Reseed the crash handle when rotation repoints the session

Author: TheGreatAxios

src/tui/runner/exit.ts

@@ -591,11 +591,25 @@ export async function createRunLifecycle(
           "session-rotation",
         );
         state.sessionId = generateSessionId();
-        // Repointed, not cleared: the process lives on, so the crash handler
-        // must keep finding this handle and close out the *new* session.
-        services.activeRunHandle.sessionId = state.sessionId;
         state.startedAt = Date.now();
         state.runTaskTitle = state.config.task;
+        const rotatedBundle = services.buildSessionSources();
+        // Repointed, not cleared: the process lives on, so the crash handler
+        // must keep finding this handle and close out the *new* session. The
+        // fields it copies reseed with the repoint — a crash inside
+        // initSessionDir/buildAgent below would otherwise stamp the outgoing
+        // session's turnsUsed (and task, startedAt, model) onto a session
+        // that has run zero turns.
+        services.activeRunHandle.sessionId = state.sessionId;
+        syncRunStateHandle(services.activeRunHandle, {
+          turnsUsed: 0,
+          task:
+            state.runTaskTitle.trim().length > 0
+              ? state.runTaskTitle.trim()
+              : "(conversation)",
+          startedAt: state.startedAt,
+          model: `${rotatedBundle.selected.id}:${rotatedBundle.selected.model}`,
+        });
         services.emitter.emit(
           "session.title",
           state.runTaskTitle.trim().length > 0
@@ -604,7 +618,6 @@ export async function createRunLifecycle(
         );
         state.workdir = sessionContextDir(state.config.cwd, state.sessionId);
         await initSessionDir(state.config.cwd, state.sessionId);
-        const rotatedBundle = services.buildSessionSources();
         state.liveSources = rotatedBundle.sources;
         state.liveDefaultSource = rotatedBundle.defaultSource;
         state.liveSource = rotatedBundle.selected;

tests/fixtures/crash-run/simulate-crash.ts

@@ -7,6 +7,7 @@ import { installCrashHandlers } from "../../../src/index.js";
 import {
   setActiveRun,
   setTestWriteGate,
+  syncRunStateHandle,
 } from "../../../src/session/active-run.js";
 import { sessionDir } from "../../../src/session/index.js";
 import { finalizeRunState, saveState } from "../../../src/session/state.js";
@@ -70,6 +71,15 @@ if (rotatedSessionId !== undefined) {
     await saveState(cwd, sessionId, rotationState);
   }
   activeRunHandle.sessionId = rotatedSessionId;
+  // Matches runner.ts reseeding the handle's snapshot fields at repoint: the
+  // new session has run zero turns, so a crash before its first persist must
+  // carry 0, not the outgoing session's count.
+  syncRunStateHandle(activeRunHandle, {
+    turnsUsed: 0,
+    task,
+    startedAt,
+    model,
+  });
   activeSessionId = rotatedSessionId;
 }
 

tests/integration/crash-finalize.test.ts

@@ -98,6 +98,7 @@ describe("integration — crash finalizes run.json", () => {
         readFileSync(outgoingRunJsonPath, "utf8"),
       ) as RunState;
       expect(outgoingState.status).toBe("done");
+      expect(outgoingState.turnsUsed).toBe(3);
 
       const rotatedRunJsonPath = join(stdout.trim(), "run.json");
       const rotatedState = JSON.parse(
@@ -109,6 +110,7 @@ describe("integration — crash finalizes run.json", () => {
       expect(rotatedState.status).toBe("crashed");
       expect(rotatedState.finishedAt).toBeGreaterThan(0);
       expect(rotatedState.error).toContain("simulated crash");
+      expect(rotatedState.turnsUsed).toBe(0);
     } finally {
       rmSync(cwd, { recursive: true, force: true });
       rmSync(home, { recursive: true, force: true });