From 66ac5a2d6380778e6ca29924e1c7f8287cb851a9 Mon Sep 17 00:00:00 2001
From: LeSeulArtichaut <leseulartichaut@gmail.com>
Date: Mon, 19 Oct 2020 23:14:28 +0200
Subject: [PATCH 1/2] Do not ICE on pattern that uses a binding multiple times
 in generator

---
 compiler/rustc_typeck/src/check/generator_interior.rs | 5 +----
 1 file changed, 1 insertion(+), 4 deletions(-)

diff --git a/compiler/rustc_typeck/src/check/generator_interior.rs b/compiler/rustc_typeck/src/check/generator_interior.rs
index 3fc5f02a4a47d..4473aa2081f23 100644
--- a/compiler/rustc_typeck/src/check/generator_interior.rs
+++ b/compiler/rustc_typeck/src/check/generator_interior.rs
@@ -250,10 +250,7 @@ impl<'a, 'tcx> Visitor<'tcx> for InteriorVisitor<'a, 'tcx> {
             let mut scope_var_ids =
                 self.guard_bindings.pop().expect("should have pushed at least one earlier");
             for var_id in scope_var_ids.drain(..) {
-                assert!(
-                    self.guard_bindings_set.remove(&var_id),
-                    "variable should be placed in scope earlier"
-                );
+                self.guard_bindings_set.remove(&var_id);
             }
         }
         self.visit_expr(body);

From 334c6c54337b2cfd367f1dd9f696ecacd9369d8d Mon Sep 17 00:00:00 2001
From: LeSeulArtichaut <leseulartichaut@gmail.com>
Date: Mon, 19 Oct 2020 23:32:07 +0200
Subject: [PATCH 2/2] Add regression test

---
 src/test/ui/issues/issue-78115.rs | 19 +++++++++++++++++++
 1 file changed, 19 insertions(+)
 create mode 100644 src/test/ui/issues/issue-78115.rs

diff --git a/src/test/ui/issues/issue-78115.rs b/src/test/ui/issues/issue-78115.rs
new file mode 100644
index 0000000000000..ac18470c62113
--- /dev/null
+++ b/src/test/ui/issues/issue-78115.rs
@@ -0,0 +1,19 @@
+// Regression test for issue #78115: "ICE: variable should be placed in scope earlier"
+
+// check-pass
+// edition:2018
+
+#[allow(dead_code)]
+struct Foo {
+    a: ()
+}
+
+async fn _bar() {
+    let foo = Foo { a: () };
+    match foo {
+        Foo { a: _a } | Foo { a: _a } if true => {}
+        _ => {}
+    }
+}
+
+fn main() {}