Bump version to 1.0.0-rc12

Cargo.lock

@@ -436,7 +436,7 @@ dependencies = [
 
 [[package]]
 name = "dosh"
-version = "1.0.0-rc8"
+version = "1.0.0-rc12"
 dependencies = [
  "anyhow",
  "base64",

Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "dosh"
-version = "1.0.0-rc8"
+version = "1.0.0-rc12"
 edition = "2024"
 license = "MIT"
 

src/bin/dosh-client.rs

@@ -2498,11 +2498,15 @@ fn download_file(
         0
     };
     let mut file = if offset > 0 {
-        fs::OpenOptions::new()
+        let file = fs::OpenOptions::new()
             .read(true)
+            .write(true)
             .append(true)
             .open(local)
-            .with_context(|| format!("open {}", local.display()))?
+            .with_context(|| format!("open {}", local.display()))?;
+        file.set_len(offset)
+            .with_context(|| format!("truncate {}", local.display()))?;
+        file
     } else {
         fs::OpenOptions::new()
             .create(true)
@@ -5018,13 +5022,17 @@ async fn run_terminal(
                         {
                             let _ = writer.write_all(&[5, 5, 0, 1, 0, 0, 0, 0, 0, 0]).await;
                         }
-                        opened_streams.remove(&reject.stream_id);
-                        stream_send_credit.remove(&reject.stream_id);
-                        stream_pending_data.remove(&reject.stream_id);
-                        stream_next_send_offset.remove(&reject.stream_id);
-                        stream_sent_data.remove(&reject.stream_id);
-                        stream_next_recv_offset.remove(&reject.stream_id);
-                        stream_recv_pending.remove(&reject.stream_id);
+                        cleanup_stream_state(
+                            reject.stream_id,
+                            &mut opened_streams,
+                            &mut stream_send_credit,
+                            &mut stream_pending_data,
+                            &mut stream_pending_opens,
+                            &mut stream_next_send_offset,
+                            &mut stream_sent_data,
+                            &mut stream_next_recv_offset,
+                            &mut stream_recv_pending,
+                        );
                         stream_writers.remove(&reject.stream_id);
                     }
                     PacketKind::StreamData => {
@@ -5097,14 +5105,17 @@ async fn run_terminal(
                         };
                         last_packet_at = Instant::now();
                         pending_socks_replies.remove(&close.stream_id);
-                        stream_pending_opens.remove(&close.stream_id);
-                        opened_streams.remove(&close.stream_id);
-                        stream_send_credit.remove(&close.stream_id);
-                        stream_pending_data.remove(&close.stream_id);
-                        stream_next_send_offset.remove(&close.stream_id);
-                        stream_sent_data.remove(&close.stream_id);
-                        stream_next_recv_offset.remove(&close.stream_id);
-                        stream_recv_pending.remove(&close.stream_id);
+                        cleanup_stream_state(
+                            close.stream_id,
+                            &mut opened_streams,
+                            &mut stream_send_credit,
+                            &mut stream_pending_data,
+                            &mut stream_pending_opens,
+                            &mut stream_next_send_offset,
+                            &mut stream_sent_data,
+                            &mut stream_next_recv_offset,
+                            &mut stream_recv_pending,
+                        );
                         stream_writers.remove(&close.stream_id);
                         #[cfg(unix)]
                         agent_writers.remove(&close.stream_id);
@@ -5156,14 +5167,17 @@ async fn run_terminal(
                     }
                     Some(ForwardEvent::Close { stream_id }) => {
                         pending_socks_replies.remove(&stream_id);
-                        stream_pending_opens.remove(&stream_id);
-                        opened_streams.remove(&stream_id);
-                        stream_send_credit.remove(&stream_id);
-                        stream_pending_data.remove(&stream_id);
-                        stream_next_send_offset.remove(&stream_id);
-                        stream_sent_data.remove(&stream_id);
-                        stream_next_recv_offset.remove(&stream_id);
-                        stream_recv_pending.remove(&stream_id);
+                        cleanup_stream_state(
+                            stream_id,
+                            &mut opened_streams,
+                            &mut stream_send_credit,
+                            &mut stream_pending_data,
+                            &mut stream_pending_opens,
+                            &mut stream_next_send_offset,
+                            &mut stream_sent_data,
+                            &mut stream_next_recv_offset,
+                            &mut stream_recv_pending,
+                        );
                         stream_writers.remove(&stream_id);
                         #[cfg(unix)]
                         agent_writers.remove(&stream_id);
@@ -5760,6 +5774,7 @@ fn stale_mouse_report_len(bytes: &[u8], offset: usize) -> Option<usize> {
         },
         byte if byte.is_ascii_digit() => mouse_report_params_len(bytes, offset, 1)
             .or_else(|| orphan_mouse_suffix_len(bytes, offset)),
+        b'M' | b'm' if offset == 0 => orphan_leading_mouse_terminator_len(bytes, offset),
         _ => None,
     }
 }
@@ -5796,6 +5811,13 @@ fn orphan_mouse_suffix_len(bytes: &[u8], offset: usize) -> Option<usize> {
     None
 }
 
+fn orphan_leading_mouse_terminator_len(bytes: &[u8], offset: usize) -> Option<usize> {
+    if offset != 0 || !matches!(bytes.get(offset), Some(b'M' | b'm')) {
+        return None;
+    }
+    mouse_report_params_len(bytes, offset + 1, 1).map(|len| len + 1)
+}
+
 fn stale_mouse_report_maybe_incomplete(bytes: &[u8], offset: usize) -> bool {
     let Some(rest) = bytes.get(offset..) else {
         return false;
@@ -6136,6 +6158,28 @@ fn accept_stream_data(
     (writes, consumed, *expected)
 }
 
