fix: old links never re-create ended sessions

Inbox entries, the switcher, palette switches, the attention chip and Matrix
links (?arg=NAME&existing=1) attach with --existing; an ended session gets an
explanation and an explicit "Start again". Inbox entries for ended sessions
can't resurrect them; entries expire after 7 days.

Closes #38

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

debian/changelog

@@ -1,3 +1,25 @@
+devdesk (0.7.3) bookworm; urgency=medium
+
+  * Fix (#38): links that mean "go to that session" no longer re-create one
+    that was ended. The 🔔 inbox, the session switcher, palette switches, the
+    "needs you" chip and Matrix links (now ?arg=NAME&existing=1) open sessions
+    existing-only; an ended one shows "NAME has ended" with an explicit
+    "Start NAME again". Inbox entries for ended sessions are marked as such,
+    and entries older than 7 days are dropped.
+
+ -- Jared Vititoe <jjvititoe1@gmail.com>  Sat, 10 Oct 2026 19:57:52 -0400
+
+devdesk (0.7.2) bookworm; urgency=medium
+
+  * Fix: Go to file failed in big non-git folders such as /root/code: the
+    file walk was cut off at its cap with SIGPIPE, which failed the command
+    and truncated its reply. Producers piped into a cap now tolerate it (also
+    for very large folders and git status). Outside git, Go to file skips
+    build/cache folders and stops at 10,000 files.
+  * Large side-channel replies no longer cost quadratic time in the browser.
+
+ -- Jared Vititoe <jjvititoe1@gmail.com>  Thu, 08 Oct 2026 01:50:50 -0400
+
 devdesk (0.7.1) bookworm; urgency=medium
 
   * Files pane reworked like VS Code (#37):

libexec/devdesk-files.sh

@@ -7,6 +7,10 @@
 : "${DEVDESK_FS_LIST_MAX:=2000}"      # entries per directory listing
 : "${DEVDESK_ASSETS:=$DEVDESK_SHARE/assets}"
 
+# Producers piped into `head` get SIGPIPE once the cap is reached; under
+# pipefail that would fail the command and cut its reply short, so they are
+# wrapped as `{ producer || true; }`.
+
 # Blob replies: a JSON header line, then base64 between markers (no body for
 # binary files the viewer can't show). The client waits for the END marker.
 DD_BLOB_BEGIN=DEVDESK-BLOB-BEGIN
@@ -81,7 +85,7 @@ cmd_fs_list() {
     [ -d "$dir" ] || dd_die "not a folder: $rel"
     tmp=$(mktemp)
     # %y: type, %Y: type behind a symlink, %s: size, %T@: mtime, %f: name.
-    find "$dir" -mindepth 1 -maxdepth 1 ! -name .git -printf '%y\t%Y\t%s\t%T@\t%f\0' 2>/dev/null |
+    { find "$dir" -mindepth 1 -maxdepth 1 ! -name .git -printf '%y\t%Y\t%s\t%T@\t%f\0' 2>/dev/null || true; } |
         head -z -n "$((DEVDESK_FS_LIST_MAX + 1))" >"$tmp"
     if git --no-optional-locks -C "$dir" rev-parse --is-inside-work-tree >/dev/null 2>&1; then
         ignored=$(tr '\0' '\n' <"$tmp" | cut -f5- | git --no-optional-locks -C "$dir" check-ignore --stdin 2>/dev/null || true)
@@ -98,16 +102,18 @@ cmd_fs_list() {
 
