Auto merge of #50474 - sinkuu:fix_assert_ice, r=alexcrichton

Fix ICE in assertion macro

Fixes #50471. Needs beta-backport (stable-to-beta/nightly regression).

* `panic` with single argument does not need escaping `{` and `}`
* Instead of unescaping `\u{...}` manually, just use `escape_debug` in pprust

1 files changed, 19 insertions, 0 deletions

diff --git a/src/test/compile-fail/issue-50471.rs b/src/test/compile-fail/issue-50471.rs
new file mode 100644
index 00000000000..ce2947144af
--- /dev/null
+++ b/src/test/compile-fail/issue-50471.rs
@@ -0,0 +1,19 @@
+// Copyright 2018 The Rust Project Developers. See the COPYRIGHT
+// file at the top-level directory of this distribution and at
+// http://rust-lang.org/COPYRIGHT.
+//
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+// compile-pass
+
+fn main() {
+    assert!({false});
+
+    assert!(r"\u{41}" == "A");
+
+    assert!(r"\u{".is_empty());
+}