From b1d08275a9914b59bbad3cf5f80073b8365e9e67 Mon Sep 17 00:00:00 2001
From: Michael Howell <michael@notriddle.com>
Date: Thu, 20 Apr 2023 18:08:06 -0700
Subject: rustdoc: catch and don't blow up on impl Trait cycles

An odd feature of Rust is that `Foo` is invalid, but `Bar` is okay:

    type Foo<'a, 'b> = Box<dyn PartialEq<Foo<'a, 'b>>>;
    type Bar<'a, 'b> = impl PartialEq<Bar<'a, 'b>>;

To get it right, track every time rustdoc descends into a type alias,
so if it shows up twice, it can be write the path instead of
infinitely expanding it.
---
 tests/rustdoc/issue-110629-private-type-cycle.rs | 19 +++++++++++++++++++
 1 file changed, 19 insertions(+)
 create mode 100644 tests/rustdoc/issue-110629-private-type-cycle.rs

(limited to 'tests/rustdoc')

diff --git a/tests/rustdoc/issue-110629-private-type-cycle.rs b/tests/rustdoc/issue-110629-private-type-cycle.rs
new file mode 100644
index 00000000000..a4efbb098f7
--- /dev/null
+++ b/tests/rustdoc/issue-110629-private-type-cycle.rs
@@ -0,0 +1,19 @@
+// compile-flags: --document-private-items
+
+#![feature(type_alias_impl_trait)]
+
+type Bar<'a, 'b> = impl PartialEq<Bar<'a, 'b>> + std::fmt::Debug;
+
+// @has issue_110629_private_type_cycle/type.Bar.html
+// @has - '//pre[@class="rust item-decl"]' \
+//     "pub(crate) type Bar<'a, 'b> = impl PartialEq<Bar<'a, 'b>> + Debug;"
+
+fn bar<'a, 'b>(i: &'a i32) -> Bar<'a, 'b> {
+    i
+}
+
+fn main() {
+    let meh = 42;
+    let muh = 42;
+    assert_eq!(bar(&meh), bar(&muh));
+}
-- 
cgit 1.4.1-3-g733a5