Delegation: fix ICE on `bound_vars` divergence

2 files changed, 49 insertions, 0 deletions

diff --git a/tests/ui/delegation/ice-issue-122550.rs b/tests/ui/delegation/ice-issue-122550.rs
new file mode 100644
index 00000000000..92c0dda9605
--- /dev/null
+++ b/tests/ui/delegation/ice-issue-122550.rs
@@ -0,0 +1,18 @@
+#![feature(fn_delegation)]
+#![allow(incomplete_features)]
+
+trait Trait {
+    fn description(&self) -> &str {}
+    //~^ ERROR mismatched types
+}
+
+struct F;
+struct S(F);
+
+impl S {
+    reuse <S as Trait>::description { &self.0 }
+    //~^ ERROR mismatched types
+    //~| ERROR the trait bound `S: Trait` is not satisfied
+}
+
+fn main() {}
diff --git a/tests/ui/delegation/ice-issue-122550.stderr b/tests/ui/delegation/ice-issue-122550.stderr
new file mode 100644
index 00000000000..c92170644e7
--- /dev/null
+++ b/tests/ui/delegation/ice-issue-122550.stderr
@@ -0,0 +1,31 @@
+error[E0308]: mismatched types
+  --> $DIR/ice-issue-122550.rs:5:35
+   |
+LL |     fn description(&self) -> &str {}
+   |                                   ^^ expected `&str`, found `()`
+
+error[E0308]: mismatched types
+  --> $DIR/ice-issue-122550.rs:13:39
+   |
+LL |     reuse <S as Trait>::description { &self.0 }
+   |                                       ^^^^^^^ expected `&S`, found `&F`
+   |
+   = note: expected reference `&S`
+              found reference `&F`
+
+error[E0277]: the trait bound `S: Trait` is not satisfied
+  --> $DIR/ice-issue-122550.rs:13:12
+   |
+LL |     reuse <S as Trait>::description { &self.0 }
+   |            ^ the trait `Trait` is not implemented for `S`
+   |
+help: this trait has no implementations, consider adding one
+  --> $DIR/ice-issue-122550.rs:4:1
+   |
+LL | trait Trait {
+   | ^^^^^^^^^^^
+
+error: aborting due to 3 previous errors
+
+Some errors have detailed explanations: E0277, E0308.
+For more information about an error, try `rustc --explain E0277`.