+#[allow(clippy::too_many_arguments)]
+fn cleanup_stream_state(
+    stream_id: u64,
+    opened_streams: &mut HashSet<u64>,
+    stream_send_credit: &mut HashMap<u64, usize>,
+    stream_pending_data: &mut HashMap<u64, VecDeque<Vec<u8>>>,
+    stream_pending_opens: &mut HashMap<u64, PendingStreamOpen>,
+    stream_next_send_offset: &mut HashMap<u64, u64>,
+    stream_sent_data: &mut HashMap<u64, BTreeMap<u64, PendingStreamChunk>>,
+    stream_next_recv_offset: &mut HashMap<u64, u64>,
+    stream_recv_pending: &mut HashMap<u64, BTreeMap<u64, Vec<u8>>>,
+) {
+    opened_streams.remove(&stream_id);
+    stream_send_credit.remove(&stream_id);
+    stream_pending_data.remove(&stream_id);
+    stream_pending_opens.remove(&stream_id);
+    stream_next_send_offset.remove(&stream_id);
+    stream_sent_data.remove(&stream_id);
+    stream_next_recv_offset.remove(&stream_id);
+    stream_recv_pending.remove(&stream_id);
+}
+
 fn ack_stream_data(
     stream_sent_data: &mut HashMap<u64, BTreeMap<u64, PendingStreamChunk>>,
     stream_send_credit: &mut HashMap<u64, usize>,
@@ -6296,6 +6340,60 @@ const FLAG_TRIGGER_LOW_MS: f64 = 50.0;
 /// (covers a sudden latency spike on the very first slow keystroke).
 const GLITCH_FORCE_MS: u128 = 250;
 
+/// Enough recent bytes to join a CSI private-mode sequence split across frames
+/// without retaining arbitrary terminal output.
+const TERMINAL_OUTPUT_PARSE_TAIL: usize = 64;
+
+fn alternate_screen_after_output(mut active: bool, bytes: &[u8]) -> bool {
+    let mut offset = 0usize;
+    while offset < bytes.len() {
+        let Some((next, transition)) = terminal_private_mode_transition(bytes, offset) else {
+            offset += 1;
+            continue;
+        };
+        if let Some(enable) = transition {
+            active = enable;
+        }
+        offset = next.max(offset + 1);
+    }
+    active
+}
+
+fn terminal_private_mode_transition(bytes: &[u8], offset: usize) -> Option<(usize, Option<bool>)> {
+    let mut cursor = offset;
+    match bytes.get(cursor).copied()? {
+        0x1b if bytes.get(cursor + 1) == Some(&b'[') => cursor += 2,
+        0x9b => cursor += 1,
+        _ => return None,
+    }
+
+    if bytes.get(cursor) != Some(&b'?') {
+        return None;
+    }
+    cursor += 1;
+
+    let params_start = cursor;
+    while let Some(byte) = bytes.get(cursor).copied() {
+        match byte {
+            b'0'..=b'9' | b';' | b':' => cursor += 1,
+            b'h' | b'l' => {
+                let params = &bytes[params_start..cursor];
+                let touches_alt = terminal_private_params_include_alt_screen(params);
+                return Some((cursor + 1, touches_alt.then_some(byte == b'h')));
+            }
+            0x40..=0x7e => return Some((cursor + 1, None)),
+            _ => return None,
+        }
+    }
+    None
+}
+
+fn terminal_private_params_include_alt_screen(params: &[u8]) -> bool {
+    params
+        .split(|byte| matches!(byte, b';' | b':'))
+        .any(|param| matches!(param, b"47" | b"1047" | b"1049"))
+}
+
 /// One speculatively-echoed character on the current line.
 #[derive(Clone, Debug)]
 struct PredictedCell {
@@ -6313,6 +6411,9 @@ struct Predictor {
     /// as vim/htop); we never speculate there because we cannot model arbitrary
     /// cursor addressing safely.
     alternate_screen: bool,
+    /// Tail of recent terminal output, retained so alternate-screen transitions
+    /// split across UDP frames are still detected.
+    output_parse_tail: Vec<u8>,
 
     /// Predicted cells for the current line, left-to-right starting at the
     /// column where the cursor sat when this run of predictions began.
@@ -6359,6 +6460,7 @@ impl Predictor {
             mode,
             enabled: enabled && mode != PredictMode::Off,
             alternate_screen: false,
+            output_parse_tail: Vec::new(),
             cells: Vec::new(),
             cursor: 0,
             epoch: 1,
@@ -6381,6 +6483,7 @@ impl Predictor {
         self.epoch += 1;
         self.confirmed_epoch = self.epoch - 1;
         self.alternate_screen = false;
+        self.output_parse_tail.clear();
         self.oldest_pending_at = None;
     }
 
@@ -6537,20 +6640,20 @@ impl Predictor {
     /// and confirms outstanding predictions: a fresh frame means the server has
     /// re-rendered the line, so our speculative glyphs are superseded and erased.
     fn observe_output(&mut self, bytes: &[u8]) {
-        if contains_bytes(bytes, b"\x1b[?1049h")
-            || contains_bytes(bytes, b"\x1b[?1047h")
-            || contains_bytes(bytes, b"\x1b[?47h")
-        {
-            self.alternate_screen = true;
-            let _ = self.discard_all();
-        }
-        if contains_bytes(bytes, b"\x1b[?1049l")
-            || contains_bytes(bytes, b"\x1b[?1047l")
-            || contains_bytes(bytes, b"\x1b[?47l")
-        {
-            self.alternate_screen = false;
+        let mut parse = Vec::with_capacity(self.output_parse_tail.len() + bytes.len());
+        parse.extend_from_slice(&self.output_parse_tail);
+        parse.extend_from_slice(bytes);
+
+        let before = self.alternate_screen;
+        self.alternate_screen = alternate_screen_after_output(self.alternate_screen, &parse);
+        if self.alternate_screen != before {
             let _ = self.discard_all();
         }
+
+        self.output_parse_tail.clear();
+        let keep = parse.len().min(TERMINAL_OUTPUT_PARSE_TAIL);
+        self.output_parse_tail
+            .extend_from_slice(&parse[parse.len().saturating_sub(keep)..]);
     }
 
