1 files changed, 56 insertions, 0 deletions
diff --git a/tests/ui/implied-bounds/normalization-placeholder-leak.rs b/tests/ui/implied-bounds/normalization-placeholder-leak.rs
new file mode 100644
index 000000000..5350dcbb2
--- /dev/null
+++ b/tests/ui/implied-bounds/normalization-placeholder-leak.rs
@@ -0,0 +1,56 @@
+// Because of #109628, when we compute the implied bounds from `Foo<X>`,
+// we incorrectly get `X: placeholder('x)`.
+// Make sure we ignore these bogus bounds and not use them for anything useful.
+//
+// revisions: fail pass
+// [fail] check-fail
+// [pass] check-pass
+
+trait Trait {
+    type Ty<'a> where Self: 'a;
+}
+
+impl<T> Trait for T {
+    type Ty<'a> = () where Self: 'a;
+}
+
+struct Foo<T: Trait>(T)
+where
+    for<'x> T::Ty<'x>: Sized;
+
+trait AnotherTrait {
+    type Ty2<'a>: 'a;
+}
+
+#[cfg(fail)]
+mod fail {
+    use super::*;
+
+    // implied_bound: `'lt: placeholder('x)`.
+    // don't use the bound to prove `'lt: 'static`.
+    fn test_lifetime<'lt, T: Trait>(_: Foo<&'lt u8>) {}
+    //[fail]~^ ERROR `&'lt u8` does not fulfill the required lifetime
+
+    // implied bound: `T::Ty2<'lt>: placeholder('x)`.
+    // don't use the bound to prove `T::Ty2<'lt>: 'static`.
+    fn test_alias<'lt, T: AnotherTrait>(_: Foo<T::Ty2::<'lt>>) {}
+    //[fail]~^ ERROR `<T as AnotherTrait>::Ty2<'lt>` does not fulfill the required lifetime
+}
+
+
+mod pass {
+    use super::*;
+
+    // implied_bound: 'static: placeholder('x).
+    // don't ice.
+    fn test_lifetime<T: Trait>(_: Foo<&'static u8>) {}
+
+    // implied bound: T::Ty2<'static>: placeholder('x).
+    // don't add the bound to the environment,
+    // otherwise we would fail to infer a value for `'_`.
+    fn test_alias<T: AnotherTrait>(_: Foo<T::Ty2::<'static>>) {
+        None::<&'static T::Ty2<'_>>;
+    }
+}
+
+fn main() {}