Rollup merge of #109422 - notriddle:notriddle/impl-disambiguate-search, r=GuillaumeGomez

rustdoc-search: add impl disambiguator to duplicate assoc items

Preview (to see the difference, click the link and pay attention to the specific function that comes up):

| Before | After |
|--|--|
| [`simd<i64>, simd<i64> -> simd<i64>`](https://doc.rust-lang.org/nightly/std/?search=simd%3Ci64%3E%2C%20simd%3Ci64%3E%20-%3E%20simd%3Ci64%3E) | [`simd<i64>, simd<i64> -> simd<i64>`](https://notriddle.com/rustdoc-demo-html-3/impl-disambiguate-search/std/index.html?search=simd%3Ci64%3E%2C%20simd%3Ci64%3E%20-%3E%20simd%3Ci64%3E) |
| [`cow, vec -> bool`](https://doc.rust-lang.org/nightly/std/?search=cow%2C%20vec%20-%3E%20bool) | [`cow, vec -> bool`](https://notriddle.com/rustdoc-demo-html-3/impl-disambiguate-search/std/index.html?search=cow%2C%20vec%20-%3E%20bool)

Helps with #90929

This changes the search results, specifically, when there's more than one impl with an associated item with the same name. For example, the search queries `simd<i8> -> simd<i8>` and `simd<i64> -> simd<i64>` don't link to the same function, but most of the functions have the same names.

This change should probably be FCP-ed, especially since it adds a new anchor link format for `main.js` to handle, so that URLs like `struct.Vec.html#impl-AsMut<[T]>-for-Vec<T,+A>/method.as_mut` redirect to `struct.Vec.html#method.as_mut-2`. It's a strange design, but there are a few reasons for it:

* I'd like to avoid making the HTML bigger. Obviously, fixing this bug is going to add at least a little more data to the search index, but adding more HTML penalises viewers for the benefit of searchers.

* Breaking `struct.Vec.html#method.len` would also be a disappointment.

On the other hand:

* The path-style anchors might be less prone to link rot than the numbered anchors. It's definitely less likely to have URLs that appear to "work", but silently point at the wrong thing.

* This commit arranges the path-style anchor to redirect to the numbered anchor. Nothing stops rustdoc from doing the opposite, making path-style anchors the default and redirecting the "legacy" numbered ones.

### The bug

On the "Before" links, this example search calls for `i64`:

![image](https://github.com/rust-lang/rust/assets/1593513/9431d89d-41dc-4f68-bbb1-3e2704a973d2)

But if I click any of the results, I get `f64` instead.

![image](https://github.com/rust-lang/rust/assets/1593513/6d89c692-1847-421a-84d9-22e359d9cf82)

The PR fixes this problem by adding enough information to the search result `href` to disambiguate methods with different types but the same name.

More detailed description of the problem at:
https://github.com/rust-lang/rust/pull/109422#issuecomment-1491089293

> When a struct/enum/union has multiple impls with different type parameters, it can have multiple methods that have the same name, but which are on different impls. Besides Simd, [Any](https://doc.rust-lang.org/nightly/std/any/trait.Any.html?search=any%3A%3Adowncast) also demonstrates this pattern. It has three methods named `downcast`, on three different impls.
>
> When that happens, it presents a challenge in linking to the method. Normally we link like `#method.foo`. When there are multiple `foo`, we number them like `#method.foo`, `#method.foo-1`, `#method.foo-2`, etc.
>
> It also presents a challenge for our search code. Currently we store all the variants in the index, but don’t have any way to generate unambiguous URLs in the results page, or to distinguish them in the SERP.
>
> To fix this, we need three things:
>
> 1. A fragment format that fully specifies the impl type parameters when needed to disambiguate (`#impl-SimdOrd-for-Simd<i64,+LANES>/method.simd_max`)
> 2. A search index that stores methods with enough information to disambiguate the impl they were on.
> 3. A search results interface that can display multiple methods on the same type with the same name, when appropriate OR a disambiguation landing section on item pages?
>
> For reviewers: it can be hard to see the new fragment format in action since it immediately gets rewritten to the numbered form.