 # --fs-find SESSION: every file under the session folder, for "go to file".
 # git ls-files in a repository (tracked + untracked, .gitignore honoured), else
-# find without node_modules and .git; capped at DEVDESK_FS_FIND_MAX.
+# find without node_modules, .git and build/cache folders; capped at
+# DEVDESK_FS_FIND_MAX (10000).
 cmd_fs_find() {
     [ $# -eq 1 ] || dd_die "usage: devdesk attach --fs-find SESSION"
-    local root max=${DEVDESK_FS_FIND_MAX:-20000}
+    local root max=${DEVDESK_FS_FIND_MAX:-10000}
     root=$(dd_session_root "$1")
     if git --no-optional-locks -C "$root" rev-parse --is-inside-work-tree >/dev/null 2>&1; then
-        git --no-optional-locks -C "$root" ls-files -co --exclude-standard -z 2>/dev/null
+        git --no-optional-locks -C "$root" ls-files -co --exclude-standard -z 2>/dev/null || true
     else
-        (cd "$root" && find . -maxdepth 8 \( -name node_modules -o -name .git -o -name __pycache__ -o -name .venv \) -prune \
-            -o -type f -printf '%P\0' 2>/dev/null)
+        (cd "$root" && find . -maxdepth 8 \( -name node_modules -o -name .git -o -name __pycache__ -o -name .venv -o -name venv \
+            -o -name dist -o -name build -o -name target -o -name .cache -o -name .next -o -name coverage \) -prune \
+            -o -type f -printf '%P\0' 2>/dev/null) || true
     fi | head -z -n "$((max + 1))" |
         jq -cMRs --argjson max "$max" --arg root "$root" \
             '(split("\u0000") | map(select(length > 0))) as $f | {root: $root, truncated: ($f | length > $max), files: $f[:$max]}'
@@ -142,9 +148,9 @@ cmd_git_status() {
     branch=$("${g[@]}" symbolic-ref --short -q HEAD || echo "(detached)")
     {
         printf 'S\n'
-        "${g[@]}" status --porcelain=v1 -z --untracked-files=all -- . 2>/dev/null | head -z -n 1000 | tr '\0' '\n'
+        { "${g[@]}" status --porcelain=v1 -z --untracked-files=all -- . 2>/dev/null || true; } | head -z -n 1000 | tr '\0' '\n'
         printf 'N\n'
-        "${g[@]}" diff --numstat HEAD -- . 2>/dev/null | head -n 1000
+        { "${g[@]}" diff --numstat HEAD -- . 2>/dev/null || true; } | head -n 1000
     } | jq -cMRs --arg root "$root" --arg top "$top" --arg prefix "$prefix" --arg branch "$branch" \
         --rawfile e <(cat -- "$edits" 2>/dev/null || true) '
         (split("\nN\n") | .[0] | ltrimstr("S\n") | split("\n") | map(select(length > 2))) as $st

libexec/devdesk-notify-matrix

@@ -28,7 +28,9 @@ attached=$(dd_tmux list-sessions -F '#{session_name} #{session_attached}' 2>/dev
 
 message=$(jq -rM '.message // "Claude is waiting for your input"' "$state_file" 2>/dev/null)
 url=""
-[ -z "$DEVDESK_PUBLIC_URL" ] || url="${DEVDESK_PUBLIC_URL%/}/?arg=$session"
+# existing=1: if the session was ended by the time you tap, say so instead of
+# starting a new Claude there (devdesk#38).
+[ -z "$DEVDESK_PUBLIC_URL" ] || url="${DEVDESK_PUBLIC_URL%/}/?arg=$session&existing=1"
 body=$(jq -cMn --arg s "$session" --arg m "$message" --arg u "$url" --arg h "$(hostname)" \
     '{session: $s, message: $m, url: (if $u == "" then null else $u end), host: $h,
       text: ("Claude needs you in " + $s + ": " + $m + (if $u == "" then "" else " — " + $u end))}')

tests/attach.bats

@@ -310,7 +310,7 @@ posts() { [ -f "$TMP/posts" ] && wc -l <"$TMP/posts" || echo 0; }
     sleep 2.5
     [ "$(posts)" -eq 1 ]
     run jq -r '[.session, .url, (.text | test("Claude needs you in alpha"))] | @tsv' "$TMP/posts"
-    [ "$output" = "$(printf 'alpha\thttps://dev.example.org/?arg=alpha\ttrue')" ]
+    [ "$output" = "$(printf 'alpha\thttps://dev.example.org/?arg=alpha&existing=1\ttrue')" ]
 
