From 489403fdfc786e27c405fd047b6a45bed8530896 Mon Sep 17 00:00:00 2001
From: rchaser53 <tayoshizawa29@gmail.com>
Date: Thu, 6 Jun 2019 00:32:59 +0900
Subject: [PATCH 1/2] fix the bug add unwanted code to impl (#3601)

---
 src/items.rs               |  9 ++++-----
 tests/target/issue-3601.rs | 11 +++++++++++
 2 files changed, 15 insertions(+), 5 deletions(-)
 create mode 100644 tests/target/issue-3601.rs

diff --git a/src/items.rs b/src/items.rs
index 4ae3f383e74..99e33762771 100644
--- a/src/items.rs
+++ b/src/items.rs
@@ -700,8 +700,8 @@ pub(crate) fn format_impl(
             option.allow_single_line();
         }
 
-        let misssing_span = mk_sp(self_ty.span.hi(), item.span.hi());
-        let where_span_end = context.snippet_provider.opt_span_before(misssing_span, "{");
+        let missing_span = mk_sp(self_ty.span.hi(), item.span.hi());
+        let where_span_end = context.snippet_provider.opt_span_before(missing_span, "{");
         let where_clause_str = rewrite_where_clause(
             context,
             &generics.where_clause,
@@ -765,15 +765,14 @@ pub(crate) fn format_impl(
         }
 
         result.push('{');
-
-        let snippet = context.snippet(item.span);
+        let snippet = context.snippet(mk_sp(item.span.hi(), self_ty.span.hi()));
         let open_pos = snippet.find_uncommented("{")? + 1;
 
         if !items.is_empty() || contains_comment(&snippet[open_pos..]) {
             let mut visitor = FmtVisitor::from_context(context);
             let item_indent = offset.block_only().block_indent(context.config);
             visitor.block_indent = item_indent;
-            visitor.last_pos = item.span.lo() + BytePos(open_pos as u32);
+            visitor.last_pos = self_ty.span.hi() + BytePos(open_pos as u32);
 
             visitor.visit_attrs(&item.attrs, ast::AttrStyle::Inner);
             visitor.visit_impl_items(items);
diff --git a/tests/target/issue-3601.rs b/tests/target/issue-3601.rs
new file mode 100644
index 00000000000..c86ca24e707
--- /dev/null
+++ b/tests/target/issue-3601.rs
@@ -0,0 +1,11 @@
+#![feature(const_generics)]
+
+trait A {
+    fn foo(&self);
+}
+
+pub struct B<const N: usize>([usize; N]);
+
+impl<const N: usize> A for B<{ N }> {
+    fn foo(&self) {}
+}

From 19219de58277ff515c8a3534653e6610b011598c Mon Sep 17 00:00:00 2001
From: rchaser53 <tayoshizawa29@gmail.com>
Date: Thu, 6 Jun 2019 10:01:16 +0900
Subject: [PATCH 2/2] add comment to snippet

---
 src/items.rs | 1 +
 1 file changed, 1 insertion(+)

diff --git a/src/items.rs b/src/items.rs
index 99e33762771..14d386047f0 100644
--- a/src/items.rs
+++ b/src/items.rs
@@ -765,6 +765,7 @@ pub(crate) fn format_impl(
         }
 
         result.push('{');
+        // this is an impl body snippet(impl SampleImple { /* here */ })
         let snippet = context.snippet(mk_sp(item.span.hi(), self_ty.span.hi()));
         let open_pos = snippet.find_uncommented("{")? + 1;