     /// Sample SRTT from a newly arrived frame and confirm/clear outstanding
@@ -6864,8 +6967,8 @@ fn contains_bytes(haystack: &[u8], needle: &[u8]) -> bool {
         .any(|window| window == needle)
 }
 
-const FRAME_GAP_RESYNC_AFTER_MS: u64 = 2_500;
-const FRAME_GAP_RESYNC_COOLDOWN_MS: u64 = 5_000;
+const FRAME_GAP_RESYNC_AFTER_MS: u64 = 250;
+const FRAME_GAP_RESYNC_COOLDOWN_MS: u64 = 1_000;
 const FRAME_GAP_PENDING_RESYNC_THRESHOLD: usize = 128;
 
 #[derive(Default)]
@@ -7344,10 +7447,13 @@ const TERMINAL_CLEANUP: &[u8] = concat!(
     "\x1b[?1002l",
     "\x1b[?1001l",
     "\x1b[?1000l",
+    "\x1b[?1004l",
     "\x1b[?1015l",
     "\x1b[?1006l",
     "\x1b[?1005l",
     "\x1b[?2004l",
+    "\x1b[?47l",
+    "\x1b[?1047l",
     "\x1b[?1049l"
 )
 .as_bytes();
@@ -7359,28 +7465,30 @@ mod tests {
         FRAME_GAP_RESYNC_AFTER_MS, FrameBuffer, LocalForward, MAX_PENDING_USER_INPUT_BYTES,
         POST_SUBMIT_ALL_INPUT_HOLD, PendingStreamOpen, PredictMode, Predictor,
         RESTART_STATUS_SCRIPT, RemoteForward, STARTUP_INPUT_HOLD, SshConfig, StartupGateMode,
-        StatusAction, auth_allows, cache_key, cache_server_prefix, clear_cached_credentials,
-        ensure_tui_safe_status_overlay, input_contains_focus_in, input_matches_escape,
-        is_local_status_target, is_resume_response_for_client, latest_release_download_url,
-        load_first_native_identity_with_prompt, parse_dynamic_forward, parse_escape_key,
-        parse_local_forward, parse_remote_forward, parse_ssh_config, post_submit_hold_duration,
-        queue_pending_user_input, raw_contains_host_table, recv_response_until, refresh_live_addr,
-        release_tag_download_url, release_tag_from_effective_url, release_version_from_tag,
-        render_status_clear, render_status_overlay, requested_env, resolved_startup_command,
-        retransmit_stream_opens, rewrite_forward_command, selected_predict_mode, selected_udp_host,
-        server_version_mismatch, should_flush_terminal_input_after_contact,
-        should_hold_during_startup_gate, should_hold_post_submit_input,
-        should_repaint_idle_alternate_screen, split_after_command_submit, ssh_destination_host,
-        ssh_username, ssh_with_user, startup_command, status_ssh_target, strip_stale_mouse_reports,
-        strip_terminal_focus_reports, toml_bare_key_or_quoted, update_check_requested,
-        update_version_status, upsert_managed_block, valid_forward_host, vscode_safe_alias,
+        StatusAction, auth_allows, cache_key, cache_server_prefix, cleanup_stream_state,
+        clear_cached_credentials, ensure_tui_safe_status_overlay, input_contains_focus_in,
+        input_matches_escape, is_local_status_target, is_resume_response_for_client,
+        latest_release_download_url, load_first_native_identity_with_prompt, parse_dynamic_forward,
+        parse_escape_key, parse_local_forward, parse_remote_forward, parse_ssh_config,
+        post_submit_hold_duration, queue_pending_user_input, raw_contains_host_table,
+        recv_response_until, refresh_live_addr, release_tag_download_url,
+        release_tag_from_effective_url, release_version_from_tag, render_status_clear,
+        render_status_overlay, requested_env, resolved_startup_command, retransmit_stream_opens,
+        rewrite_forward_command, selected_predict_mode, selected_udp_host, server_version_mismatch,
+        should_flush_terminal_input_after_contact, should_hold_during_startup_gate,
+        should_hold_post_submit_input, should_repaint_idle_alternate_screen,
+        split_after_command_submit, ssh_destination_host, ssh_username, ssh_with_user,
+        startup_command, status_ssh_target, strip_stale_mouse_reports,
+        strip_terminal_focus_reports, terminal_private_mode_transition, toml_bare_key_or_quoted,
+        update_check_requested, update_version_status, upsert_managed_block, valid_forward_host,
+        vscode_safe_alias,
     };
     use dosh::config::{ClientConfig, CommandExtension, HostConfig};
     use dosh::native::EnvVar;
     use dosh::protocol::{self, Frame, PacketKind};
     use dosh::udp::is_transient_udp_send_error;
     use ed25519_dalek::{SigningKey, VerifyingKey};
-    use std::collections::{HashMap, VecDeque};
+    use std::collections::{BTreeMap, HashMap, VecDeque};
     use std::fs;
     use std::time::{Duration, Instant};
 
@@ -7426,6 +7534,100 @@ mod tests {
         assert_eq!(vscode_safe_alias(":///"), "host");
     }
 