     # answered within the delay: nothing is posted
     echo '{"hook_event_name":"PostToolUse"}' | hook
@@ -611,6 +611,12 @@ blob_body() {
     rm -rf "$p/.git"
     run devdesk attach --fs-find alpha
     [ "$(jq -r '.files | sort | join(",")' <<<"$output")" = ".gitignore,debug.log,src/a.js" ]
+    # Hitting the cap must not fail the command (SIGPIPE in the producer).
+    for i in $(seq 1 3000); do : >"$p/src/f$i.txt"; done
     run env DEVDESK_FS_FIND_MAX=1 "$REPO/bin/devdesk" attach --fs-find alpha
+    [ "$status" -eq 0 ]
     [ "$(jq -r '[(.files | length), .truncated] | @tsv' <<<"$output")" = "$(printf '1\ttrue')" ]
+    run env DEVDESK_FS_LIST_MAX=5 "$REPO/bin/devdesk" attach --fs-list alpha src
+    [ "$status" -eq 0 ]
+    [ "$(jq -r '[(.entries | length), .truncated] | @tsv' <<<"$output")" = "$(printf '5\ttrue')" ]
 }

web/src/connection.js

@@ -152,13 +152,21 @@ async function runCommandNow(args, timeoutMs) {
       clearTimeout(timer);
       resolve(new TextDecoder().decode(concat(chunks)));
     };
+    const decoder = new TextDecoder();
+    let head = '';
+    let tail = '';
     socket.onmessage = (event) => {
       const { type, payload } = decodeServer(event.data);
       if (type !== Server.OUTPUT) return;
       chunks.push(payload.slice());
+      const piece = decoder.decode(payload, { stream: true });
+      if (head.length < 4096) head += piece;
+      tail = (tail + piece).slice(-64);
       // Hang up as soon as the answer is complete: devdesk waits for that
       // before exiting, so ttyd can't drop its last output (devdesk#35).
-      if (isComplete(new TextDecoder().decode(concat(chunks)))) {
+      // Replies are one JSON line (or a devdesk: error), so only a chunk that
+      // ends a line with "}" is worth a full parse; big replies stay linear.
+      if (/^devdesk: .*\n/m.test(head) || (/\}\s*\n\s*$/.test(tail) && isComplete(new TextDecoder().decode(concat(chunks))))) {
         finish();
         socket.close();
       }

web/src/files.js

@@ -406,7 +406,7 @@ export class FilesPane {
 
   async loadFileList() {
     if (this.fileList && Date.now() - this.fileList.at < 60000 && this.fileList.session === this.session) return this.fileList.items;
-    const list = parseListOutput(await runCommand(['--fs-find', this.session], 20000));
+    const list = parseListOutput(await runCommand(['--fs-find', this.session], 45000));
     const items = list.files.map((path) => {
       const name = base(path);
       const [icon] = iconFor(name);

web/src/inbox.js

@@ -8,11 +8,12 @@ import { ago } from './sessions.js';
 
 const KEY = 'devdesk.inbox';
 const MAX = 30;
+const MAX_AGE = 7 * 86400 * 1000;
 
 function load() {
   try {
     const list = JSON.parse(localStorage.getItem(KEY) || '[]');
-    return Array.isArray(list) ? list : [];
+    return Array.isArray(list) ? list.filter((e) => Date.now() - e.at < MAX_AGE) : [];
   } catch {
     return [];
   }
@@ -45,6 +46,7 @@ export class Inbox {
     this.events = load();
     this.waiting = [];
     this.alerts = [];
+    this.known = null; // session names that exist, once the list has loaded
     this.list = panel.querySelector('.lt-notif-panel-list');
     panel.querySelector('.lt-notif-panel-clear').addEventListener('click', () => this.markAllRead());
     window.addEventListener('storage', (event) => {
@@ -78,9 +80,10 @@ export class Inbox {
   }
 