20 files changed, 350 insertions, 63 deletions

diff --git a/src/librustdoc/formats/cache.rs b/src/librustdoc/formats/cache.rs
index 4c6e7dfb987..b916baecc14 100644
--- a/src/librustdoc/formats/cache.rs
+++ b/src/librustdoc/formats/cache.rs
@@ -223,17 +223,16 @@ impl<'a, 'tcx> DocFolder for CacheBuilder<'a, 'tcx> {
 
         // If the impl is from a masked crate or references something from a
         // masked crate then remove it completely.
-        if let clean::ImplItem(ref i) = *item.kind {
-            if self.cache.masked_crates.contains(&item.item_id.krate())
+        if let clean::ImplItem(ref i) = *item.kind &&
+            (self.cache.masked_crates.contains(&item.item_id.krate())
                 || i.trait_
                     .as_ref()
                     .map_or(false, |t| self.cache.masked_crates.contains(&t.def_id().krate))
                 || i.for_
                     .def_id(self.cache)
-                    .map_or(false, |d| self.cache.masked_crates.contains(&d.krate))
-            {
-                return None;
-            }
+                    .map_or(false, |d| self.cache.masked_crates.contains(&d.krate)))
+        {
+            return None;
         }
 
         // Propagate a trait method's documentation to all implementors of the
@@ -334,33 +333,37 @@ impl<'a, 'tcx> DocFolder for CacheBuilder<'a, 'tcx> {
                     // A crate has a module at its root, containing all items,
                     // which should not be indexed. The crate-item itself is
                     // inserted later on when serializing the search-index.
-                    if item.item_id.as_def_id().map_or(false, |idx| !idx.is_crate_root()) {
+                    if item.item_id.as_def_id().map_or(false, |idx| !idx.is_crate_root())
+                        && let ty = item.type_()
+                        && (ty != ItemType::StructField
+                            || u16::from_str_radix(s.as_str(), 10).is_err())
+                    {
                         let desc =
                             short_markdown_summary(&item.doc_value(), &item.link_names(self.cache));
-                        let ty = item.type_();
-                        if ty != ItemType::StructField
-                            || u16::from_str_radix(s.as_str(), 10).is_err()
-                        {
-                            // In case this is a field from a tuple struct, we don't add it into
-                            // the search index because its name is something like "0", which is
-                            // not useful for rustdoc search.
-                            self.cache.search_index.push(IndexItem {
-                                ty,
-                                name: s,
-                                path: join_with_double_colon(path),
-                                desc,
-                                parent,
-                                parent_idx: None,
-                                search_type: get_function_type_for_search(
-                                    &item,
-                                    self.tcx,
-                                    clean_impl_generics(self.cache.parent_stack.last()).as_ref(),
-                                    self.cache,
-                                ),
-                                aliases: item.attrs.get_doc_aliases(),
-                                deprecation: item.deprecation(self.tcx),
-                            });
-                        }
+                        // In case this is a field from a tuple struct, we don't add it into
+                        // the search index because its name is something like "0", which is
+                        // not useful for rustdoc search.
+                        self.cache.search_index.push(IndexItem {
+                            ty,
+                            name: s,
+                            path: join_with_double_colon(path),
+                            desc,
+                            parent,
+                            parent_idx: None,
+                            impl_id: if let Some(ParentStackItem::Impl { item_id, .. }) = self.cache.parent_stack.last() {
+                                item_id.as_def_id()
+                            } else {
+                                None
+                            },
+                            search_type: get_function_type_for_search(
+                                &item,
+                                self.tcx,
+                                clean_impl_generics(self.cache.parent_stack.last()).as_ref(),
+                                self.cache,
+                            ),
+                            aliases: item.attrs.get_doc_aliases(),
+                            deprecation: item.deprecation(self.tcx),
+                        });
                     }
                 }
                 (Some(parent), None) if is_inherent_impl_item => {
@@ -371,6 +374,13 @@ impl<'a, 'tcx> DocFolder for CacheBuilder<'a, 'tcx> {
                         parent,
                         item: item.clone(),
                         impl_generics,
+                        impl_id: if let Some(ParentStackItem::Impl { item_id, .. }) =
+                            self.cache.parent_stack.last()
+                        {
+                            item_id.as_def_id()
+                        } else {
+                            None
+                        },
                     });
                 }
                 _ => {}
@@ -541,6 +551,7 @@ impl<'a, 'tcx> DocFolder for CacheBuilder<'a, 'tcx> {
 