+    #[test]
+    fn cleanup_stream_state_removes_all_per_stream_state_only_for_target() {
+        let stream_id = 42;
+        let other_stream_id = 43;
+        let mut opened_streams = std::collections::HashSet::from([stream_id, other_stream_id]);
+        let mut stream_send_credit = HashMap::from([(stream_id, 12), (other_stream_id, 34)]);
+        let mut stream_pending_data = HashMap::from([
+            (stream_id, VecDeque::from([vec![1]])),
+            (other_stream_id, VecDeque::from([vec![2]])),
+        ]);
+        let mut stream_pending_opens = HashMap::from([
+            (
+                stream_id,
+                PendingStreamOpen {
+                    target_host: "127.0.0.1".to_string(),
+                    target_port: 1234,
+                    last_sent: Instant::now(),
+                    attempts: 1,
+                },
+            ),
+            (
+                other_stream_id,
+                PendingStreamOpen {
+                    target_host: "127.0.0.1".to_string(),
+                    target_port: 1235,
+                    last_sent: Instant::now(),
+                    attempts: 1,
+                },
+            ),
+        ]);
+        let mut stream_next_send_offset = HashMap::from([(stream_id, 55), (other_stream_id, 66)]);
+        let mut stream_sent_data = HashMap::from([
+            (
+                stream_id,
+                BTreeMap::from([(
+                    0,
+                    super::PendingStreamChunk {
+                        offset: 0,
+                        bytes: vec![3],
+                        last_sent: Instant::now(),
+                        attempts: 1,
+                    },
+                )]),
+            ),
+            (
+                other_stream_id,
+                BTreeMap::from([(
+                    0,
+                    super::PendingStreamChunk {
+                        offset: 0,
+                        bytes: vec![4],
+                        last_sent: Instant::now(),
+                        attempts: 1,
+                    },
+                )]),
+            ),
+        ]);
+        let mut stream_next_recv_offset = HashMap::from([(stream_id, 77), (other_stream_id, 88)]);
+        let mut stream_recv_pending = HashMap::from([
+            (stream_id, BTreeMap::from([(77, vec![5])])),
+            (other_stream_id, BTreeMap::from([(88, vec![6])])),
+        ]);
+
+        cleanup_stream_state(
+            stream_id,
+            &mut opened_streams,
+            &mut stream_send_credit,
+            &mut stream_pending_data,
+            &mut stream_pending_opens,
+            &mut stream_next_send_offset,
+            &mut stream_sent_data,
+            &mut stream_next_recv_offset,
+            &mut stream_recv_pending,
+        );
+
+        assert!(!opened_streams.contains(&stream_id));
+        assert!(!stream_send_credit.contains_key(&stream_id));
+        assert!(!stream_pending_data.contains_key(&stream_id));
+        assert!(!stream_pending_opens.contains_key(&stream_id));
+        assert!(!stream_next_send_offset.contains_key(&stream_id));
+        assert!(!stream_sent_data.contains_key(&stream_id));
+        assert!(!stream_next_recv_offset.contains_key(&stream_id));
+        assert!(!stream_recv_pending.contains_key(&stream_id));
+
+        assert!(opened_streams.contains(&other_stream_id));
+        assert!(stream_send_credit.contains_key(&other_stream_id));
+        assert!(stream_pending_data.contains_key(&other_stream_id));
+        assert!(stream_pending_opens.contains_key(&other_stream_id));
+        assert!(stream_next_send_offset.contains_key(&other_stream_id));
+        assert!(stream_sent_data.contains_key(&other_stream_id));
+        assert!(stream_next_recv_offset.contains_key(&other_stream_id));
+        assert!(stream_recv_pending.contains_key(&other_stream_id));
+    }
+
     #[test]
     fn managed_ssh_block_is_replaced_not_duplicated() {
         let dir = tempfile::tempdir().unwrap();
@@ -7892,6 +8094,61 @@ mod tests {
         assert!(!predictor.alternate_screen);
     }
 
+    #[test]
+    fn predictor_tracks_legacy_and_combined_alternate_screen_modes() {
+        let mut predictor = Predictor::new(true);
+
+        predictor.observe_output(b"\x1b[?1000;1006;1049h");
+        assert!(predictor.alternate_screen);
+
+        predictor.observe_output(b"\x1b[?1006;1000l");
+        assert!(
+            predictor.alternate_screen,
+            "leaving mouse modes must not imply leaving alternate screen"
+        );
+
+        predictor.observe_output(b"\x1b[?1047l");
+        assert!(!predictor.alternate_screen);
+
+        predictor.observe_output(b"\x1b[?47h");
+        assert!(predictor.alternate_screen);
+        predictor.observe_output(b"\x1b[?47l");
+        assert!(!predictor.alternate_screen);
+    }
+
+    #[test]
+    fn predictor_tracks_alternate_screen_split_across_frames() {
+        let mut predictor = Predictor::new(true);
+
+        predictor.observe_output(b"\x1b");
+        assert!(!predictor.alternate_screen);
+        predictor.observe_output(b"[?");
+        assert!(!predictor.alternate_screen);
+        predictor.observe_output(b"10");
+        assert!(!predictor.alternate_screen);
+        predictor.observe_output(b"49h");
+        assert!(predictor.alternate_screen);
+
+        predictor.observe_output(b"\x1b");
+        assert!(predictor.alternate_screen);
+        predictor.observe_output(b"[?104");
+        assert!(predictor.alternate_screen);
+        predictor.observe_output(b"9l");
+        assert!(!predictor.alternate_screen);
+    }
+
+    #[test]
+    fn private_mode_parser_ignores_non_alt_modes() {
+        assert_eq!(
+            terminal_private_mode_transition(b"\x1b[?1000;1006h", 0),
+            Some((13, None))
+        );
+        assert_eq!(
+            terminal_private_mode_transition(b"\x1b[?1000;1049h", 0),
+            Some((13, Some(true)))
+        );
+    }
+
     /// Typing printable characters builds an in-order predicted line and the
     /// local cursor tracks the end of it.
     #[test]
@@ -8658,11 +8915,18 @@ mod tests {
         assert_eq!(strip_stale_mouse_reports(b"10m"), b"");
     }
 