   // Live state: other sessions waiting on you, firing alerts.
-  setLive({ waiting, alerts }) {
+  setLive({ waiting, alerts, sessions }) {
     if (waiting) this.waiting = waiting;
     if (alerts) this.alerts = alerts;
+    if (sessions) this.known = new Set(sessions);
     this.render();
   }
 
@@ -91,7 +94,7 @@ export class Inbox {
   }
 
   unread() {
-    return this.events.filter((e) => !e.read && e.kind !== 'waiting').length;
+    return this.events.filter((e) => !e.read && e.kind !== 'waiting' && !(this.known && e.session && !e.url && !this.known.has(e.session))).length;
   }
 
   render() {
@@ -155,12 +158,16 @@ export class Inbox {
       nodes.push(el('div', { class: 'dd-notif-section' }, 'Recent'));
       for (const e of recent.slice(0, 12)) {
         const kind = KINDS[e.kind] ?? { tone: 'cyan' };
+        // An entry about a session that has since ended must not bring it back (devdesk#38).
+        const ended = !e.url && e.session && this.known && !this.known.has(e.session);
         nodes.push(item({
-          dot: e.read ? 'read' : kind.tone, unread: !e.read, title: e.text, meta: when(e.at),
+          dot: e.read || ended ? 'read' : kind.tone, unread: !e.read && !ended, title: e.text,
+          meta: `${when(e.at)}${ended ? ' · session ended' : ''}`,
           onclick: close(() => {
             this.events = this.events.map((x) => (x.id === e.id ? { ...x, read: true } : x));
             save(this.events);
             if (e.url) window.open(e.url, '_blank', 'noopener');
+            else if (ended) this.hooks.ended?.(e.session);
             else if (e.session) this.hooks.openSession(e.session);
           }),
         }));

web/src/main.js

@@ -58,6 +58,8 @@ const ui = {
 };
 
 const urlSession = sessionFromSearch(window.location.search);
+// Notification links (Matrix) add existing=1: open, never re-create (devdesk#38).
+const urlExisting = new URLSearchParams(window.location.search).get('existing') === '1';
 const state = {
   session: urlSession, // null = picker
   conn: null,
@@ -169,7 +171,11 @@ function recordTransitions(sessions) {
 }
 
 function renderPanelsBadge() {
-  inbox?.setLive({ waiting: waitingOthers, alerts: lastAlerts?.alerts ?? [] });
+  inbox?.setLive({
+    waiting: waitingOthers,
+    alerts: lastAlerts?.alerts ?? [],
+    sessions: sessionsPanel?.data ? sessionsPanel.data.sessions.map((x) => x.name) : null,
+  });
 }
 
 function onSessionData({ fetched = false } = {}) {
@@ -316,14 +322,19 @@ function updateUrl(session) {
   const url = new URL(window.location.href);
   if (session) url.searchParams.set('arg', session);
   else url.searchParams.delete('arg');
+  url.searchParams.delete('existing');
   if (url.href !== window.location.href) window.history.replaceState(null, '', url);
 }
 
 // ---------------------------------------------------------------- connection
 
-// reconnect: automatic re-attach after a drop. It must not re-create a session
-// that was ended or renamed meanwhile, so it asks for --existing (devdesk#4).
-function connect(session, { reconnect = false } = {}) {
+// existing: go to a session that should already exist (reconnects, the
+// switcher, inbox entries, notification links). It must not re-create one that
+// was ended or renamed meanwhile, so it asks for --existing (devdesk#4, #38).
+// Creating is explicit: a typed name, the New dialog, the picker, recents.
+function connect(session, { existing = false, reconnect = false } = {}) {
+  const existingOnly = Boolean(session) && (existing || reconnect);
+  state.existingOnly = existingOnly;
   clearTimeout(state.retryTimer);
   state.conn?.dispose();
   state.session = session;
@@ -339,7 +350,7 @@ function connect(session, { reconnect = false } = {}) {
   term.reset();
 
