From df626ea137af1436cb2e5eda19c145363db801c9 Mon Sep 17 00:00:00 2001
From: Alex Crichton <alex@alexcrichton.com>
Date: Tue, 18 Jun 2013 23:16:44 -0700
Subject: Fix compiling empty fmt! strings

---
 src/libsyntax/ext/fmt.rs | 5 +++++
 1 file changed, 5 insertions(+)

(limited to 'src/libsyntax/ext')

diff --git a/src/libsyntax/ext/fmt.rs b/src/libsyntax/ext/fmt.rs
index 74496ac5359..4425d54987c 100644
--- a/src/libsyntax/ext/fmt.rs
+++ b/src/libsyntax/ext/fmt.rs
@@ -249,6 +249,11 @@ fn pieces_to_expr(cx: @ExtCtxt, sp: span,
         }
     }
 
+    /* Short circuit an easy case up front (won't work otherwise) */
+    if pieces.len() == 0 {
+        return cx.expr_str_uniq(args[0].span, @"");
+    }
+
     let fmt_sp = args[0].span;
     let mut n = 0u;
     let nargs = args.len();
-- 
cgit 1.4.1-3-g733a5