From 8c55d224c5c62288b75bd9108b975f61b371e9e3 Mon Sep 17 00:00:00 2001
From: qiyi71w <1411348064@qq.com>
Date: Wed, 19 Aug 2026 02:32:27 +0800
Subject: [PATCH] fix(session): scope in-flight title latch to session id

A boolean latch survived /new and unnamed session switches, so the
replacement session skipped titling and could inherit the previous
skill's title. Bind the latch and the apply check to the originating
session id.
---
 .../coding-agent/src/session/agent-session.ts | 21 ++++---
 ...t-session-title-generation-dispose.test.ts | 61 +++++++++++++++++++
 2 files changed, 75 insertions(+), 7 deletions(-)

diff --git a/packages/coding-agent/src/session/agent-session.ts b/packages/coding-agent/src/session/agent-session.ts
index 788d3f41b..1883c8e2e 100644
--- a/packages/coding-agent/src/session/agent-session.ts
+++ b/packages/coding-agent/src/session/agent-session.ts
@@ -535,7 +535,7 @@ export class AgentSession {
 	 *  the session cwd changes. */
 	#titleSystemPrompt: string | undefined;
 	#titleGenerationStart: (() => void) | undefined;
-	#titleGenerationInFlight = false;
+	#titleGenerationInFlightFor: string | undefined;
 	#titleGenerationAbortController = new AbortController();
 	#toolChoiceQueue = new ToolChoiceQueue();
 
@@ -6550,26 +6550,31 @@ export class AgentSession {
 			this.#extensionRunner?.getCommand(
 				extensionCommandSpace === -1 ? firstMessage.slice(1) : firstMessage.slice(1, extensionCommandSpace),
 			) !== undefined;
+		const sessionId = this.sessionManager.getSessionId();
 		if (
 			isLocalExtensionCommand ||
 			this.sessionName ||
-			this.#titleGenerationInFlight ||
+			this.#titleGenerationInFlightFor === sessionId ||
 			$env.PI_NO_TITLE ||
 			isLowSignalTitleInput(firstMessage)
 		) {
 			return;
 		}
-		this.#titleGenerationInFlight = true;
+		this.#titleGenerationInFlightFor = sessionId;
 		try {
 			(onStart ?? this.#titleGenerationStart)?.();
 		} catch (error) {
-			this.#titleGenerationInFlight = false;
+			if (this.#titleGenerationInFlightFor === sessionId) {
+				this.#titleGenerationInFlightFor = undefined;
+			}
 			throw error;
 		}
 		this.generateTitle(firstMessage)
 			.then(async title => {
-				// Re-check after generation so concurrent attempts cannot replace
-				// the first title that completed.
+				// Re-check after generation so a later completion cannot replace
+				// the first title, and a request from a replaced session cannot
+				// name the current one.
+				if (this.sessionManager.getSessionId() !== sessionId) return;
 				if (title && !this.sessionName) {
 					await this.sessionManager.setSessionName(title, "auto");
 				}
@@ -6582,7 +6587,9 @@ export class AgentSession {
 				});
 			})
 			.finally(() => {
-				this.#titleGenerationInFlight = false;
+				if (this.#titleGenerationInFlightFor === sessionId) {
+					this.#titleGenerationInFlightFor = undefined;
+				}
 			});
 	}
 
diff --git a/packages/coding-agent/test/agent-session-title-generation-dispose.test.ts b/packages/coding-agent/test/agent-session-title-generation-dispose.test.ts
index eb9b87275..f425c62fc 100644
--- a/packages/coding-agent/test/agent-session-title-generation-dispose.test.ts
+++ b/packages/coding-agent/test/agent-session-title-generation-dispose.test.ts
@@ -106,4 +106,65 @@ describe("AgentSession title generation disposal", () => {
 		response.resolve(createAssistantMessage("<title>manual llm</title>"));
 		await response.promise;
 	});
+
+	it("lets a replacement session title itself and ignores the previous request", async () => {
+		authStorage = await AuthStorage.create(":memory:");
+		authStorage.setRuntimeApiKey("anthropic", "test-key");
+		const model = getBundledModel("anthropic", "claude-sonnet-4-5");
+		if (!model) throw new Error("Expected claude-sonnet-4-5 model to exist");
+
+		const settings = Settings.isolated({
+			"compaction.enabled": false,
+			"providers.tinyModel": "online",
+		});
+		settings.overrideModelRoles({ smol: `${model.provider}/${model.id}` });
+		const agent = new Agent({
+			getApiKey: () => "test-key",
+			initialState: { model, systemPrompt: ["Test"], tools: [], messages: [] },
+			streamFn: createMockModel({ responses: [{ content: ["Done"] }] }).stream,
+		});
+		session = new AgentSession({
+			agent,
+			sessionManager: SessionManager.inMemory(),
+			settings,
+			modelRegistry: new ModelRegistry(authStorage),
+		});
+		const firstStarted = Promise.withResolvers<void>();
+		const secondStarted = Promise.withResolvers<void>();
+		const firstResponse = Promise.withResolvers<ai.AssistantMessage>();
+		const secondResponse = Promise.withResolvers<ai.AssistantMessage>();
+		let titleCalls = 0;
+		const completeSimple = vi.spyOn(ai, "completeSimple").mockImplementation(() => {
+			titleCalls += 1;
+			if (titleCalls === 1) {
+				firstStarted.resolve();
+				return firstResponse.promise;
+			}
+			secondStarted.resolve();
+			return secondResponse.promise;
+		});
+		const generateTitle = vi.spyOn(session, "generateTitle");
+		const setSessionName = vi.spyOn(session.sessionManager, "setSessionName");
+		const firstSessionId = session.sessionManager.getSessionId();
+
+		session.maybeStartTitleGeneration("/skill:implement issues/07-manual-llm.md");
+		await firstStarted.promise;
+		expect(await session.newSession()).toBe(true);
+		expect(session.sessionManager.getSessionId()).not.toBe(firstSessionId);
+
+		session.maybeStartTitleGeneration("name the replacement session");
+		await secondStarted.promise;
+		expect(completeSimple).toHaveBeenCalledTimes(2);
+
+		firstResponse.resolve(createAssistantMessage("<title>old skill</title>"));
+		expect(await generateTitle.mock.results[0]?.value).toBe("old skill");
+		await Promise.resolve();
+		expect(setSessionName).not.toHaveBeenCalled();
+		expect(session.sessionName).toBeUndefined();
+
+		secondResponse.resolve(createAssistantMessage("<title>replacement session</title>"));
+		expect(await generateTitle.mock.results[1]?.value).toBe("replacement session");
+		await setSessionName.mock.results[0]?.value;
+		expect(session.sessionName).toBe("replacement session");
+	});
 });