+    #[test]
+    fn leading_mouse_terminator_from_split_report_is_stripped() {
+        assert_eq!(strip_stale_mouse_reports(b"M35;149;1Mls\r"), b"ls\r");
+        assert_eq!(strip_stale_mouse_reports(b"m35;149;1Mls\r"), b"ls\r");
+    }
+
     #[test]
     fn numeric_semicolon_input_survives_stale_filter() {
         assert_eq!(strip_stale_mouse_reports(b"123;"), b"123;");
         assert_eq!(strip_stale_mouse_reports(b"12;34"), b"12;34");
         assert_eq!(strip_stale_mouse_reports(b"echo 1;"), b"echo 1;");
+        assert_eq!(strip_stale_mouse_reports(b"make test"), b"make test");
     }
 
     #[test]

src/bin/dosh-server.rs

@@ -2133,11 +2133,7 @@ async fn handle_stream_open_reject(
     }
     client.endpoint = peer;
     client.last_seen = Instant::now();
-    client.stream_writers.remove(&reject.stream_id);
-    client.stream_pending_opens.remove(&reject.stream_id);
-    client.opened_streams.remove(&reject.stream_id);
-    client.stream_send_credit.remove(&reject.stream_id);
-    client.stream_pending_data.remove(&reject.stream_id);
+    cleanup_client_stream(client, reject.stream_id);
     Ok(())
 }
 
@@ -2192,15 +2188,7 @@ async fn handle_stream_close(
     // Connection migration on any authenticated, fresh packet (spec §11).
     client.endpoint = peer;
     client.last_seen = Instant::now();
-    client.stream_writers.remove(&close.stream_id);
-    client.stream_pending_opens.remove(&close.stream_id);
-    client.opened_streams.remove(&close.stream_id);
-    client.stream_send_credit.remove(&close.stream_id);
-    client.stream_pending_data.remove(&close.stream_id);
-    client.stream_next_send_offset.remove(&close.stream_id);
-    client.stream_sent_data.remove(&close.stream_id);
-    client.stream_next_recv_offset.remove(&close.stream_id);
-    client.stream_recv_pending.remove(&close.stream_id);
+    cleanup_client_stream(client, close.stream_id);
     Ok(())
 }
 
@@ -2667,10 +2655,13 @@ async fn handle_file_request(
             let (file, temp_path, written, atomic) = if resume && final_path.exists() {
                 let mut file = fs::OpenOptions::new()
                     .read(true)
+                    .write(true)
                     .append(true)
                     .open(&final_path)
                     .with_context(|| format!("open {}", final_path.display()))?;
                 let written = file.metadata()?.len().min(size);
+                file.set_len(written)
+                    .with_context(|| format!("truncate {}", final_path.display()))?;
                 if written > 0 {
                     let mut prefix = fs::File::open(&final_path)?;
                     hash_exact_prefix(&mut prefix, written, &mut hasher)?;
@@ -3277,6 +3268,18 @@ fn accept_stream_data(client: &mut ClientState, data: StreamData) -> (Vec<Vec<u8
     (writes, consumed, *expected)
 }
 
+fn cleanup_client_stream(client: &mut ClientState, stream_id: u64) {
+    client.stream_writers.remove(&stream_id);
+    client.stream_pending_opens.remove(&stream_id);
+    client.opened_streams.remove(&stream_id);
+    client.stream_send_credit.remove(&stream_id);
+    client.stream_pending_data.remove(&stream_id);
+    client.stream_next_send_offset.remove(&stream_id);
+    client.stream_sent_data.remove(&stream_id);
+    client.stream_next_recv_offset.remove(&stream_id);
+    client.stream_recv_pending.remove(&stream_id);
+}
+
 fn ack_stream_data(client: &mut ClientState, stream_id: u64, received_offset: u64) {
     let Some(sent) = client.stream_sent_data.get_mut(&stream_id) else {
         return;
@@ -3337,14 +3340,7 @@ async fn send_stream_close_to_client(
     {
         let mut locked = state.lock().expect("server state poisoned");
         if let Some(client) = locked.client_mut(&client_id) {
-            client.stream_writers.remove(&stream_id);
-            client.opened_streams.remove(&stream_id);
-            client.stream_send_credit.remove(&stream_id);
-            client.stream_pending_data.remove(&stream_id);
-            client.stream_next_send_offset.remove(&stream_id);
-            client.stream_sent_data.remove(&stream_id);
-            client.stream_next_recv_offset.remove(&stream_id);
-            client.stream_recv_pending.remove(&stream_id);
+            cleanup_client_stream(client, stream_id);
         }
     }
     let body = protocol::to_body(&StreamClose { stream_id })?;
@@ -4050,6 +4046,106 @@ mod tests {
         }
     }
 
