Handle case of incomplete local ty more gracefully

When encountering a local binding with a type that isn't completed, the
parser will reach a `=` token. When this happen, consider the type
"complete" as far as the parser is concerned to avoid further errors
being emitted by parse recovery logic.

1 files changed, 10 insertions, 4 deletions

diff --git a/src/librustc_parse/parser/stmt.rs b/src/librustc_parse/parser/stmt.rs
index 53f32b7c800..d04920de47f 100644
--- a/src/librustc_parse/parser/stmt.rs
+++ b/src/librustc_parse/parser/stmt.rs
@@ -162,13 +162,19 @@ impl<'a> Parser<'a> {
             match self.parse_ty() {
                 Ok(ty) => (None, Some(ty)),
                 Err(mut err) => {
-                    // Rewind to before attempting to parse the type and continue parsing.
-                    let parser_snapshot_after_type =
-                        mem::replace(self, parser_snapshot_before_type);
                     if let Ok(snip) = self.span_to_snippet(pat.span) {
                         err.span_label(pat.span, format!("while parsing the type for `{}`", snip));
                     }
-                    (Some((parser_snapshot_after_type, colon_sp, err)), None)
+                    let err = if self.check(&token::Eq) {
+                        err.emit();
+                        None
+                    } else {
+                        // Rewind to before attempting to parse the type and continue parsing.
+                        let parser_snapshot_after_type =
+                            mem::replace(self, parser_snapshot_before_type);
+                        Some((parser_snapshot_after_type, colon_sp, err))
+                    };
+                    (err, None)
                 }
             }
         } else {