fix(chat): tool titles corrupt boundary emoji in long inputs (#104464)

zhangguiping-xydt · steipete · web-flow · commit 04037e35c03e · 2026-07-11T10:45:04.000-07:00
* fix(chat): tool titles corrupt boundary emoji in long inputs

* test(chat): simplify UTF-16 title boundary coverage

* test(chat): satisfy title boundary lint

---------

Co-authored-by: Peter Steinberger &lt;steipete@gmail.com&gt;
diff --git a/src/gateway/chat-tool-titles.test.ts b/src/gateway/chat-tool-titles.test.ts
@@ -133,6 +133,25 @@ describe("generateToolCallTitles", () => {
     expect(content).not.toContain(token.slice(0, 12));
   });
 
+  it("keeps bounded tool input valid before utility-model prompt construction", async () => {
+    mockPreparedModel();
+    mockCompletionTitles({ "0": "Inspected boundary input" });
+
+    await generateToolCallTitles({
+      cfg: {} satisfies OpenClawConfig,
+      agentId: AGENT_ID,
+      items: [{ id: "item-1", name: "bash", input: `${"a".repeat(1_999)}😀tail` }],
+    });
+
+    const call = completeWithPreparedSimpleCompletionModel.mock.calls[0]?.[0] as {
+      context: { messages: Array<{ content: string }> };
+    };
+    const promptPayload = JSON.parse(call.context.messages[0]?.content ?? "{}") as {
+      items?: Array<{ input?: string }>;
+    };
+    expect(promptPayload.items?.[0]?.input).toBe("a".repeat(1_999));
+  });
+
   it("serves repeated items from the SQLite cache without a second completion", async () => {
     mockPreparedModel();
     mockCompletionTitles({ "0": "Checked repo status" });
diff --git a/src/gateway/chat-tool-titles.ts b/src/gateway/chat-tool-titles.ts
@@ -74,7 +74,7 @@ function normalizeItems(items: readonly ToolTitleRequestItem[]): ToolTitleReques
     // secret egress path. Redaction runs on the full schema-bounded input and
     // only then truncates — slicing first could bisect a secret so its
     // fragment no longer matches any redaction pattern.
-    const input = redactToolPayloadText(item.input).slice(0, TOOL_TITLE_INPUT_MAX_CHARS);
+    const input = truncateUtf16Safe(redactToolPayloadText(item.input), TOOL_TITLE_INPUT_MAX_CHARS);
     if (!id || !name || !input.trim() || seen.has(id)) {
       continue;
     }
diff --git a/ui/src/pages/chat/tool-titles.test.ts b/ui/src/pages/chat/tool-titles.test.ts
@@ -52,6 +52,19 @@ describe("resolveToolTitleRequest", () => {
 
     expect(first?.key).toBe(second?.key);
   });
+
+  it.each([
+    ["command", "bash", { command: `${"a".repeat(1_999)}😀tail` }, "a".repeat(1_999)],
+    ["string args", "mcp__linear__create_issue", `${"a".repeat(1_999)}😀tail`, "a".repeat(1_999)],
+    [
+      "serialized object args",
+      "mcp__linear__create_issue",
+      { value: `${"a".repeat(1_989)}😀tail` },
+      '{"value":"' + "a".repeat(1_989),
+    ],
+  ])("keeps bounded %s on a valid UTF-16 boundary", (_label, name, args, expected) => {
+    expect(resolveToolTitleRequest(name, args)?.input).toBe(expected);
+  });
 });
 
 describe("getToolCallTitle", () => {
diff --git a/ui/src/pages/chat/tool-titles.ts b/ui/src/pages/chat/tool-titles.ts
@@ -8,6 +8,7 @@
  * labels.
  */
 
+import { truncateUtf16Safe } from "@openclaw/normalization-core/utf16-slice";
 import type { GatewayBrowserClient } from "../../api/gateway.ts";
 import { resolveToolCallKind, unwrapShellWrapperCommand } from "../../lib/chat/tool-call-view.ts";
 
