consume the fork source on first bind (T-375)

widget.forkSourceId took precedence over the fresh/resume logic on
EVERY (re)bind, so /clear in a fork pane re-forked the original
conversation instead of clearing, and /resume re-forked the same way.
The source is now copied into one-shot pane state and cleared after
the first successful fork spawn; later respawns operate on the pane's
own session.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

.pql/changelog/ticket_history/2026-06.sql

@@ -4001,3 +4001,5 @@ INSERT INTO ticket_history (ticket_record_id, field, old_value, new_value, chang
 INSERT INTO ticket_history (ticket_record_id, field, old_value, new_value, changed_by, changed_at, created_at, updated_at, deleted_at, hash, canonical_version) VALUES ('06FBHCP03EJ9CDBGZGRPD19N8W', 'status', 'in_progress', 'done', NULL, '2026-06-11 23:06:26', '2026-06-11 23:06:26', '2026-06-11 23:06:26', NULL, '4e1cc82f703d717f7592890e230caf00', 2) ON CONFLICT(hash) DO NOTHING;
 INSERT INTO ticket_history (ticket_record_id, field, old_value, new_value, changed_by, changed_at, created_at, updated_at, deleted_at, hash, canonical_version) VALUES ('06FBHC90B72A270CAKA7AP1ZX8', 'status', 'backlog', 'in_progress', NULL, '2026-06-11 23:07:01', '2026-06-11 23:07:01', '2026-06-11 23:07:01', NULL, '795c139edb5acd0d2a187dac6a3066c7', 2) ON CONFLICT(hash) DO NOTHING;
 INSERT INTO ticket_history (ticket_record_id, field, old_value, new_value, changed_by, changed_at, created_at, updated_at, deleted_at, hash, canonical_version) VALUES ('06FBHC90B72A270CAKA7AP1ZX8', 'status', 'in_progress', 'done', NULL, '2026-06-11 23:08:13', '2026-06-11 23:08:13', '2026-06-11 23:08:13', NULL, 'f83a2fc13f3839070957bea6ac7fdc5f', 2) ON CONFLICT(hash) DO NOTHING;
+INSERT INTO ticket_history (ticket_record_id, field, old_value, new_value, changed_by, changed_at, created_at, updated_at, deleted_at, hash, canonical_version) VALUES ('06FBHCAFKK334YNJXZJQG4J6AW', 'status', 'backlog', 'in_progress', NULL, '2026-06-11 23:08:40', '2026-06-11 23:08:40', '2026-06-11 23:08:40', NULL, 'd61ecda5f46b3ad0e15ea566bc83a52c', 2) ON CONFLICT(hash) DO NOTHING;
+INSERT INTO ticket_history (ticket_record_id, field, old_value, new_value, changed_by, changed_at, created_at, updated_at, deleted_at, hash, canonical_version) VALUES ('06FBHCAFKK334YNJXZJQG4J6AW', 'status', 'in_progress', 'done', NULL, '2026-06-11 23:10:56', '2026-06-11 23:10:56', '2026-06-11 23:10:56', NULL, '4b505b885dc39785651e259370fbc97b', 2) ON CONFLICT(hash) DO NOTHING;

.pql/changelog/tickets/2026-06.sql

@@ -4109,3 +4109,13 @@ INSERT INTO tickets (record_id, type, parent_record_id, title, description, stat
 Fix: hold a Map<String, Future<ManagedSession>> — first caller installs the future synchronously, later callers await the same future; remove the entry on failure.
 
