From 5a81c7d4b0bdbb82ef6018fe4200cf74479e12c6 Mon Sep 17 00:00:00 2001
From: topecongiro <seuchida@gmail.com>
Date: Thu, 27 Jul 2017 11:09:38 +0900
Subject: [PATCH] Use correct BytePos for where when rewriting trait

---
 src/items.rs                     | 12 +++++++++---
 tests/target/issue-1824.rs       |  5 +++++
 tests/target/trait.rs            |  6 +++---
 tests/target/where-clause-rfc.rs |  2 +-
 4 files changed, 18 insertions(+), 7 deletions(-)
 create mode 100644 tests/target/issue-1824.rs

diff --git a/src/items.rs b/src/items.rs
index cd2cdf28fe64..463614712062 100644
--- a/src/items.rs
+++ b/src/items.rs
@@ -962,8 +962,14 @@ pub fn format_trait(context: &RewriteContext, item: &ast::Item, offset: Indent)
                 .checked_sub(last_line_width(&result))
         );
         let pos_before_where = if type_param_bounds.is_empty() {
-            // We do not use this, so it does not matter
-            generics.span.hi
+            if generics.where_clause.predicates.is_empty() {
+                // We do not use this, so it does not matter
+                item.span.lo
+            } else {
+                let snippet = context.snippet(item.span);
+                let where_pos = snippet.find_uncommented("where");
+                item.span.lo + where_pos.map_or(BytePos(0), |p| BytePos(p as u32))
+            }
         } else {
             type_param_bounds[type_param_bounds.len() - 1].span().hi
         };
@@ -974,7 +980,7 @@ pub fn format_trait(context: &RewriteContext, item: &ast::Item, offset: Indent)
             Shape::legacy(where_budget, offset.block_only()),
             where_density,
             "{",
-            !has_body,
+            false,
             trait_bound_str.is_empty() && last_line_width(&generics_str) == 1,
             None,
             item.span,
diff --git a/tests/target/issue-1824.rs b/tests/target/issue-1824.rs
new file mode 100644
index 000000000000..1c4c2db46dcb
--- /dev/null
+++ b/tests/target/issue-1824.rs
@@ -0,0 +1,5 @@
+pub trait Ingredient
+where
+    Self: Send,
+{
+}
diff --git a/tests/target/trait.rs b/tests/target/trait.rs
index e4758e98b5e9..cb1e0beb5551 100644
--- a/tests/target/trait.rs
+++ b/tests/target/trait.rs
@@ -54,13 +54,13 @@ trait ConstCheck<T>: Foo
 
 trait Tttttttttttttttttttttttttttttttttttttttttttttttttttttttttt<T>
 where
-    T: Foo
+    T: Foo,
 {
 }
 
 trait Ttttttttttttttttttttttttttttttttttttttttttttttttttttttttttt<T>
 where
-    T: Foo
+    T: Foo,
 {
 }
 
@@ -75,6 +75,6 @@ trait FooBar<T>
 trait WhereList<T, J>
 where
     T: Foo,
-    J: Bar
+    J: Bar,
 {
 }
diff --git a/tests/target/where-clause-rfc.rs b/tests/target/where-clause-rfc.rs
index bdf1f9d25742..ebfdc073eaa7 100644
--- a/tests/target/where-clause-rfc.rs
+++ b/tests/target/where-clause-rfc.rs
@@ -110,6 +110,6 @@ pub trait SomeTrait<T>
         + Display
         + Write
         + Read
-        + FromStr
+        + FromStr,
 {
 }