Rollup merge of #65235 - nikomatsakis:issue-65159-async-fn-return-ice, r=cramertj

don't assume we can *always* find a return type hint in async fn

In particular, we sometimes cannot if there is an earlier error.

Fixes #65159

r? @cramertj, who reviewed the original PR

2 files changed, 19 insertions, 0 deletions

diff --git a/src/test/ui/async-await/issues/issue-65159.rs b/src/test/ui/async-await/issues/issue-65159.rs
new file mode 100644
index 00000000000..b5fee061f27
--- /dev/null
+++ b/src/test/ui/async-await/issues/issue-65159.rs
@@ -0,0 +1,10 @@
+// Regression test for #65159. We used to ICE.
+//
+// edition:2018
+
+async fn copy() -> Result<()> //~ ERROR wrong number of type arguments
+{
+    Ok(())
+}
+
+fn main() { }
diff --git a/src/test/ui/async-await/issues/issue-65159.stderr b/src/test/ui/async-await/issues/issue-65159.stderr
new file mode 100644
index 00000000000..56d2c38b302
--- /dev/null
+++ b/src/test/ui/async-await/issues/issue-65159.stderr
@@ -0,0 +1,9 @@
+error[E0107]: wrong number of type arguments: expected 2, found 1
+  --> $DIR/issue-65159.rs:5:20
+   |
+LL | async fn copy() -> Result<()>
+   |                    ^^^^^^^^^^ expected 2 type arguments
+
+error: aborting due to previous error
+
+For more information about this error, try `rustc --explain E0107`.