Fix UTF-16-safe realtime context truncation

Alix-007 · Alix-007 · commit 7b5f6d8f9328 · 2026-07-07T12:39:56.000+08:00
diff --git a/extensions/voice-call/src/realtime-agent-context.test.ts b/extensions/voice-call/src/realtime-agent-context.test.ts
@@ -93,4 +93,29 @@ describe("buildRealtimeVoiceInstructions", () => {
     expect(instructions).toContain("### IDENTITY.md");
     expect(instructions).not.toContain("do not include");
   });
+
+  it("truncates injected context without splitting UTF-16 surrogate pairs", async () => {
+    const agentId = `abc\uD83D\uDE80tail`;
+    const config = createConfig({
+      agentContext: {
+        enabled: true,
+        maxChars: "OpenClaw agent voice context:\n\n- Agent id: abc".length + 33,
+        includeIdentity: false,
+        includeWorkspaceFiles: false,
+        files: [],
+      },
+    });
+    config.agentId = agentId;
+
+    const instructions = await buildRealtimeVoiceInstructions({
+      baseInstructions: "Base voice instructions.",
+      config,
+      coreConfig: { agents: { list: [{ id: agentId }] } } as CoreConfig,
+      agentRuntime: createAgentRuntime(await createWorkspace()),
+    });
+
+    expect(instructions).toContain("- Agent id: abc\n[truncated]");
+    expect(instructions).not.toContain("\uD83D");
+    expect(instructions).not.toContain("\uDE80");
+  });
 });
diff --git a/extensions/voice-call/src/realtime-agent-context.ts b/extensions/voice-call/src/realtime-agent-context.ts
@@ -3,6 +3,7 @@ import type { OpenClawConfig } from "openclaw/plugin-sdk/config-contracts";
 import { buildRealtimeVoiceAgentConsultPolicyInstructions } from "openclaw/plugin-sdk/realtime-voice";
 import { root } from "openclaw/plugin-sdk/security-runtime";
 import { normalizeOptionalString as normalizeString } from "openclaw/plugin-sdk/string-coerce-runtime";
+import { truncateUtf16Safe } from "openclaw/plugin-sdk/text-utility-runtime";
 import type { VoiceCallConfig } from "./config.js";
 import type { CoreAgentDeps, CoreConfig } from "./core-bridge.js";
 
@@ -22,7 +23,7 @@ function limitText(text: string, maxChars: number): string {
   if (text.length <= maxChars) {
     return text;
   }
-  return `${text.slice(0, Math.max(0, maxChars - 32)).trimEnd()}\n[truncated]`;
+  return `${truncateUtf16Safe(text, Math.max(0, maxChars - 32)).trimEnd()}\n[truncated]`;
 }
 
 /** Read configured workspace context files through the safe workspace root. */

Original file line number	Diff line number	Diff line change
`@@ -3,6 +3,7 @@ import type { OpenClawConfig } from "openclaw/plugin-sdk/config-contracts";`
`3`	`3`	`import { buildRealtimeVoiceAgentConsultPolicyInstructions } from "openclaw/plugin-sdk/realtime-voice";`
`4`	`4`	`import { root } from "openclaw/plugin-sdk/security-runtime";`
`5`	`5`	`import { normalizeOptionalString as normalizeString } from "openclaw/plugin-sdk/string-coerce-runtime";`
	`6`	`+import { truncateUtf16Safe } from "openclaw/plugin-sdk/text-utility-runtime";`
`6`	`7`	`import type { VoiceCallConfig } from "./config.js";`
`7`	`8`	`import type { CoreAgentDeps, CoreConfig } from "./core-bridge.js";`
`8`	`9`
`@@ -22,7 +23,7 @@ function limitText(text: string, maxChars: number): string {`
`22`	`23`	`if (text.length <= maxChars) {`
`23`	`24`	`return text;`
`24`	`25`	`}`
`25`		- return `${text.slice(0, Math.max(0, maxChars - 32)).trimEnd()}\n[truncated]`;
	`26`	+ return `${truncateUtf16Safe(text, Math.max(0, maxChars - 32)).trimEnd()}\n[truncated]`;
`26`	`27`	`}`
`27`	`28`
`28`	`29`	`/** Read configured workspace context files through the safe workspace root. */`