Fix and test edge cases of `_` as ident

1 files changed, 2 insertions, 3 deletions

diff --git a/crates/mbe/src/expander/matcher.rs b/crates/mbe/src/expander/matcher.rs
index 3c53960ce..1682b21b0 100644
--- a/crates/mbe/src/expander/matcher.rs
+++ b/crates/mbe/src/expander/matcher.rs
@@ -710,7 +710,6 @@ fn match_meta_var(kind: &str, input: &mut TtIter) -> ExpandResult<Option<Fragmen
             let tt_result = match kind {
                 "ident" => input
                     .expect_ident()
-                    .and_then(|ident| if ident.text == "_" { Err(()) } else { Ok(ident) })
                     .map(|ident| Some(tt::Leaf::from(ident.clone()).into()))
                     .map_err(|()| err!("expected ident")),
                 "tt" => input.expect_tt().map(Some).map_err(|()| err!()),
@@ -763,7 +762,7 @@ impl<'a> TtIter<'a> {
     fn expect_separator(&mut self, separator: &Separator, idx: usize) -> bool {
         let mut fork = self.clone();
         let ok = match separator {
-            Separator::Ident(lhs) if idx == 0 => match fork.expect_ident() {
+            Separator::Ident(lhs) if idx == 0 => match fork.expect_ident_or_underscore() {
                 Ok(rhs) => rhs.text == lhs.text,
                 _ => false,
             },
@@ -853,7 +852,7 @@ impl<'a> TtIter<'a> {
         if punct.char != '\'' {
             return Err(());
         }
-        let ident = self.expect_ident()?;
+        let ident = self.expect_ident_or_underscore()?;
 
         Ok(tt::Subtree {
             delimiter: None,