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diff --git a/tests/ui/traits/next-solver/generalize/generalize-proj-new-universe-index-2.rs b/tests/ui/traits/next-solver/generalize/generalize-proj-new-universe-index-2.rs
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+++ b/tests/ui/traits/next-solver/generalize/generalize-proj-new-universe-index-2.rs
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+// compile-flags: -Znext-solver
+// known-bug: trait-system-refactor-initiative#60
+
+// Generalizing a projection containing an inference variable
+// which cannot be named by the `root_vid` can result in ambiguity.
+//
+// Because we do not decrement the universe index when exiting a forall,
+// this can cause unexpected failures.
+//
+// See generalize-proj-new-universe-index-1.rs for more details.
+
+// For this reproduction we need:
+// - an inference variable with a lower universe
+// - enter a binder to increment the current universe
+// - create a new inference variable which is constrained by proving a goal
+// - equate a projection containing the new variable with the first variable
+// - generalization creates yet another inference variable which is then
+// part of an alias-relate, resulting this to fail with ambiguity.
+//
+// Because we need to enter the binder in-between the creation of the first
+// and second inference variable, this is easiest via
+// `assemble_candidates_after_normalizing_self_ty` because eagerly call
+// `try_evaluate_added_goals` there before creating the inference variables
+// for the impl parameters.
+trait Id {
+ type Assoc: ?Sized;
+}
+impl<T: ?Sized> Id for T {
+ type Assoc = T;
+}
+
+// By adding an higher ranked bound to the impl we currently
+// propagate this bound to the caller, forcing us to create a new
+// universe.
+trait IdHigherRankedBound {
+ type Assoc: ?Sized;
+}
+
+impl<T: ?Sized> IdHigherRankedBound for T
+where
+ for<'a> T: 'a,
+{
+ type Assoc = T;
+}
+
+trait WithAssoc<T: ?Sized> {
+ type Assoc: ?Sized;
+}
+
+
+struct Leaf;
+struct Wrapper<U: ?Sized>(U);
+struct Rigid;
+
+impl<U: ?Sized> WithAssoc<U> for Leaf {
+ type Assoc = U;
+}
+
+
+impl<Ur: ?Sized> WithAssoc<Wrapper<Ur>> for Rigid
+where
+ Leaf: WithAssoc<Ur>,
+{
+ type Assoc = <<Leaf as WithAssoc<Ur>>::Assoc as Id>::Assoc;
+}
+
+fn bound<T: ?Sized, U: ?Sized, V: ?Sized>()
+where
+ T: WithAssoc<U, Assoc = V>,
+{
+}
+
+fn main() {
+ bound::<<Rigid as IdHigherRankedBound>::Assoc, <Wrapper<Leaf> as Id>::Assoc, _>()
+}