From fcbe3a511f3018669c92cd5da963c0a37c55f691 Mon Sep 17 00:00:00 2001
From: ultrahighsuper <alaricmercer509@outlook.com>
Date: Fri, 17 Jul 2026 01:45:33 +0900
Subject: [PATCH] fix(github): reject a malformed three-segment repoFullName in
 comments.ts
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

`createOrUpdateIssueCommentWithMarker` validated `repoFullName` with
`const [owner, repo] = repoFullName.split("/")` + a truthiness check, so
"owner/repo/extra" passed: the destructure silently dropped the extra segment
and the GitHub call was issued against "owner/repo" — a repo the caller never
specified.

Add the missing `parts.length !== 2` segment-count check inline, matching the
guard already present in parseRepoFullName (assignees.ts / labels.ts). No-slash
and empty-segment inputs are still rejected exactly as before; whitespace
handling is intentionally left unchanged (a separate issue covers that in a
different file).

Extends test/unit/github-comments.test.ts with a case asserting
"owner/repo/extra" is rejected via createOrUpdatePrIntelligenceComment,
mirroring the existing precedent in github-assignees.test.ts.

Closes #6612
---
 src/github/comments.ts            | 9 +++++++--
 test/unit/github-comments.test.ts | 8 ++++++++
 2 files changed, 15 insertions(+), 2 deletions(-)

diff --git a/src/github/comments.ts b/src/github/comments.ts
index 779637c4cf..95c22d3441 100644
--- a/src/github/comments.ts
+++ b/src/github/comments.ts
@@ -50,8 +50,13 @@ async function createOrUpdateIssueCommentWithMarker(
   marker: string,
   options: { createIfMissing?: boolean | undefined; mode?: AgentActionMode } = {},
 ): Promise<{ id: number; html_url?: string } | null> {
-  const [owner, repo] = repoFullName.split("/");
-  if (!owner || !repo) throw new Error(`Invalid repository full name: ${repoFullName}`);
+  const parts = repoFullName.split("/");
+  const owner = parts[0];
+  const repo = parts[1];
+  // Reject anything that is not exactly two non-empty segments -- "owner/repo/extra" would otherwise pass
+  // (the destructure silently drops the extra segment), issuing a call against a repo the caller never
+  // specified. Matches the segment-count guard in parseRepoFullName (assignees.ts / labels.ts).
+  if (parts.length !== 2 || !owner || !repo) throw new Error(`Invalid repository full name: ${repoFullName}`);
 
   return await withInstallationTokenRetry(env, installationId, async (token) => {
     // Non-live mode suppresses the comment create/update writes; the GET marker-search probe below still runs.
diff --git a/test/unit/github-comments.test.ts b/test/unit/github-comments.test.ts
index dc98b246de..21b7d99afd 100644
--- a/test/unit/github-comments.test.ts
+++ b/test/unit/github-comments.test.ts
@@ -379,6 +379,14 @@ describe("GitHub PR intelligence comments", () => {
   it("rejects invalid repository names before calling GitHub", async () => {
     await expect(createOrUpdatePrIntelligenceComment(createTestEnv(), 123, "invalid", 12, "body")).rejects.toThrow(/Invalid repository full name/);
   });
+
+  it("rejects a malformed three-segment repository name instead of silently truncating it", async () => {
+    // "owner/repo/extra" splits into three segments; the extra one must be rejected, not dropped, so no
+    // GitHub call is ever made against the truncated "owner/repo".
+    await expect(createOrUpdatePrIntelligenceComment(createTestEnv(), 123, "owner/repo/extra", 12, "body")).rejects.toThrow(
+      /Invalid repository full name/,
+    );
+  });
 });
 
 async function generatePrivateKeyPem(): Promise<string> {