fix: cpu pegging when shpool attach stdin is null

libshpool/src/protocol.rs

@@ -257,7 +257,7 @@ impl Client {
                 loop {
                     let nread = stdin.read(&mut buf).context("reading stdin from user")?;
                     if nread == 0 {
-                        continue;
+                        return Ok(());
                     }
                     debug!("read {} bytes", nread);
 
@@ -371,12 +371,22 @@ impl Client {
             }
 
             match stdin_to_sock_h.join() {
-                Ok(v) => v?,
+                Ok(v) => {
+                    if let Err(e) = v {
+                        info!("stdin->sock finished with err: {}", e);
+                    }
+                }
                 Err(panic_err) => std::panic::resume_unwind(panic_err),
             }
             match sock_to_stdout_h.join() {
-                Ok(v) => v?,
-                Err(panic_err) => std::panic::resume_unwind(panic_err),
+                Ok(v) => {
+                    if let Err(e) = v {
+                        info!("sock->stdout finished with err: {}", e);
+                    }
+                }
+                Err(panic_err) => {
+                    std::panic::resume_unwind(panic_err);
+                }
             }
 
             Ok(exit_status.load(Ordering::Acquire))

shpool/tests/attach.rs

@@ -545,6 +545,7 @@ fn default_keybinding_detach() -> anyhow::Result<()> {
 
     a1.run_raw_cmd(vec![0, 17])?; // Ctrl-Space Ctrl-q
     let exit_status = a1.proc.wait()?;
+    dbg!(exit_status);
     assert!(exit_status.success());
 
     waiter.wait_event("daemon-bidi-stream-done")?;
@@ -1567,6 +1568,39 @@ fn version_mismatch_client_newer() -> anyhow::Result<()> {
     Ok(())
 }
 
+#[test]
+#[timeout(30000)]
+fn detaches_on_null_stdin() -> anyhow::Result<()> {
+    let mut daemon_proc = support::daemon::Proc::new("norc.toml", DaemonArgs::default())
+        .context("starting daemon proc")?;
+    let _attach_proc = daemon_proc
+        .attach("sh1", AttachArgs { null_stdin: true, ..Default::default() })
+        .context("starting attach proc")?;
+
+    // not really needed, just here to test the events system
+    daemon_proc.await_event("daemon-about-to-listen")?;
+
+    loop {
+        thread::sleep(time::Duration::from_millis(300));
+
+        let list_json_out = daemon_proc.list_json()?;
+        let list_str = String::from_utf8_lossy(&list_json_out.stdout);
+        eprintln!("LIST OUTPUT: '{}'", list_str);
+
+        let list_blob: serde_json::Value = serde_json::from_str(&list_str)?;
+
+        if list_blob["sessions"].as_array().unwrap().is_empty() {
+            continue;
+        }
+        assert_eq!(list_blob["sessions"][0]["name"].as_str().unwrap(), "sh1");
+        if list_blob["sessions"][0]["status"].as_str().unwrap() != "Disconnected" {
+            continue;
+        }
+
+        return Ok(());
+    }
+}
+
 #[ignore] // TODO: re-enable, this test if flaky
 #[test]
 fn up_arrow_no_crash() -> anyhow::Result<()> {

shpool/tests/support/daemon.rs

@@ -50,6 +50,7 @@ pub struct AttachArgs {
     pub ttl: Option<time::Duration>,
     pub cmd: Option<String>,
     pub dir: Option<String>,
+    pub null_stdin: bool,
 }
 
 pub struct HooksRecorder {
@@ -287,7 +288,7 @@ impl Proc {
         let mut cmd = Command::new(shpool_bin()?);
         cmd.stdout(Stdio::piped())
             .stderr(Stdio::piped())
-            .stdin(Stdio::piped())
+            .stdin(if args.null_stdin { Stdio::null() } else { Stdio::piped() })
             .arg("--config-file")
             .arg(if let Some(config_file) = args.config {
                 testdata_file(config_file)