From f5715f7867ab7e13fd3304d85861b1dcb1375a89 Mon Sep 17 00:00:00 2001
From: P1start <rewi-github@whanau.org>
Date: Sun, 30 Nov 2014 17:39:50 +1300
Subject: [PATCH] Allow trailing commas in array patterns and attributes

---
 src/libsyntax/parse/attr.rs                         |  2 +-
 src/libsyntax/parse/common.rs                       |  7 +------
 src/libsyntax/parse/parser.rs                       |  5 +++++
 .../compile-fail/trailing-comma-array-repeat.rs     | 13 +++++++++++++
 src/test/run-pass/trailing-comma.rs                 |  6 ++++++
 5 files changed, 26 insertions(+), 7 deletions(-)
 create mode 100644 src/test/compile-fail/trailing-comma-array-repeat.rs

diff --git a/src/libsyntax/parse/attr.rs b/src/libsyntax/parse/attr.rs
index 0c919daa8ed..40703049cc3 100644
--- a/src/libsyntax/parse/attr.rs
+++ b/src/libsyntax/parse/attr.rs
@@ -212,7 +212,7 @@ impl<'a> ParserAttr for Parser<'a> {
     fn parse_meta_seq(&mut self) -> Vec<P<ast::MetaItem>> {
         self.parse_seq(&token::OpenDelim(token::Paren),
                        &token::CloseDelim(token::Paren),
-                       seq_sep_trailing_disallowed(token::Comma),
+                       seq_sep_trailing_allowed(token::Comma),
                        |p| p.parse_meta_item()).node
     }
 
diff --git a/src/libsyntax/parse/common.rs b/src/libsyntax/parse/common.rs
index 3842170d677..a96bf1ce10b 100644
--- a/src/libsyntax/parse/common.rs
+++ b/src/libsyntax/parse/common.rs
@@ -19,18 +19,13 @@ pub struct SeqSep {
     pub trailing_sep_allowed: bool
 }
 
-pub fn seq_sep_trailing_disallowed(t: token::Token) -> SeqSep {
-    SeqSep {
-        sep: Some(t),
-        trailing_sep_allowed: false,
-    }
-}
 pub fn seq_sep_trailing_allowed(t: token::Token) -> SeqSep {
     SeqSep {
         sep: Some(t),
         trailing_sep_allowed: true,
     }
 }
+
 pub fn seq_sep_none() -> SeqSep {
     SeqSep {
         sep: None,
diff --git a/src/libsyntax/parse/parser.rs b/src/libsyntax/parse/parser.rs
index 447f2a376e1..9623a1b75b5 100644
--- a/src/libsyntax/parse/parser.rs
+++ b/src/libsyntax/parse/parser.rs
@@ -3129,6 +3129,11 @@ impl<'a> Parser<'a> {
                 first = false;
             } else {
                 self.expect(&token::Comma);
+
+                if self.token == token::CloseDelim(token::Bracket)
+                        && (before_slice || after.len() != 0) {
+                    break
+                }
             }
 
             if before_slice {
diff --git a/src/test/compile-fail/trailing-comma-array-repeat.rs b/src/test/compile-fail/trailing-comma-array-repeat.rs
new file mode 100644
index 00000000000..dadd6571583
--- /dev/null
+++ b/src/test/compile-fail/trailing-comma-array-repeat.rs
@@ -0,0 +1,13 @@
+// Copyright 2014 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.
+
+fn main() {
+    let [_, ..,] = [(), ()]; //~ ERROR unexpected token: `]`
+}
diff --git a/src/test/run-pass/trailing-comma.rs b/src/test/run-pass/trailing-comma.rs
index 5e93f8eedb7..00e05064080 100644
--- a/src/test/run-pass/trailing-comma.rs
+++ b/src/test/run-pass/trailing-comma.rs
@@ -8,6 +8,8 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
+#![feature(advanced_slice_patterns,)]
+
 fn f<T,>(_: T,) {}
 
 struct Foo<T,>;
@@ -24,9 +26,13 @@ enum Baz {
     Qux(int,),
 }
 
+#[allow(unused,)]
 pub fn main() {
     f::<int,>(0i,);
     let (_, _,) = (1i, 1i,);
+    let [_, _,] = [1i, 1,];
+    let [_, _, .., _,] = [1i, 1, 1, 1,];
+    let [_, _, _.., _,] = [1i, 1, 1, 1,];
 
     let x: Foo<int,> = Foo::<int,>;