fix(core): bypass gray-matter content cache when parsing frontmatter (#51245)

packages/core/src/config/markdown.ts

@@ -2,10 +2,14 @@ export * as ConfigMarkdown from "./markdown.js"
 
 import matter from "gray-matter"
 export function parse(content: string) {
+  // Passing options bypasses gray-matter's module-global content cache, which
+  // it populates before parsing: a failed YAML parse poisons the entry and
+  // every later parse of the same content replays it without throwing, so the
+  // sanitize fallback below never runs. Upstream: jonschlinkert/gray-matter#166.
   try {
-    return matter(content)
+    return matter(content, {})
   } catch {
-    return matter(sanitize(content))
+    return matter(sanitize(content), {})
   }
 }
 

packages/core/test/config/markdown.test.ts

@@ -0,0 +1,35 @@
+import { describe, expect, test } from "bun:test"
+import { ConfigMarkdown } from "@opencode/core/config/markdown"
+
+const invalidYaml = `---
+description: Use when the user needs to crawl pages. Keywords: crawl, scrape
+---
+body`
+
+describe("ConfigMarkdown.parse", () => {
+  test("recovers unquoted-colon frontmatter via the sanitize fallback", () => {
+    const parsed = ConfigMarkdown.parse(invalidYaml)
+    expect(parsed.data.description).toBe("Use when the user needs to crawl pages. Keywords: crawl, scrape")
+    expect(parsed.content.trim()).toBe("body")
+  })
+
+  test("recovers the same content again after a previous failed parse", () => {
+    // gray-matter caches by content before parsing; a poisoned entry used to
+    // make every later parse of the same text return silently without data.
+    expect(() => ConfigMarkdown.parse("---\ndescription: [unclosed\n---\nbody")).toThrow()
+    const parsed = ConfigMarkdown.parse(invalidYaml)
+    expect(parsed.data.description).toBe("Use when the user needs to crawl pages. Keywords: crawl, scrape")
+  })
+
+  test("keeps throwing for the same unparseable content on every call", () => {
+    const input = "---\ndescription: [unclosed\n---\nbody"
+    expect(() => ConfigMarkdown.parse(input)).toThrow()
+    expect(() => ConfigMarkdown.parse(input)).toThrow()
+  })
+
+  test("parses plain content without frontmatter", () => {
+    const parsed = ConfigMarkdown.parse("just body")
+    expect(parsed.content).toBe("just body")
+    expect(parsed.data).toEqual({})
+  })
+})