test(frontmatter): Include too many dashes

Author: epage

tests/testsuite/script/rustc.rs

@@ -270,6 +270,14 @@ fn fence_mismatch_2() {
     assert_failure(fixture_path, assertion_path);
 }
 
+#[cargo_test(nightly, reason = "-Zscript is unstable")]
+#[rustfmt::skip]  // code-generated
+fn fence_too_many_dashes() {
+    let fixture_path = "tests/testsuite/script/rustc_fixtures/fence-too-many-dashes.rs";
+    let assertion_path = "tests/testsuite/script/rustc_fixtures/fence-too-many-dashes.stdout";
+    assert_success(fixture_path, assertion_path);
+}
+
 #[cargo_test(nightly, reason = "-Zscript is unstable")]
 #[rustfmt::skip]  // code-generated
 fn fence_unclosed_1() {

tests/testsuite/script/rustc_fixtures/fence-too-many-dashes.rs

@@ -0,0 +1,9 @@
+----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
+[dependencies]
+----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
+
+#![feature(frontmatter)]
+
+// check that we limit fence lengths
+
+fn main() {}

tests/testsuite/script/rustc_fixtures/fence-too-many-dashes.stdout

@@ -0,0 +1,41 @@
+{
+  "authors": [],
+  "categories": [],
+  "default_run": null,
+  "dependencies": [],
+  "description": null,
+  "documentation": null,
+  "edition": "2024",
+  "features": {},
+  "homepage": null,
+  "id": "path+[ROOTURL]/foo/script#0.0.0",
+  "keywords": [],
+  "license": null,
+  "license_file": null,
+  "links": null,
+  "manifest_path": "[ROOT]/foo/script",
+  "metadata": null,
+  "name": "script",
+  "publish": [],
+  "readme": null,
+  "repository": null,
+  "rust_version": null,
+  "source": null,
+  "targets": [
+    {
+      "crate_types": [
+        "bin"
+      ],
+      "doc": true,
+      "doctest": false,
+      "edition": "2024",
+      "kind": [
+        "bin"
+      ],
+      "name": "script",
+      "src_path": "[ROOT]/foo/script",
+      "test": true
+    }
+  ],
+  "version": "0.0.0"
+}