Fix rendering on sidebar and update tests

src/librustdoc/html/render.rs

@@ -4126,14 +4126,14 @@ fn sidebar_assoc_items(it: &clean::Item) -> String {
                 .filter(|i| i.inner_impl().trait_.is_some())
                 .find(|i| i.inner_impl().trait_.def_id() == c.deref_trait_did)
             {
-                if let Some(target) = impl_
+                if let Some((target, real_target)) = impl_
                     .inner_impl()
                     .items
                     .iter()
                     .filter_map(|item| match item.inner {
                         clean::TypedefItem(ref t, true) => Some(match *t {
-                            clean::Typedef { item_type: Some(ref type_), .. } => type_,
-                            _ => &t.type_,
+                            clean::Typedef { item_type: Some(ref type_), .. } => (type_, &t.type_),
+                            _ => (&t.type_, &t.type_),
                         }),
                         _ => None,
                     })
@@ -4153,7 +4153,7 @@ fn sidebar_assoc_items(it: &clean::Item) -> String {
                                 "{:#}",
                                 impl_.inner_impl().trait_.as_ref().unwrap().print()
                             )),
-                            Escape(&format!("{:#}", target.print()))
+                            Escape(&format!("{:#}", real_target.print()))
                         ));
                         out.push_str("</a>");
                         let mut ret = impls

src/test/rustdoc/deref-typedef.rs

@@ -1,19 +1,33 @@
 #![crate_name = "foo"]
 
 // @has 'foo/struct.Bar.html'
-// @has '-' '//*[@id="deref-methods"]' 'Methods from Deref<Target = FooB>'
-// @has '-' '//*[@class="impl-items"]//*[@id="method.happy"]' 'pub fn happy(&self)'
-// @has '-' '//*[@class="sidebar-title"]' 'Methods from Deref<Target=FooB>'
-// @has '-' '//*[@class="sidebar-links"]/a[@href="#method.happy"]' 'happy'
+// @has '-' '//*[@id="deref-methods"]' 'Methods from Deref<Target = FooC>'
+// @has '-' '//*[@class="impl-items"]//*[@id="method.foo_a"]' 'pub fn foo_a(&self)'
+// @has '-' '//*[@class="impl-items"]//*[@id="method.foo_b"]' 'pub fn foo_b(&self)'
+// @has '-' '//*[@class="impl-items"]//*[@id="method.foo_c"]' 'pub fn foo_c(&self)'
+// @has '-' '//*[@class="sidebar-title"]' 'Methods from Deref<Target=FooC>'
+// @has '-' '//*[@class="sidebar-links"]/a[@href="#method.foo_a"]' 'foo_a'
+// @has '-' '//*[@class="sidebar-links"]/a[@href="#method.foo_b"]' 'foo_b'
+// @has '-' '//*[@class="sidebar-links"]/a[@href="#method.foo_c"]' 'foo_c'
+
 pub struct FooA;
 pub type FooB = FooA;
+pub type FooC = FooB;
 
 impl FooA {
-    pub fn happy(&self) {}
+    pub fn foo_a(&self) {}
+}
+
+impl FooB {
+    pub fn foo_b(&self) {}
+}
+
+impl FooC {
+    pub fn foo_c(&self) {}
 }
 
 pub struct Bar;
 impl std::ops::Deref for Bar {
-    type Target = FooB;
-    fn deref(&self) -> &FooB { unimplemented!() }
+    type Target = FooC;
+    fn deref(&self) -> &Self::Target { unimplemented!() }
 }