+    #[test]
+    fn cleanup_client_stream_removes_all_per_stream_state_only_for_target() {
+        let stream_id = 42;
+        let other_stream_id = 43;
+        let mut client = test_client_state([7u8; 32]);
+        let (writer_tx, _writer_rx) = mpsc::channel(1);
+        client.stream_writers.insert(stream_id, writer_tx);
+        client.opened_streams.insert(stream_id);
+        client.opened_streams.insert(other_stream_id);
+        client.stream_send_credit.insert(stream_id, 12);
+        client.stream_send_credit.insert(other_stream_id, 34);
+        client
+            .stream_pending_data
+            .insert(stream_id, VecDeque::from([vec![1]]));
+        client
+            .stream_pending_data
+            .insert(other_stream_id, VecDeque::from([vec![2]]));
+        client.stream_pending_opens.insert(
+            stream_id,
+            PendingStreamOpen {
+                target_host: "127.0.0.1".to_string(),
+                target_port: 1234,
+                last_sent: Instant::now(),
+                attempts: 1,
+            },
+        );
+        client.stream_pending_opens.insert(
+            other_stream_id,
+            PendingStreamOpen {
+                target_host: "127.0.0.1".to_string(),
+                target_port: 1235,
+                last_sent: Instant::now(),
+                attempts: 1,
+            },
+        );
+        client.stream_next_send_offset.insert(stream_id, 55);
+        client.stream_next_send_offset.insert(other_stream_id, 66);
+        client.stream_sent_data.insert(
+            stream_id,
+            BTreeMap::from([(
+                0,
+                PendingStreamChunk {
+                    offset: 0,
+                    bytes: vec![3],
+                    last_sent: Instant::now(),
+                    attempts: 1,
+                },
+            )]),
+        );
+        client.stream_sent_data.insert(
+            other_stream_id,
+            BTreeMap::from([(
+                0,
+                PendingStreamChunk {
+                    offset: 0,
+                    bytes: vec![4],
+                    last_sent: Instant::now(),
+                    attempts: 1,
+                },
+            )]),
+        );
+        client.stream_next_recv_offset.insert(stream_id, 77);
+        client.stream_next_recv_offset.insert(other_stream_id, 88);
+        client
+            .stream_recv_pending
+            .insert(stream_id, BTreeMap::from([(77, vec![5])]));
+        client
+            .stream_recv_pending
+            .insert(other_stream_id, BTreeMap::from([(88, vec![6])]));
+
+        cleanup_client_stream(&mut client, stream_id);
+
+        assert!(!client.stream_writers.contains_key(&stream_id));
+        assert!(!client.opened_streams.contains(&stream_id));
+        assert!(!client.stream_send_credit.contains_key(&stream_id));
+        assert!(!client.stream_pending_data.contains_key(&stream_id));
+        assert!(!client.stream_pending_opens.contains_key(&stream_id));
+        assert!(!client.stream_next_send_offset.contains_key(&stream_id));
+        assert!(!client.stream_sent_data.contains_key(&stream_id));
+        assert!(!client.stream_next_recv_offset.contains_key(&stream_id));
+        assert!(!client.stream_recv_pending.contains_key(&stream_id));
+
+        assert!(client.opened_streams.contains(&other_stream_id));
+        assert!(client.stream_send_credit.contains_key(&other_stream_id));
+        assert!(client.stream_pending_data.contains_key(&other_stream_id));
+        assert!(client.stream_pending_opens.contains_key(&other_stream_id));
+        assert!(
+            client
+                .stream_next_send_offset
+                .contains_key(&other_stream_id)
+        );
+        assert!(client.stream_sent_data.contains_key(&other_stream_id));
+        assert!(
+            client
+                .stream_next_recv_offset
+                .contains_key(&other_stream_id)
+        );
+        assert!(client.stream_recv_pending.contains_key(&other_stream_id));
+    }
+
     #[test]
     fn client_index_stays_in_sync_with_session_clients() {
         let (pty_tx, _pty_rx) = mpsc::unbounded_channel();

src/transport.rs

@@ -121,6 +121,10 @@ pub struct AcceptedService {
 #[derive(Debug, Clone, PartialEq, Eq)]
 pub enum TransportEvent {
     Open(IncomingStreamOpen),
+    DuplicateOpen {
+        stream_id: u64,
+        response: OutgoingStreamPacket,
+    },
     OpenOk {
         stream_id: u64,
         flushed: Vec<OutgoingStreamPacket>,
@@ -258,6 +262,12 @@ impl StreamMux {
     }
 
     pub fn accept_open(&mut self, open: StreamOpen) -> Result<IncomingStreamOpen> {
+        if self.pending_opens.contains_key(&open.stream_id) {
+            bail!(
+                "stream {} collides with a local pending open",
+                open.stream_id
+            );
+        }
         self.opened_streams.insert(open.stream_id);
         self.send_credit
             .entry(open.stream_id)
@@ -309,8 +319,17 @@ impl StreamMux {
         if bytes.is_empty() {
             return Ok(Vec::new());
         }
-        if !self.opened_streams.contains(&stream_id)
-            || self.send_credit.get(&stream_id).copied().unwrap_or(0) < bytes.len()
+        if !self.opened_streams.contains(&stream_id) {
+            if self.pending_opens.contains_key(&stream_id) {
+                self.pending_data
+                    .entry(stream_id)
+                    .or_default()
+                    .push_back(bytes);
+                return Ok(Vec::new());
+            }
+            bail!("stream {stream_id} is not open");
+        }
+        if self.send_credit.get(&stream_id).copied().unwrap_or(0) < bytes.len()
             || self
                 .pending_data
                 .get(&stream_id)
@@ -367,6 +386,12 @@ impl StreamMux {
         match kind {
             PacketKind::StreamOpen => {
                 let open: StreamOpen = protocol::from_body(body)?;
+                if self.opened_streams.contains(&open.stream_id) {
+                    return Ok(TransportEvent::DuplicateOpen {
+                        stream_id: open.stream_id,
+                        response: Self::open_ok(open.stream_id)?,
+                    });
+                }
                 self.accept_open(open).map(TransportEvent::Open)
             }
             PacketKind::StreamOpenOk => {
@@ -625,7 +650,7 @@ impl DoshTransport {
             ack_seq: config.initial_ack,
             replay: ReplayWindow::default(),
             mux: StreamMux::new(config.stream),
-            next_stream_id: 1,
+            next_stream_id: initial_stream_id(config.role),
             last_contact: now,
             last_keepalive: now,
         }
@@ -669,7 +694,10 @@ impl DoshTransport {
 
     pub fn allocate_stream_id(&mut self) -> u64 {
         let id = self.next_stream_id;
-        self.next_stream_id = self.next_stream_id.saturating_add(1).max(1);
+        self.next_stream_id = self
+            .next_stream_id
+            .wrapping_add(1)
+            .max(initial_stream_id(self.role));
         id
     }
 
