From e685f041996d0a0e15afa17bda9ee1ae2dad3440 Mon Sep 17 00:00:00 2001
From: Josh Matthews <josh@joshmatthews.net>
Date: Sat, 2 Jul 2011 00:59:33 -0400
Subject: [PATCH] Fix assertion failure when syntax extension name is missing.

---
 src/comp/front/parser.rs            | 3 +++
 src/test/compile-fail/ext-noname.rs | 5 +++++
 2 files changed, 8 insertions(+)
 create mode 100644 src/test/compile-fail/ext-noname.rs

diff --git a/src/comp/front/parser.rs b/src/comp/front/parser.rs
index a3d20d23b6b32..78c7bf1c76f4e 100644
--- a/src/comp/front/parser.rs
+++ b/src/comp/front/parser.rs
@@ -966,6 +966,9 @@ fn parse_syntax_ext(&parser p) -> @ast::expr {
 
 fn parse_syntax_ext_naked(&parser p, uint lo) -> @ast::expr {
     auto pth = parse_path(p);
+    if (vec::len(pth.node.idents) == 0u) {
+        p.fatal("expected a syntax expander name");
+    }
     auto es = parse_seq(token::LPAREN, token::RPAREN,
                         some(token::COMMA), parse_expr, p);
     auto hi = es.span.hi;
diff --git a/src/test/compile-fail/ext-noname.rs b/src/test/compile-fail/ext-noname.rs
new file mode 100644
index 0000000000000..82395c710a8f3
--- /dev/null
+++ b/src/test/compile-fail/ext-noname.rs
@@ -0,0 +1,5 @@
+// error-pattern:expected a syntax expander name
+
+fn main() {
+  #();
+}
\ No newline at end of file