparent window of her own, kept on the edge as each platform allows, macOS's child window, Windows' owned popup, X11's popup moved and stacked above the frame, Wayland's anchored popup; ten faces follow the most pressing of the sessions' marks, with hops, a shake and a rise; a press winks; Settings, Terminal, Ely turns her off

src/testx11.rs

@@ -0,0 +1,37 @@
+//! Xvfb for the X11 tests.
+
+use std::{
+    io::{BufRead, BufReader},
+    process::{Child, Command, Stdio},
+};
+
+/// An X server of the test's own, gone with it.
+pub struct Xvfb {
+    child: Child,
+    pub display: String,
+}
+
+impl Xvfb {
+    pub fn start() -> Self {
+        let mut child = Command::new("Xvfb")
+            .args(["-displayfd", "1", "-nolisten", "tcp"])
+            .stdout(Stdio::piped())
+            .spawn()
+            .expect("Xvfb starts: the X11 tests need it");
+        let mut number = String::new();
+        let stdout = child.stdout.take().expect("Xvfb's stdout");
+        BufReader::new(stdout)
+            .read_line(&mut number)
+            .expect("Xvfb names its display");
+        let display = format!(":{}", number.trim());
+        Self { child, display }
+    }
+}
+
+impl Drop for Xvfb {
+    fn drop(&mut self) {
+        if let Err(error) = self.child.kill().and_then(|()| self.child.wait().map(drop)) {
+            eprintln!("Xvfb {} did not stop: {error}", self.display);
+        }
+    }
+}