   const conn = new TtydConnection({
-    arg: session && reconnect ? ['--existing', session] : session,
+    arg: existingOnly ? ['--existing', session] : session,
     size: () => ({ cols: term.cols, rows: term.rows }),
     onOpen: () => {
       state.openedAt = Date.now();
@@ -373,6 +384,25 @@ function onClosed(code) {
   // few seconds of opening means the session could not start (the reason is
   // printed in the terminal), so don't retry forever.
   const failedFast = code !== 1000 && Date.now() - state.openedAt < 4000;
+  if (failedFast && state.existingOnly) {
+    // Most likely ended or renamed since the link was made: say so, and only
+    // start it again when asked.
+    const name = state.session;
+    sessionsPanel?.reload().then(() => {
+      const known = sessionsPanel.data?.sessions?.some((x) => x.name === name);
+      if (known) {
+        scheduleReconnect();
+        return;
+      }
+      setWsState('disconnected', 'ended');
+      showOverlay({
+        title: `${name} has ended`,
+        text: `The session "${name}" no longer exists: it was ended or renamed. Its conversation is still in Claude's history.`,
+        actions: [pickerAction, { label: `Start ${name} again`, run: () => connect(name) }],
+      });
+    });
+    return;
+  }
   if (failedFast) {
     showOverlay({
       title: 'Session did not start',
@@ -515,7 +545,7 @@ function renderSwitcher() {
     return el('button', {
       type: 'button', role: 'menuitem',
       class: `dd-menu-item dd-switch-item is-${status.key}${s.name === state.session ? ' is-current' : ''}`,
-      title: s.dir || '', onclick: choose(() => connect(s.name)),
+      title: s.dir || '', onclick: choose(() => connect(s.name, { existing: true })),
     },
     el('span', { class: `lt-dot ${status.dot}` }),
     el('span', { class: 'dd-switch-name' }, s.name),
@@ -591,7 +621,7 @@ function buildCommands() {
     const status = sessionStatus(s);
     add({
       id: `switch:${s.name}`, group: 'Sessions', label: `Switch to ${s.name}`, hint: status.label, keywords: s.dir,
-      icon: status.key === 'waiting' ? '!' : s.running ? '●' : '○', run: () => connect(s.name),
+      icon: status.key === 'waiting' ? '!' : s.running ? '●' : '○', run: () => connect(s.name, { existing: true }),
     });
   }
   add({ id: 'new', group: 'Sessions', icon: '+', label: 'New session…', keywords: 'create open project', run: () => sessionsPanel.newDialog() });
@@ -866,7 +896,8 @@ function wireChrome() {
     badge: $('inbox-badge'),
     panel: $('inbox-panel'),
     hooks: {
-      openSession: (name) => connect(name),
+      openSession: (name) => connect(name, { existing: true }),
+      ended: (name) => toast.info(`${name} has ended; its conversation is still in Claude's history`),
       showAlerts: () => {
         setSidebar(true);
         $('widget-alerts').scrollIntoView({ block: 'start', behavior: 'smooth' });
@@ -957,7 +988,7 @@ function wireChrome() {
     if (!document.hidden && ui.body.classList.contains('dd-sidebar-open')) refreshRepo();
   }, 60 * 1000);
   ui.attention.addEventListener('click', () => {
-    if (ui.attention.dataset.target) connect(ui.attention.dataset.target);
+    if (ui.attention.dataset.target) connect(ui.attention.dataset.target, { existing: true });
   });
 }
 
@@ -1057,7 +1088,8 @@ async function boot() {
   wireUploads();
   refreshAlerts();
   await sessionsPanel.refresh();
-  connect(urlSession ?? defaultSession(sessionsPanel.data));
+  if (urlSession) connect(urlSession, { existing: urlExisting });
+  else connect(defaultSession(sessionsPanel.data), { existing: true });
 }
 
 boot();