 pub(crate) struct OrphanImplItem {
     pub(crate) parent: DefId,
+    pub(crate) impl_id: Option<DefId>,
     pub(crate) item: clean::Item,
     pub(crate) impl_generics: Option<(clean::Type, clean::Generics)>,
 }
diff --git a/src/librustdoc/html/render/mod.rs b/src/librustdoc/html/render/mod.rs
index 3e671a64b54..b0ce475850c 100644
--- a/src/librustdoc/html/render/mod.rs
+++ b/src/librustdoc/html/render/mod.rs
@@ -54,7 +54,7 @@ use rustc_data_structures::fx::{FxHashMap, FxHashSet};
 use rustc_hir::def_id::{DefId, DefIdSet};
 use rustc_hir::Mutability;
 use rustc_middle::middle::stability;
-use rustc_middle::ty::TyCtxt;
+use rustc_middle::ty::{self, TyCtxt};
 use rustc_span::{
     symbol::{sym, Symbol},
     BytePos, FileName, RealFileName,
@@ -102,6 +102,7 @@ pub(crate) struct IndexItem {
     pub(crate) desc: String,
     pub(crate) parent: Option<DefId>,
     pub(crate) parent_idx: Option<isize>,
+    pub(crate) impl_id: Option<DefId>,
     pub(crate) search_type: Option<IndexItemFunctionType>,
     pub(crate) aliases: Box<[Symbol]>,
     pub(crate) deprecation: Option<Deprecation>,
@@ -1877,7 +1878,7 @@ pub(crate) fn render_impl_summary(
     aliases: &[String],
 ) {
     let inner_impl = i.inner_impl();
-    let id = cx.derive_id(get_id_for_impl(&inner_impl.for_, inner_impl.trait_.as_ref(), cx));
+    let id = cx.derive_id(get_id_for_impl(cx.tcx(), i.impl_item.item_id));
     let aliases = if aliases.is_empty() {
         String::new()
     } else {
@@ -1994,21 +1995,35 @@ pub(crate) fn small_url_encode(s: String) -> String {
     }
 }
 
-fn get_id_for_impl(for_: &clean::Type, trait_: Option<&clean::Path>, cx: &Context<'_>) -> String {
-    match trait_ {
-        Some(t) => small_url_encode(format!("impl-{:#}-for-{:#}", t.print(cx), for_.print(cx))),
-        None => small_url_encode(format!("impl-{:#}", for_.print(cx))),
-    }
+fn get_id_for_impl<'tcx>(tcx: TyCtxt<'tcx>, impl_id: ItemId) -> String {
+    use rustc_middle::ty::print::with_forced_trimmed_paths;
+    let (type_, trait_) = match impl_id {
+        ItemId::Auto { trait_, for_ } => {
+            let ty = tcx.type_of(for_).skip_binder();
+            (ty, Some(ty::TraitRef::new(tcx, trait_, [ty])))
+        }
+        ItemId::Blanket { impl_id, .. } | ItemId::DefId(impl_id) => {
+            match tcx.impl_subject(impl_id).skip_binder() {
+                ty::ImplSubject::Trait(trait_ref) => {
+                    (trait_ref.args[0].expect_ty(), Some(trait_ref))
+                }
+                ty::ImplSubject::Inherent(ty) => (ty, None),
+            }
+        }
+    };
+    with_forced_trimmed_paths!(small_url_encode(if let Some(trait_) = trait_ {
+        format!("impl-{trait_}-for-{type_}", trait_ = trait_.print_only_trait_path())
+    } else {
+        format!("impl-{type_}")
+    }))
 }
 
 fn extract_for_impl_name(item: &clean::Item, cx: &Context<'_>) -> Option<(String, String)> {
     match *item.kind {
-        clean::ItemKind::ImplItem(ref i) => {
-            i.trait_.as_ref().map(|trait_| {
-                // Alternative format produces no URLs,
-                // so this parameter does nothing.
-                (format!("{:#}", i.for_.print(cx)), get_id_for_impl(&i.for_, Some(trait_), cx))
-            })
+        clean::ItemKind::ImplItem(ref i) if i.trait_.is_some() => {
+            // Alternative format produces no URLs,
+            // so this parameter does nothing.
+            Some((format!("{:#}", i.for_.print(cx)), get_id_for_impl(cx.tcx(), item.item_id)))
         }
         _ => None,
     }
diff --git a/src/librustdoc/html/render/search_index.rs b/src/librustdoc/html/render/search_index.rs
index 78c443b2257..af1dab59496 100644
--- a/src/librustdoc/html/render/search_index.rs
+++ b/src/librustdoc/html/render/search_index.rs
@@ -12,7 +12,7 @@ use crate::formats::cache::{Cache, OrphanImplItem};
 use crate::formats::item_type::ItemType;
 use crate::html::format::join_with_double_colon;
 use crate::html::markdown::short_markdown_summary;
-use crate::html::render::{IndexItem, IndexItemFunctionType, RenderType, RenderTypeId};
+use crate::html::render::{self, IndexItem, IndexItemFunctionType, RenderType, RenderTypeId};
 
