From 645a1b5d739e7101fc63cea7950d26addd8e7be2 Mon Sep 17 00:00:00 2001
From: Aleksey Kladov <aleksey.kladov@gmail.com>
Date: Mon, 22 Jan 2018 02:21:53 +0300
Subject: [PATCH] Remove high-order bits from tuple struct

---
 src/parser/event_parser/grammar/items.rs      | 15 +++++++-----
 .../parser/ok/0017_attr_trailing_comma.rs     |  2 ++
 .../parser/ok/0017_attr_trailing_comma.txt    | 23 +++++++++++++++++++
 3 files changed, 34 insertions(+), 6 deletions(-)
 create mode 100644 tests/data/parser/ok/0017_attr_trailing_comma.rs
 create mode 100644 tests/data/parser/ok/0017_attr_trailing_comma.txt

diff --git a/src/parser/event_parser/grammar/items.rs b/src/parser/event_parser/grammar/items.rs
index 12b6d06c73..d341dce383 100644
--- a/src/parser/event_parser/grammar/items.rs
+++ b/src/parser/event_parser/grammar/items.rs
@@ -127,18 +127,21 @@ fn pos_fields(p: &mut Parser) {
     if !p.expect(L_PAREN) {
         return;
     }
-    comma_list(p, R_PAREN, |p| {
-        pos_field(p);
-        true
-    });
-    p.expect(R_PAREN);
+    loop {
+        if p.at(R_PAREN) || p.at(EOF) {
+            break;
+        }
 
-    fn pos_field(p: &mut Parser) {
         let pos_field = p.start();
         visibility(p);
         types::type_ref(p);
         pos_field.complete(p, POS_FIELD);
+
+        if !p.at(R_PAREN) {
+            p.expect(COMMA);
+        }
     }
+    p.expect(R_PAREN);
 }
 
 fn generic_parameters(_: &mut Parser) {}
diff --git a/tests/data/parser/ok/0017_attr_trailing_comma.rs b/tests/data/parser/ok/0017_attr_trailing_comma.rs
new file mode 100644
index 0000000000..fe0a7bb97e
--- /dev/null
+++ b/tests/data/parser/ok/0017_attr_trailing_comma.rs
@@ -0,0 +1,2 @@
+#[foo(a,)]
+fn foo() {}
diff --git a/tests/data/parser/ok/0017_attr_trailing_comma.txt b/tests/data/parser/ok/0017_attr_trailing_comma.txt
new file mode 100644
index 0000000000..1b99d7ffdf
--- /dev/null
+++ b/tests/data/parser/ok/0017_attr_trailing_comma.txt
@@ -0,0 +1,23 @@
+FILE@[0; 23)
+  FN_ITEM@[0; 23)
+    ATTR@[0; 11)
+      POUND@[0; 1)
+      L_BRACK@[1; 2)
+      META_ITEM@[2; 9)
+        IDENT@[2; 5)
+        L_PAREN@[5; 6)
+        META_ITEM@[6; 7)
+          IDENT@[6; 7)
+        COMMA@[7; 8)
+        R_PAREN@[8; 9)
+      R_BRACK@[9; 10)
+      WHITESPACE@[10; 11)
+    FN_KW@[11; 13)
+    WHITESPACE@[13; 14)
+    IDENT@[14; 17)
+    L_PAREN@[17; 18)
+    R_PAREN@[18; 19)
+    WHITESPACE@[19; 20)
+    L_CURLY@[20; 21)
+    R_CURLY@[21; 22)
+    WHITESPACE@[22; 23)