fix: occasional garbage on attaching through slow connections (#5320)

* fix: occasional garbage on attaching through slow connections

* rustfmt

* add PR

1 files changed, 102 insertions, 0 deletions

diff --git a/zellij-integration-tests/tests/startup_host_query.rs b/zellij-integration-tests/tests/startup_host_query.rs
new file mode 100644
index 00000000..514df24f
--- /dev/null
+++ b/zellij-integration-tests/tests/startup_host_query.rs
@@ -0,0 +1,102 @@
+#![cfg(unix)]
+
+use std::thread::sleep;
+use std::time::Duration;
+
+use zellij_integration_tests::{
+    claim_first_terminal_and_wait_for_prompt, keys, start_zellij, TestSession,
+};
+
+const IDLE_BEYOND_SHORT_FLUSH: Duration = Duration::from_millis(150);
+
+fn lock_interface(zellij: &TestSession) {
+    zellij.send_stdin(&keys::ctrl('g'));
+    zellij.wait_until("interface locked", |grid_snapshot| {
+        grid_snapshot.contains("LOCK") && !grid_snapshot.contains("PANE")
+    });
+}
+
+fn unlock_interface(zellij: &TestSession) {
+    zellij.send_stdin(&keys::ctrl('g'));
+    zellij.wait_until("interface unlocked", |grid_snapshot| {
+        grid_snapshot.contains("PANE")
+    });
+}
+
+#[test]
+fn fragmented_attach_reply_burst_does_not_leak_into_focused_pane() {
+    let mut zellij = start_zellij();
+    let terminal = claim_first_terminal_and_wait_for_prompt(&zellij);
+    lock_interface(&zellij);
+
+    zellij.send_stdin(b"\x1b]4;1;rgb:abcd");
+    sleep(IDLE_BEYOND_SHORT_FLUSH);
+    zellij.send_stdin(b"/ef01/2345\x1b\\");
+
+    zellij.send_stdin(b"Z");
+    let stdin = terminal.wait_for_stdin("sentinel keystroke reached the pane", |stdin_bytes| {
+        stdin_bytes.contains(&b'Z')
+    });
+
+    assert!(
+        !stdin.windows(4).any(|window| window == b"rgb:"),
+        "host reply bytes leaked into the pane: {:?}",
+        stdin
+    );
+    assert!(
+        !stdin.contains(&b'/'),
+        "host reply payload leaked into the pane: {:?}",
+        stdin
+    );
+    assert!(
+        !stdin.contains(&b';'),
+        "host reply payload leaked into the pane: {:?}",
+        stdin
+    );
+
+    unlock_interface(&zellij);
+    zellij.quit();
+}
+
+#[test]
+fn fragmented_function_key_arrives_intact() {
+    let mut zellij = start_zellij();
+    let terminal = claim_first_terminal_and_wait_for_prompt(&zellij);
+    lock_interface(&zellij);
+
+    zellij.send_stdin(b"\x1b[1;5");
+    sleep(IDLE_BEYOND_SHORT_FLUSH);
+    zellij.send_stdin(b"C");
+
+    terminal.wait_for_stdin("ctrl-right reached the pane intact", |stdin_bytes| {
+        stdin_bytes.windows(6).any(|window| window == b"\x1b[1;5C")
+    });
+
+    unlock_interface(&zellij);
+    zellij.quit();
+}
+
+#[test]
+fn normal_typing_is_not_delayed_or_duplicated() {
+    let mut zellij = start_zellij();
+    let terminal = claim_first_terminal_and_wait_for_prompt(&zellij);
+    lock_interface(&zellij);
+
+    zellij.send_stdin(b"hello");
+    let stdin = terminal.wait_for_stdin("typed keys reached the pane", |stdin_bytes| {
+        stdin_bytes.windows(5).any(|window| window == b"hello")
+    });
+
+    let occurrences = stdin
+        .windows(5)
+        .filter(|window| *window == b"hello")
+        .count();
+    assert_eq!(
+        occurrences, 1,
+        "typed keys must reach the pane exactly once: {:?}",
+        stdin
+    );
+
+    unlock_interface(&zellij);
+    zellij.quit();
+}