@@ -68,11 +69,11 @@ function serializeArgs(args: unknown): string | null {
     return null;
   }
   if (typeof args === "string") {
-    return args.slice(0, MAX_TITLE_INPUT_CHARS);
+    return truncateUtf16Safe(args, MAX_TITLE_INPUT_CHARS);
   }
   try {
     const encoded = JSON.stringify(args);
-    return typeof encoded === "string" ? encoded.slice(0, MAX_TITLE_INPUT_CHARS) : null;
+    return typeof encoded === "string" ? truncateUtf16Safe(encoded, MAX_TITLE_INPUT_CHARS) : null;
   } catch {
     return null;
   }
@@ -98,7 +99,7 @@ export function resolveToolTitleRequest(
     if (command.length < MIN_COMMAND_CHARS_FOR_TITLE) {
       return null;
     }
-    const input = command.slice(0, MAX_TITLE_INPUT_CHARS);
+    const input = truncateUtf16Safe(command, MAX_TITLE_INPUT_CHARS);
     return { key: digest("command", input), input };
   }
   if (kind !== "generic") {

Original file line number	Diff line number	Diff line change
`@@ -74,7 +74,7 @@ function normalizeItems(items: readonly ToolTitleRequestItem[]): ToolTitleReques`
`74`	`74`	`// secret egress path. Redaction runs on the full schema-bounded input and`
`75`	`75`	`// only then truncates — slicing first could bisect a secret so its`
`76`	`76`	`// fragment no longer matches any redaction pattern.`
`77`		`- const input = redactToolPayloadText(item.input).slice(0, TOOL_TITLE_INPUT_MAX_CHARS);`
	`77`	`+ const input = truncateUtf16Safe(redactToolPayloadText(item.input), TOOL_TITLE_INPUT_MAX_CHARS);`
`78`	`78`	`if (!id \|\| !name \|\| !input.trim() \|\| seen.has(id)) {`
`79`	`79`	`continue;`
`80`	`80`	`}`
Original file line number	Diff line number	Diff line change
`@@ -8,6 +8,7 @@`
`8`	`8`	`* labels.`
`9`	`9`	`*/`
`10`	`10`
	`11`	`+import { truncateUtf16Safe } from "@openclaw/normalization-core/utf16-slice";`
`11`	`12`	`import type { GatewayBrowserClient } from "../../api/gateway.ts";`
`12`	`13`	`import { resolveToolCallKind, unwrapShellWrapperCommand } from "../../lib/chat/tool-call-view.ts";`
`13`	`14`
`@@ -68,11 +69,11 @@ function serializeArgs(args: unknown): string \| null {`
`68`	`69`	`return null;`
`69`	`70`	`}`
`70`	`71`	`if (typeof args === "string") {`
`71`		`- return args.slice(0, MAX_TITLE_INPUT_CHARS);`
	`72`	`+ return truncateUtf16Safe(args, MAX_TITLE_INPUT_CHARS);`
`72`	`73`	`}`
`73`	`74`	`try {`
`74`	`75`	`const encoded = JSON.stringify(args);`
`75`		`- return typeof encoded === "string" ? encoded.slice(0, MAX_TITLE_INPUT_CHARS) : null;`
	`76`	`+ return typeof encoded === "string" ? truncateUtf16Safe(encoded, MAX_TITLE_INPUT_CHARS) : null;`
`76`	`77`	`} catch {`
`77`	`78`	`return null;`
`78`	`79`	`}`
`@@ -98,7 +99,7 @@ export function resolveToolTitleRequest(`
`98`	`99`	`if (command.length < MIN_COMMAND_CHARS_FOR_TITLE) {`
`99`	`100`	`return null;`
`100`	`101`	`}`
`101`		`- const input = command.slice(0, MAX_TITLE_INPUT_CHARS);`
	`102`	`+ const input = truncateUtf16Safe(command, MAX_TITLE_INPUT_CHARS);`
`102`	`103`	`return { key: digest("command", input), input };`
`103`	`104`	`}`
`104`	`105`	`if (kind !== "generic") {`