 Acceptance: test issuing two concurrent spawn() calls for one id yields the same ManagedSession instance and exactly one process spawn (count via injected spawner); failure path clears the in-flight entry so a retry can proceed.', 'done', 'medium', NULL, NULL, NULL, '2026-06-11 21:57:56', '2026-06-11 23:08:13', NULL, 'fde3f9e912ea1d25256003ef56dcf491', 2) ON CONFLICT(record_id) DO UPDATE SET type=excluded.type, parent_record_id=excluded.parent_record_id, title=excluded.title, description=excluded.description, status=excluded.status, priority=excluded.priority, assigned_to=excluded.assigned_to, team=excluded.team, decision_ref=excluded.decision_ref, updated_at=excluded.updated_at, deleted_at=excluded.deleted_at, hash=excluded.hash, canonical_version=excluded.canonical_version WHERE excluded.updated_at > tickets.updated_at OR (excluded.updated_at = tickets.updated_at AND excluded.hash > tickets.hash);
+INSERT INTO tickets (record_id, type, parent_record_id, title, description, status, priority, assigned_to, team, decision_ref, created_at, updated_at, deleted_at, hash, canonical_version) VALUES ('06FBHCAFKK334YNJXZJQG4J6AW', 'bug', '06FBHBGHNEQTAEPGNJKN42C1E8', 'Fork panes: widget.forkSourceId wins forever — /clear re-forks the original conversation', 'lib/builtin/claude/src/claude_pane.dart:266-281 — when (re)binding a session, widget.forkSourceId takes precedence forever, so /clear in a fork pane re-forks the original conversation instead of clearing, and /resume and /fork misbehave the same way. Related context: clide owns /clear, /resume, /compact interception (T-156); panes pin a session id.
+
+Fix: treat forkSourceId as a one-shot spawn parameter — consume it on first bind (clear it into pane state), so subsequent session-mutating commands operate on the pane''s live session.
+
+Acceptance: test that a fork pane after /clear starts an empty session (no fork source passed to the orchestrator on respawn); first bind still forks from the source.', 'in_progress', 'medium', NULL, NULL, NULL, '2026-06-11 21:58:08', '2026-06-11 23:08:40', NULL, '8e8a63e0617c3707db1cf5621f181b63', 2) ON CONFLICT(record_id) DO UPDATE SET type=excluded.type, parent_record_id=excluded.parent_record_id, title=excluded.title, description=excluded.description, status=excluded.status, priority=excluded.priority, assigned_to=excluded.assigned_to, team=excluded.team, decision_ref=excluded.decision_ref, updated_at=excluded.updated_at, deleted_at=excluded.deleted_at, hash=excluded.hash, canonical_version=excluded.canonical_version WHERE excluded.updated_at > tickets.updated_at OR (excluded.updated_at = tickets.updated_at AND excluded.hash > tickets.hash);
+INSERT INTO tickets (record_id, type, parent_record_id, title, description, status, priority, assigned_to, team, decision_ref, created_at, updated_at, deleted_at, hash, canonical_version) VALUES ('06FBHCAFKK334YNJXZJQG4J6AW', 'bug', '06FBHBGHNEQTAEPGNJKN42C1E8', 'Fork panes: widget.forkSourceId wins forever — /clear re-forks the original conversation', 'lib/builtin/claude/src/claude_pane.dart:266-281 — when (re)binding a session, widget.forkSourceId takes precedence forever, so /clear in a fork pane re-forks the original conversation instead of clearing, and /resume and /fork misbehave the same way. Related context: clide owns /clear, /resume, /compact interception (T-156); panes pin a session id.
+
+Fix: treat forkSourceId as a one-shot spawn parameter — consume it on first bind (clear it into pane state), so subsequent session-mutating commands operate on the pane''s live session.
+
+Acceptance: test that a fork pane after /clear starts an empty session (no fork source passed to the orchestrator on respawn); first bind still forks from the source.', 'done', 'medium', NULL, NULL, NULL, '2026-06-11 21:58:08', '2026-06-11 23:10:56', NULL, '1cd70120bb752815eeaebb58e57b1a1c', 2) ON CONFLICT(record_id) DO UPDATE SET type=excluded.type, parent_record_id=excluded.parent_record_id, title=excluded.title, description=excluded.description, status=excluded.status, priority=excluded.priority, assigned_to=excluded.assigned_to, team=excluded.team, decision_ref=excluded.decision_ref, updated_at=excluded.updated_at, deleted_at=excluded.deleted_at, hash=excluded.hash, canonical_version=excluded.canonical_version WHERE excluded.updated_at > tickets.updated_at OR (excluded.updated_at = tickets.updated_at AND excluded.hash > tickets.hash);

