1 files changed, 26 insertions, 0 deletions
diff --git a/tests/ui/fn/coerce-suggestion-infer-region.rs b/tests/ui/fn/coerce-suggestion-infer-region.rs
new file mode 100644
index 00000000000..7edb828c973
--- /dev/null
+++ b/tests/ui/fn/coerce-suggestion-infer-region.rs
@@ -0,0 +1,26 @@
+//! Functions with a mismatch between the expected and found type where the difference is a
+//! reference may trigger analysis for additional help. In this test the expected type will be
+//! &'a Container<&'a u8> and the found type will be Container<&'?0 u8>.
+//!
+//! This test exercises a scenario where the found type being analyzed contains an inference region
+//! variable ('?0). This cannot be used in comparisons because the variable no longer exists by the
+//! time the later analysis is performed.
+//!
+//! This is a regression test of #140823
+
+trait MyFn<P> {}
+
+struct Container<T> {
+    data: T,
+}
+
+struct Desugared {
+    callback: Box<dyn for<'a> MyFn<&'a Container<&'a u8>>>,
+}
+
+fn test(callback: Box<dyn for<'a> MyFn<Container<&'a u8>>>) -> Desugared {
+    Desugared { callback }
+    //~^ ERROR mismatched types
+}
+
+fn main() {}