unconstrained region vars: do not ICE ICE baby

2 files changed, 48 insertions, 0 deletions

diff --git a/tests/ui/implied-bounds/implied-bounds-unconstrained-1.rs b/tests/ui/implied-bounds/implied-bounds-unconstrained-1.rs
new file mode 100644
index 00000000000..025e5176ff7
--- /dev/null
+++ b/tests/ui/implied-bounds/implied-bounds-unconstrained-1.rs
@@ -0,0 +1,28 @@
+// check-pass
+
+// Regression test for #112832.
+pub trait QueryDb {
+    type Db;
+}
+
+pub struct QueryTable<Q, DB> {
+    db: DB,
+    storage: Q,
+}
+
+// We normalize `<Q as QueryDb>::Db` to `<Q as AsyncQueryFunction<'d>>::SendDb`
+// using the where-bound. 'd is an unconstrained region variable which previously
+// triggered an assert.
+impl<Q> QueryTable<Q, <Q as QueryDb>::Db> where Q: for<'d> AsyncQueryFunction<'d> {}
+
+pub trait AsyncQueryFunction<'d>: QueryDb<Db = <Self as AsyncQueryFunction<'d>>::SendDb> {
+    type SendDb: 'd;
+}
+
+pub trait QueryStorageOpsAsync<Q>
+where
+    Q: for<'d> AsyncQueryFunction<'d>,
+{
+}
+
+fn main() {}
diff --git a/tests/ui/implied-bounds/implied-bounds-unconstrained-2.rs b/tests/ui/implied-bounds/implied-bounds-unconstrained-2.rs
new file mode 100644
index 00000000000..976054facee
--- /dev/null
+++ b/tests/ui/implied-bounds/implied-bounds-unconstrained-2.rs
@@ -0,0 +1,20 @@
+// check-pass
+
+// Another minimized regression test for #112832.
+trait Trait {
+    type Assoc;
+}
+
+trait Sub<'a>: Trait<Assoc = <Self as Sub<'a>>::SubAssoc> {
+    type SubAssoc;
+}
+
+// By using the where-clause we normalize `<T as Trait>::Assoc` to
+// `<T as Sub<'a>>::SubAssoc` where `'a` is an unconstrained region
+// variable.
+fn foo<T>(x: <T as Trait>::Assoc)
+where
+    for<'a> T: Sub<'a>,
+{}
+
+fn main() {}