CHANGELOG.md

@@ -99,6 +99,11 @@ heading, and (b) bumping `pubspec.yaml` `version:` in the same commit.
   check and the loser's live process was orphaned; spawns for an id are now
   coalesced onto one in-flight future. (T-374)
 
+- **`/clear` in a fork pane clears instead of re-forking.** The fork source
+  took precedence on every respawn, so clearing a fork tab silently branched
+  the original conversation again; the source now seeds only the first
+  bind. (T-375)
+
 - **Accepting ExitPlanMode now leaves plan mode in the conversation panel.**
   Approving Claude's plan (the ExitPlanMode tool) transitioned the underlying
   session out of plan mode, but clide's tracked permission mode didn't follow,

lib/builtin/claude/src/claude_pane.dart

@@ -81,6 +81,10 @@ class _ClaudePaneState extends State<ClaudePane> {
   String? _error;
   String _statusLine = 'starting…';
 
+  /// One-shot fork source: seeds the first bind, then cleared so /clear,
+  /// /resume, and respawns operate on this pane's own session (T-375).
+  late String? _forkSource = widget.forkSourceId;
+
   bool _spawned = false;
 
   /// Per-session composer draft (text + caret), held here so an unsent
@@ -272,7 +276,7 @@ class _ClaudePaneState extends State<ClaudePane> {
     }
 
     final ManagedSession managed;
-    final forkSource = widget.forkSourceId;
+    final forkSource = _forkSource;
     if (forkSource != null) {
       // Fork pane: branch source session into a new clide-managed session.
       // The clide-internal id is a fresh UUID; the real claude session id is
@@ -286,6 +290,10 @@ class _ClaudePaneState extends State<ClaudePane> {
         if (mounted) setState(() => _error = 'Could not start fork: $e');
         return;
       }
+      // One-shot: the fork source seeds only the FIRST bind. Leaving it set
+      // made /clear re-fork the original conversation instead of clearing —
+      // every later respawn must operate on this pane's own session (T-375).
+      _forkSource = null;
       if (!mounted) return;
       setState(() => _statusLine = 'fork of $forkSource');
     } else {

test/builtin/claude/claude_pane_test.dart

@@ -52,15 +52,18 @@ void main() {
   late ClaudeSessionOrchestrator orch;
   late String root;
   final created = <_FakeProc>[];
+  final spawnArgs = <List<String>>[];
 
   setUp(() async {
     f = await KernelFixture.create();
     created.clear();
+    spawnArgs.clear();
     root = '/repo-a';
     orch = ClaudeSessionOrchestrator(
       processFactory: ({required sessionArgs, required cwd, env}) async {
         final p = _FakeProc();
         created.add(p);
+        spawnArgs.add(sessionArgs);
         return p;
       },
     );
@@ -175,6 +178,20 @@ void main() {
     expect(orch.byId('primary')!.sessionId, id);
   });
 
+  testWidgets('/clear in a fork pane clears instead of re-forking (T-375)', (tester) async {
+    await mount(tester, const ClaudePane(showChrome: false, isPrimary: false, secondaryIndex: 1, forkSourceId: 'source-session-uuid'));
+    // First bind forks from the source.
+    expect(spawnArgs.single, containsAll(['--fork-session', 'source-session-uuid']));
+
+    await act(tester, () => composer(tester).onSubmit('/clear'));
+
+    // The respawn must NOT fork the original again — the fork source is a
+    // one-shot spawn parameter consumed by the first bind.
+    expect(spawnArgs, hasLength(2));
+    expect(spawnArgs.last, isNot(contains('--fork-session')));
+    expect(spawnArgs.last, isNot(contains('source-session-uuid')));
+  });
+
   testWidgets('/fork delegates to the onFork callback with the session id', (tester) async {
     String? forkedWith;
     await mount(tester, ClaudePane(showChrome: false, onFork: (sid) => forkedWith = sid));