fix(media): keep input_file text truncation UTF-16 safe

mushuiyu886 · mushuiyu886 · commit 30421aff0ca2 · 2026-07-09T17:28:50.000+08:00
diff --git a/src/gateway/openresponses-http.test.ts b/src/gateway/openresponses-http.test.ts
@@ -1891,6 +1891,43 @@ describe("OpenResponses HTTP API (e2e)", () => {
     await ensureResponseConsumed(res);
   });
 
+  it("keeps base64 input_file text truncation UTF-16 safe", async () => {
+    const port = enabledPort;
+    const text = `${"a".repeat(59_999)}😀tail`;
+    agentCommand.mockClear();
+    agentCommand.mockResolvedValueOnce({ payloads: [{ text: "ok" }] } as never);
+
+    const res = await postResponses(port, {
+      model: "openclaw",
+      input: [
+        {
+          type: "message",
+          role: "user",
+          content: [
+            {
+              type: "input_file",
+              source: {
+                type: "base64",
+                media_type: "text/plain",
+                data: Buffer.from(text).toString("base64"),
+                filename: "emoji-boundary.txt",
+              },
+            },
+          ],
+        },
+      ],
+    });
+
+    expect(res.status).toBe(200);
+    expect(agentCommand).toHaveBeenCalledTimes(1);
+    const opts = firstAgentOpts();
+    const extraSystemPrompt = (opts as { extraSystemPrompt?: string }).extraSystemPrompt ?? "";
+    expect(extraSystemPrompt).toContain('<file name="emoji-boundary.txt">');
+    expect(extraSystemPrompt).not.toContain("😀");
+    expect(extraSystemPrompt).not.toMatch(/[\uD800-\uDBFF](?![\uDC00-\uDFFF])/u);
+    await ensureResponseConsumed(res);
+  });
+
   it("still rejects input with neither text nor image", async () => {
     const port = enabledPort;
     agentCommand.mockClear();
diff --git a/src/media/input-files.ts b/src/media/input-files.ts
@@ -6,6 +6,7 @@ import {
   normalizeOptionalLowercaseString,
   normalizeOptionalString,
 } from "@openclaw/normalization-core/string-coerce";
+import { truncateUtf16Safe } from "@openclaw/normalization-core/utf16-slice";
 import type { OpenClawConfig } from "../config/types.openclaw.js";
 import { readResponseWithLimit } from "../infra/http-body.js";
 import { fetchWithSsrFGuard } from "../infra/net/fetch-guard.js";
@@ -273,7 +274,7 @@ function clampText(text: string, maxChars: number): string {
   if (text.length <= maxChars) {
     return text;
   }
-  return text.slice(0, maxChars);
+  return truncateUtf16Safe(text, maxChars);
 }
 
 function withInputFileTimeout<T>(params: {