@@ -811,6 +839,9 @@ impl DoshTransport {
 
     async fn send_followups(&mut self, event: &TransportEvent) -> Result<()> {
         match event {
+            TransportEvent::DuplicateOpen { response, .. } => {
+                self.send_outgoing(response.clone()).await?;
+            }
             TransportEvent::OpenOk { flushed, .. }
             | TransportEvent::WindowAdjust { flushed, .. } => {
                 for packet in flushed.clone() {
@@ -857,6 +888,13 @@ impl DoshTransport {
     }
 }
 
+fn initial_stream_id(role: SessionRole) -> u64 {
+    match role {
+        SessionRole::Client => 1,
+        SessionRole::Server => 1u64 << 63,
+    }
+}
+
 pub fn service_target(name: &str) -> Result<String> {
     if name.is_empty()
         || !name
@@ -1047,6 +1085,152 @@ mod tests {
         );
     }
 
+    #[test]
+    fn duplicate_stream_open_reacks_without_second_open_event() {
+        let mut mux = StreamMux::new(TransportConfig::default());
+        let open = StreamOpen {
+            stream_id: 9,
+            target_host: "@dosh-app".to_string(),
+            target_port: 0,
+        };
+        let body = protocol::to_body(&open).unwrap();
+        assert!(matches!(
+            mux.handle_packet(PacketKind::StreamOpen, &body).unwrap(),
+            TransportEvent::Open(_)
+        ));
+
+        let duplicate = mux.handle_packet(PacketKind::StreamOpen, &body).unwrap();
+        match duplicate {
+            TransportEvent::DuplicateOpen {
+                stream_id,
+                response,
+            } => {
+                assert_eq!(stream_id, 9);
+                assert_eq!(response.kind, PacketKind::StreamOpenOk);
+                let ok: StreamOpenOk = decode(&response);
+                assert_eq!(ok.stream_id, 9);
+            }
+            other => panic!("unexpected duplicate open event {other:?}"),
+        }
+    }
+
+    #[test]
+    fn send_data_to_closed_or_unknown_stream_fails() {
+        let mut mux = StreamMux::new(TransportConfig::default());
+        mux.open_stream(1, "@dosh-test", 0).unwrap();
+        assert!(mux.send_data(1, b"queued".to_vec()).unwrap().is_empty());
+        mux.handle_open_ok(StreamOpenOk { stream_id: 1 }).unwrap();
+        mux.close_stream(1).unwrap();
+
+        assert!(mux.send_data(1, b"lost".to_vec()).is_err());
+        assert!(mux.send_data(99, b"lost".to_vec()).is_err());
+    }
+
+    #[tokio::test]
+    async fn session_transport_partitions_client_and_server_stream_ids() {
+        let client_socket = UdpSocket::bind("127.0.0.1:0").await.unwrap();
+        let server_socket = UdpSocket::bind("127.0.0.1:0").await.unwrap();
+        let client_addr = client_socket.local_addr().unwrap();
+        let server_addr = server_socket.local_addr().unwrap();
+        let key = [44u8; 32];
+        let conn_id = [8u8; 16];
+        let mut client = DoshTransport::new_owned(
+            client_socket,
+            SessionTransportConfig {
+                role: SessionRole::Client,
+                conn_id,
+                session_key: key,
+                peer_addr: server_addr,
+                initial_send_seq: 1,
+                initial_ack: 0,
+                stream: TransportConfig::default(),
+            },
+        );
+        let mut server = DoshTransport::new_owned(
+            server_socket,
+            SessionTransportConfig {
+                role: SessionRole::Server,
+                conn_id,
+                session_key: key,
+                peer_addr: client_addr,
+                initial_send_seq: 1,
+                initial_ack: 0,
+                stream: TransportConfig::default(),
+            },
+        );
+
+        assert_eq!(client.allocate_stream_id(), 1);
+        assert_eq!(client.allocate_stream_id(), 2);
+        assert_eq!(server.allocate_stream_id(), 1u64 << 63);
+        assert_eq!(server.allocate_stream_id(), (1u64 << 63) + 1);
+    }
+
+    #[tokio::test]
+    async fn session_transport_handles_simultaneous_opens_without_id_collision() {
+        let client_socket = UdpSocket::bind("127.0.0.1:0").await.unwrap();
+        let server_socket = UdpSocket::bind("127.0.0.1:0").await.unwrap();
+        let client_addr = client_socket.local_addr().unwrap();
+        let server_addr = server_socket.local_addr().unwrap();
+        let key = [45u8; 32];
+        let conn_id = [9u8; 16];
+        let mut client = DoshTransport::new_owned(
+            client_socket,
+            SessionTransportConfig {
+                role: SessionRole::Client,
+                conn_id,
+                session_key: key,
+                peer_addr: server_addr,
+                initial_send_seq: 1,
+                initial_ack: 0,
+                stream: TransportConfig::default(),
+            },
+        );
+        let mut server = DoshTransport::new_owned(
+            server_socket,
+            SessionTransportConfig {
+                role: SessionRole::Server,
+                conn_id,
+                session_key: key,
+                peer_addr: client_addr,
+                initial_send_seq: 1,
+                initial_ack: 0,
+                stream: TransportConfig::default(),
+            },
+        );
+
+        let client_stream = client.open_service("client_app").await.unwrap();
+        let server_stream = server.open_service("server_app").await.unwrap();
+        assert_ne!(client_stream, server_stream);
+
+        let server_seen = server.recv().await.unwrap();
+        let client_seen = client.recv().await.unwrap();
+        match server_seen {
+            SessionEvent::Stream(TransportEvent::Open(open)) => {
+                assert_eq!(open.stream_id, client_stream);
+                assert_eq!(open.target_host, "@dosh-client_app");
+                server.accept_stream(open.stream_id).await.unwrap();
+            }
+            other => panic!("unexpected server event {other:?}"),
+        }
+        match client_seen {
+            SessionEvent::Stream(TransportEvent::Open(open)) => {
+                assert_eq!(open.stream_id, server_stream);
+                assert_eq!(open.target_host, "@dosh-server_app");
+                client.accept_stream(open.stream_id).await.unwrap();
+            }
+            other => panic!("unexpected client event {other:?}"),
+        }
+
+        assert!(matches!(
+            client.recv().await.unwrap(),
+            SessionEvent::Stream(TransportEvent::OpenOk { stream_id, .. }) if stream_id == client_stream
+        ));
+        assert!(matches!(
+            server.recv().await.unwrap(),
+            SessionEvent::Stream(TransportEvent::OpenOk { stream_id, .. }) if stream_id == server_stream
+        ));
+    }
+
     #[tokio::test]
     async fn session_transport_opens_service_and_moves_data_over_encrypted_udp() {
         let client_socket = UdpSocket::bind("127.0.0.1:0").await.unwrap();

