Rollup merge of rust-lang#54087 - ollie27:rustdoc_blanket_impl, r=QuietMisdreavus

rustdoc: Remove generated blanket impls from trait pages

rust-lang#53801 only deduped the generated blanket impls but they shouldn't be displayed at all because the original blanket impl is already in the "Implementors" section. This also removes the impls from the sidebar.

Fixes rust-lang#53689

r? @QuietMisdreavus

Author: kennytm

Diff for: src/librustdoc/html/render.rs

@@ -1257,9 +1257,11 @@ impl DocFolder for Cache {
         // Collect all the implementors of traits.
         if let clean::ImplItem(ref i) = item.inner {
             if let Some(did) = i.trait_.def_id() {
-                self.implementors.entry(did).or_default().push(Impl {
-                    impl_item: item.clone(),
-                });
+                if i.blanket_impl.is_none() {
+                    self.implementors.entry(did).or_default().push(Impl {
+                        impl_item: item.clone(),
+                    });
+                }
             }
         }
 
@@ -2931,7 +2933,6 @@ fn item_trait(
 
 
         let (synthetic, concrete): (Vec<&&Impl>, Vec<&&Impl>) = local.iter()
-            .filter(|i| i.inner_impl().blanket_impl.is_none())
             .partition(|i| i.inner_impl().synthetic);
 
         if !foreign.is_empty() {
@@ -2941,17 +2942,14 @@ fn item_trait(
                 </h2>
             ")?;
 
-            let mut foreign_cache = FxHashSet();
             for implementor in foreign {
-                if foreign_cache.insert(implementor.inner_impl().to_string()) {
-                    let assoc_link = AssocItemLink::GotoSource(
-                        implementor.impl_item.def_id,
-                        &implementor.inner_impl().provided_trait_methods
-                    );
-                    render_impl(w, cx, &implementor, assoc_link,
-                                RenderMode::Normal, implementor.impl_item.stable_since(), false,
-                                None)?;
-                }
+                let assoc_link = AssocItemLink::GotoSource(
+                    implementor.impl_item.def_id,
+                    &implementor.inner_impl().provided_trait_methods
+                );
+                render_impl(w, cx, &implementor, assoc_link,
+                            RenderMode::Normal, implementor.impl_item.stable_since(), false,
+                            None)?;
             }
         }
 

Diff for: src/test/rustdoc/auxiliary/issue-53689.rs

@@ -0,0 +1,11 @@
+// Copyright 2018 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.
+
+pub struct MyStruct;

Diff for: src/test/rustdoc/issue-53689.rs

@@ -0,0 +1,26 @@
+// Copyright 2018 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.
+
+// aux-build:issue-53689.rs
+
+#![crate_name = "foo"]
+
+extern crate issue_53689;
+
+// @has foo/trait.MyTrait.html
+// @!has - 'MyStruct'
+// @count - '//*[code="impl<T> MyTrait for T"]' 1
+pub trait MyTrait {}
+
+impl<T> MyTrait for T {}
+
+mod a {
+    pub use issue_53689::MyStruct;
+}