fix(sse): escape backslash in ChatGPT-web citation link text (#6569) (#6944)

* fix(sse): escape backslash in ChatGPT-web citation link text (#6569)

markdownLinkText() escaped [ and ] but not the backslash itself, so a
citation label ending in (or containing) a backslash produced a broken
Markdown link — e.g. [Path C:\](url), where the trailing \ escapes the
closing bracket and consumes the link. Escape the backslash first, then
the brackets.

Clears the CodeQL js/incomplete-sanitization alerts at
open-sse/executors/chatgpt-web/citations.ts:52 (2 of the 9 new alerts
on the v3.8.47 release PR).

Regression guard: tests/unit/chatgpt-web-citations-escape.test.ts
(trailing backslash, backslash-before-bracket, bracket-only, plain).

* chore(changelog): add changelog.d fragment for #6944

Co-authored-by: diegosouzapw <8016841+diegosouzapw@users.noreply.github.com>

---------

Co-authored-by: brick30llc-ctrl <admin@brick30.com>
Co-authored-by: Diego Rodrigues de Sa e Souza <diegosouza.pw@gmail.com>
Co-authored-by: diegosouzapw <8016841+diegosouzapw@users.noreply.github.com>

changelog.d/fixes/6944-chatgpt-web-citation-backslash-escape.md

@@ -0,0 +1 @@
+- **fix(sse):** escape backslash before brackets in ChatGPT-web citation link text, preventing a citation label containing `\` from corrupting the generated Markdown link ([#6944](https://github.com/diegosouzapw/OmniRoute/pull/6944)) — thanks @brick30llc-ctrl

open-sse/executors/chatgpt-web/citations.ts

@@ -49,7 +49,15 @@ function asArray(value: unknown): unknown[] {
 }
 
 function markdownLinkText(value: string): string {
-  return value.replace(/\[/g, "\\[").replace(/\]/g, "\\]").replace(/\n/g, " ").trim();
+  // Escape the backslash first — otherwise a label ending in (or containing) a
+  // backslash leaks past the `[…]` escaping and breaks the generated link, e.g.
+  // `[Path C:\](url)` where the trailing `\` escapes the closing bracket.
+  return value
+    .replace(/\\/g, "\\\\")
+    .replace(/\[/g, "\\[")
+    .replace(/\]/g, "\\]")
+    .replace(/\n/g, " ")
+    .trim();
 }
 
 function markdownUrl(value: string): string {

tests/unit/chatgpt-web-citations-escape.test.ts

@@ -0,0 +1,50 @@
+// ChatGPT-web citation link-text escaping (CodeQL js/incomplete-sanitization,
+// PR #6569 release-blocker).
+//
+// `markdownLinkText()` builds the `[text]` half of a Markdown link from an
+// untrusted citation label. It escaped `[` and `]` but NOT the backslash
+// itself, so a label ending in (or containing) a backslash produced a broken
+// link: e.g. `[Path C:\](url)` — the trailing `\` escapes the closing `]`,
+// consuming the link's bracket. The escape character must be escaped first.
+
+import test from "node:test";
+import assert from "node:assert/strict";
+
+const { cleanChatGptText } = await import(
+  "../../open-sse/executors/chatgpt-web/citations.ts"
+);
+
+const S = ""; // marker start
+const SEP = ""; // marker separator
+const E = ""; // marker end
+
+// Build a raw `url` citation marker:  url  <label>  <url> 
+const urlMarker = (label: string, url: string) => `${S}url${SEP}${label}${SEP}${url}${E}`;
+
+test("markdownLinkText escapes a trailing backslash in the citation label", () => {
+  // Label ends in a backslash — without escaping, `[Path C:\](url)` breaks the link.
+  const text = `See ${urlMarker("Path C:\\", "https://example.com/docs")} here`;
+  const out = cleanChatGptText(text);
+  assert.equal(out, "See [Path C:\\\\](https://example.com/docs) here");
+  // The backslash must be doubled (escaped), never left bare before the `]`.
+  assert.doesNotMatch(out, /[^\\]\\\]/);
+});
+
+test("markdownLinkText escapes a backslash preceding a bracket (no bracket leak)", () => {
+  const text = urlMarker("a\\[b", "https://example.com");
+  const out = cleanChatGptText(text);
+  // `\` → `\\`, then `[` → `\[` : label renders as literal `a\[b`.
+  assert.equal(out, "[a\\\\\\[b](https://example.com)");
+});
+
+test("bracket-only labels keep their existing escaping (regression guard)", () => {
+  const text = urlMarker("a[b]c", "https://example.com");
+  const out = cleanChatGptText(text);
+  assert.equal(out, "[a\\[b\\]c](https://example.com)");
+});
+
+test("plain labels with no metacharacters pass through unchanged", () => {
+  const text = urlMarker("Plain Title", "https://example.com");
+  const out = cleanChatGptText(text);
+  assert.equal(out, "[Plain Title](https://example.com)");
+});