From eb7d47cba90ac716c84fe720418e58c6eb84ac4e Mon Sep 17 00:00:00 2001
From: Mark Mansi <markm@cs.wisc.edu>
Date: Wed, 8 May 2019 13:34:23 -0500
Subject: fix incorrect assert

---
 src/libsyntax/ext/tt/transcribe.rs | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

(limited to 'src/libsyntax')

diff --git a/src/libsyntax/ext/tt/transcribe.rs b/src/libsyntax/ext/tt/transcribe.rs
index 3a40e8403cc..0cefcf1ce03 100644
--- a/src/libsyntax/ext/tt/transcribe.rs
+++ b/src/libsyntax/ext/tt/transcribe.rs
@@ -71,7 +71,10 @@ pub fn transcribe(
     interp: &FxHashMap<Ident, Rc<NamedMatch>>,
     src: Vec<quoted::TokenTree>,
 ) -> TokenStream {
-    assert!(src.len() > 0);
+    // Nothing for us to transcribe...
+    if src.is_empty() {
+        return TokenStream::empty();
+    }
 
     // We descend into the RHS (`src`), expanding things as we go. This stack contains the things
     // we have yet to expand/are still expanding. We start the stack off with the whole RHS.
-- 
cgit 1.4.1-3-g733a5