From d5fc7e6ebf9af050081fc4c6e18b9079cfaa5cdc Mon Sep 17 00:00:00 2001
From: morluto <76467478+morluto@users.noreply.github.com>
Date: Sun, 18 Oct 2026 09:53:59 +0800
Subject: [PATCH] fix(rizin): preserve output whitespace before completion
 markers

Adapt #4044 at the shared normal/interrupted frame owner. Preserve the decoded prefix before byte-budget accounting and cover MCP delivery across framing and UTF-8 boundaries. Refs #4016.

Co-authored-by: Xander-AJ <133286098+Xander-AJ@users.noreply.github.com>
---
 src/rizin/RizinDebugSessionManager.ts         |   2 +-
 .../mcp/rizinOutputPreservation.test.ts       | 119 ++++++++++++++++++
 2 files changed, 120 insertions(+), 1 deletion(-)
 create mode 100644 tests/boundary/mcp/rizinOutputPreservation.test.ts

diff --git a/src/rizin/RizinDebugSessionManager.ts b/src/rizin/RizinDebugSessionManager.ts
index 47c120b607..a8bc548946 100644
--- a/src/rizin/RizinDebugSessionManager.ts
+++ b/src/rizin/RizinDebugSessionManager.ts
@@ -1437,7 +1437,7 @@ const waitForCommandFrames = async (
     outputTruncated ||= frame.truncated;
     const markerIndex = frame.text.indexOf(marker);
     const text =
-      markerIndex < 0 ? frame.text : frame.text.slice(0, markerIndex).trimEnd();
+      markerIndex < 0 ? frame.text : frame.text.slice(0, markerIndex);
     if (markerIndex >= 0 && text.length === 0) return true;
     const separatorBytes = output.length > 0 ? 1 : 0;
     const remaining = maxCommandOutputBytes - outputBytes - separatorBytes;
diff --git a/tests/boundary/mcp/rizinOutputPreservation.test.ts b/tests/boundary/mcp/rizinOutputPreservation.test.ts
new file mode 100644
index 0000000000..2c09f3e9ef
--- /dev/null
+++ b/tests/boundary/mcp/rizinOutputPreservation.test.ts
@@ -0,0 +1,119 @@
+import { Client, InMemoryTransport } from "@modelcontextprotocol/client";
+import { McpServer } from "@modelcontextprotocol/server";
+import { expect, it } from "vitest";
+
+import { registerRizinDebugTools } from "../../../src/server/registerRizinDebugTools.js";
+import { createToolResultDelivery } from "../../../src/server/toolResult.js";
+import { toolContract } from "../../../src/contracts/toolContracts.js";
+import { silentLogger } from "../../../src/logger.js";
+import { createInjectedProcess } from "../providers/RizinDebugSessionCoverage.fixtures.js";
+import {
+  createRizinTestManager,
+  rizinTestInferiorTty,
+} from "../providers/RizinTestInferiorTty.js";
+
+const test = it.skipIf(process.platform === "win32");
+
+const observe = async (
+  prefix: string,
+  framing: "coalesced" | "separate" | "split-transport",
+  maximum?: number,
+) => {
+  const injected = createInjectedProcess({
+    onWrite: (text, control) => {
+      const marker = /!echo (.+)\n/u.exec(text)?.[1];
+      if (marker === undefined) return;
+      setImmediate(() => {
+        if (framing === "separate") control.output(`${prefix}\0${marker}\n\0`);
+        else if (framing === "split-transport") {
+          const bytes = Buffer.from(`${prefix}${marker}\n\0`);
+          const split = Math.max(1, Buffer.byteLength(prefix) - 1);
+          control.output(bytes.subarray(0, split));
+          control.output(bytes.subarray(split));
+        } else control.output(`${prefix}${marker}\n\0`);
+      });
+    },
+  });
+  const manager = createRizinTestManager(
+    {},
+    {
+      spawnProcess: injected.spawnProcess,
+      frameTimeoutMs: 100,
+      ...(maximum === undefined ? {} : { maxCommandOutputBytes: maximum }),
+    },
+  );
+  const server = new McpServer({ name: "rizin-output-test", version: "1" });
+  registerRizinDebugTools(
+    server,
+    manager,
+    silentLogger,
+    createToolResultDelivery(undefined),
+  );
+  const client = new Client({ name: "rizin-output-test", version: "1" });
+  const [clientTransport, serverTransport] =
+    InMemoryTransport.createLinkedPair();
+  try {
+    await server.connect(serverTransport);
+    await client.connect(clientTransport);
+    const startReply = await client.callTool({
+      name: "start_rizin_debug_session",
+      arguments: {
+        path: "fixture.bin",
+        inferior_tty: await rizinTestInferiorTty(),
+      },
+    });
+    expect(startReply.isError).not.toBe(true);
+    const started = toolContract(
+      "start_rizin_debug_session",
+    ).outputSchema.parse(startReply.structuredContent);
+    const reply = await client.callTool({
+      name: "rizin_debug_command",
+      arguments: { session_id: started.session_id, command: "dr" },
+    });
+    expect(reply.isError).not.toBe(true);
+    return toolContract("rizin_debug_command").outputSchema.parse(
+      reply.structuredContent,
+    );
+  } finally {
+    injected.control.exit();
+    await client.close();
+    await server.close();
+    await manager.closeAll();
+  }
+};
+
+test.each(
+  ["value  \n", " \t\r\n", "Ω雪\t\r\n", "", "😀"].flatMap((prefix) =>
+    (["coalesced", "separate", "split-transport"] as const).map((framing) => ({
+      prefix,
+      framing,
+    })),
+  ),
+)(
+  "preserves output %j across $framing framing",
+  async ({ prefix, framing }) => {
+    const evidence = await observe(prefix, framing);
+    const expected = {
+      output: prefix,
+      completion_status: "complete",
+      output_truncated: false,
+    };
+    expect(evidence.normalized_result).toMatchObject(expected);
+    expect(evidence.raw_result).toMatchObject(expected);
+  },
+);
+
+test.each([7, 8])(
+  "counts trailing whitespace in the exact %s-byte budget",
+  async (maximum) => {
+    const evidence = await observe("value  \n", "coalesced", maximum);
+    const truncated = maximum < 8;
+    const expected = {
+      output: truncated ? "value  " : "value  \n",
+      output_truncated: truncated,
+      completion_status: truncated ? "unknown" : "complete",
+    };
+    expect(evidence.normalized_result).toMatchObject(expected);
+    expect(evidence.raw_result).toMatchObject(expected);
+  },
+);