tests/integration_smoke.rs

@@ -1108,6 +1108,117 @@ fn native_file_copy_recursive_round_trip() {
     let _ = server.wait();
 }
 
+#[test]
+fn native_file_copy_resume_truncates_oversized_destinations() {
+    let dir = tempfile::tempdir().unwrap();
+    let port = free_udp_port();
+    let config = write_server_config(&dir, port);
+    write_native_client_auth(&dir, &config);
+    let mut server = start_server(&dir, &config);
+    let client_bin = env!("CARGO_BIN_EXE_dosh-client");
+
+    let local_short = dir.path().join("short.txt");
+    fs::write(&local_short, b"short\n").unwrap();
+
+    let seed_remote = Command::new(client_bin)
+        .arg("--dosh-host")
+        .arg("127.0.0.1")
+        .arg("--dosh-port")
+        .arg(port.to_string())
+        .arg("exec")
+        .arg("local")
+        .arg("printf 'short\\nSTALE' > \"$HOME/resume-upload.txt\"")
+        .env("HOME", dir.path())
+        .output()
+        .unwrap();
+    assert!(
+        seed_remote.status.success(),
+        "seed remote failed: stdout={} stderr={}",
+        String::from_utf8_lossy(&seed_remote.stdout),
+        String::from_utf8_lossy(&seed_remote.stderr)
+    );
+
+    let resume_upload = Command::new(client_bin)
+        .arg("--dosh-host")
+        .arg("127.0.0.1")
+        .arg("--dosh-port")
+        .arg(port.to_string())
+        .arg("cp")
+        .arg("--resume")
+        .arg(&local_short)
+        .arg("local:resume-upload.txt")
+        .env("HOME", dir.path())
+        .output()
+        .unwrap();
+    assert!(
+        resume_upload.status.success(),
+        "resume upload failed: stdout={} stderr={}",
+        String::from_utf8_lossy(&resume_upload.stdout),
+        String::from_utf8_lossy(&resume_upload.stderr)
+    );
+
+    let cat_upload = Command::new(client_bin)
+        .arg("--dosh-host")
+        .arg("127.0.0.1")
+        .arg("--dosh-port")
+        .arg(port.to_string())
+        .arg("cat")
+        .arg("local:resume-upload.txt")
+        .env("HOME", dir.path())
+        .output()
+        .unwrap();
+    assert!(
+        cat_upload.status.success(),
+        "cat upload failed: stdout={} stderr={}",
+        String::from_utf8_lossy(&cat_upload.stdout),
+        String::from_utf8_lossy(&cat_upload.stderr)
+    );
+    assert_eq!(String::from_utf8_lossy(&cat_upload.stdout), "short\n");
+
+    let seed_download = Command::new(client_bin)
+        .arg("--dosh-host")
+        .arg("127.0.0.1")
+        .arg("--dosh-port")
+        .arg(port.to_string())
+        .arg("exec")
+        .arg("local")
+        .arg("printf 'tiny\\n' > \"$HOME/resume-download.txt\"")
+        .env("HOME", dir.path())
+        .output()
+        .unwrap();
+    assert!(
+        seed_download.status.success(),
+        "seed download failed: stdout={} stderr={}",
+        String::from_utf8_lossy(&seed_download.stdout),
+        String::from_utf8_lossy(&seed_download.stderr)
+    );
+
+    let local_download = dir.path().join("resume-download-local.txt");
+    fs::write(&local_download, b"tiny\nSTALE").unwrap();
+    let resume_download = Command::new(client_bin)
+        .arg("--dosh-host")
+        .arg("127.0.0.1")
+        .arg("--dosh-port")
+        .arg(port.to_string())
+        .arg("cp")
+        .arg("--resume")
+        .arg("local:resume-download.txt")
+        .arg(&local_download)
+        .env("HOME", dir.path())
+        .output()
+        .unwrap();
+    assert!(
+        resume_download.status.success(),
+        "resume download failed: stdout={} stderr={}",
+        String::from_utf8_lossy(&resume_download.stdout),
+        String::from_utf8_lossy(&resume_download.stderr)
+    );
+    assert_eq!(fs::read_to_string(&local_download).unwrap(), "tiny\n");
+
+    let _ = server.kill();
+    let _ = server.wait();
+}
+
 #[test]
 fn native_exec_command_smoke() {
     let dir = tempfile::tempdir().unwrap();