Propogate error types in mir type projections

1 files changed, 13 insertions, 0 deletions

diff --git a/src/tools/rust-analyzer/crates/ide-diagnostics/src/handlers/unused_variables.rs b/src/tools/rust-analyzer/crates/ide-diagnostics/src/handlers/unused_variables.rs
index 67ece566941..d5caf4de336 100644
--- a/src/tools/rust-analyzer/crates/ide-diagnostics/src/handlers/unused_variables.rs
+++ b/src/tools/rust-analyzer/crates/ide-diagnostics/src/handlers/unused_variables.rs
@@ -263,4 +263,17 @@ fn main() {
 "#,
         );
     }
+
+    // regression test as we used to panic in this scenario
+    #[test]
+    fn unknown_struct_pattern_param_type() {
+        check_diagnostics(
+            r#"
+struct S { field : u32 }
+fn f(S { field }: error) {
+      // ^^^^^ 💡 warn: unused variable
+}
+"#,
+        );
+    }
 }