 /// Builds the search index from the collected metadata
 pub(crate) fn build_index<'tcx>(
@@ -26,7 +26,8 @@ pub(crate) fn build_index<'tcx>(
 
     // Attach all orphan items to the type's definition if the type
     // has since been learned.
-    for &OrphanImplItem { parent, ref item, ref impl_generics } in &cache.orphan_impl_items {
+    for &OrphanImplItem { impl_id, parent, ref item, ref impl_generics } in &cache.orphan_impl_items
+    {
         if let Some((fqp, _)) = cache.paths.get(&parent) {
             let desc = short_markdown_summary(&item.doc_value(), &item.link_names(cache));
             cache.search_index.push(IndexItem {
@@ -36,6 +37,7 @@ pub(crate) fn build_index<'tcx>(
                 desc,
                 parent: Some(parent),
                 parent_idx: None,
+                impl_id,
                 search_type: get_function_type_for_search(item, tcx, impl_generics.as_ref(), cache),
                 aliases: item.attrs.get_doc_aliases(),
                 deprecation: item.deprecation(tcx),
@@ -222,6 +224,29 @@ pub(crate) fn build_index<'tcx>(
         })
         .collect();
 
+    // Find associated items that need disambiguators
+    let mut associated_item_duplicates = FxHashMap::<(isize, ItemType, Symbol), usize>::default();
+
+    for &item in &crate_items {
+        if item.impl_id.is_some() && let Some(parent_idx) = item.parent_idx {
+            let count = associated_item_duplicates
+                .entry((parent_idx, item.ty, item.name))
+                .or_insert(0);
+            *count += 1;
+        }
+    }
+
+    let associated_item_disambiguators = crate_items
+        .iter()
+        .enumerate()
+        .filter_map(|(index, item)| {
+            let impl_id = ItemId::DefId(item.impl_id?);
+            let parent_idx = item.parent_idx?;
+            let count = *associated_item_duplicates.get(&(parent_idx, item.ty, item.name))?;
+            if count > 1 { Some((index, render::get_id_for_impl(tcx, impl_id))) } else { None }
+        })
+        .collect::<Vec<_>>();
+
     struct CrateData<'a> {
         doc: String,
         items: Vec<&'a IndexItem>,
@@ -230,6 +255,8 @@ pub(crate) fn build_index<'tcx>(
         //
         // To be noted: the `usize` elements are indexes to `items`.
         aliases: &'a BTreeMap<String, Vec<usize>>,
+        // Used when a type has more than one impl with an associated item with the same name.
+        associated_item_disambiguators: &'a Vec<(usize, String)>,
     }
 
     struct Paths {
@@ -382,6 +409,7 @@ pub(crate) fn build_index<'tcx>(
             crate_data.serialize_field("f", &functions)?;
             crate_data.serialize_field("c", &deprecated)?;
             crate_data.serialize_field("p", &paths)?;
+            crate_data.serialize_field("b", &self.associated_item_disambiguators)?;
             if has_aliases {
                 crate_data.serialize_field("a", &self.aliases)?;
             }
@@ -398,6 +426,7 @@ pub(crate) fn build_index<'tcx>(
             items: crate_items,
             paths: crate_paths,
             aliases: &aliases,
+            associated_item_disambiguators: &associated_item_disambiguators,
         })
         .expect("failed serde conversion")
         // All these `replace` calls are because we have to go through JS string for JSON content.
diff --git a/src/librustdoc/html/render/sidebar.rs b/src/librustdoc/html/render/sidebar.rs
index 76f63c6f63e..3f8b22050c8 100644
--- a/src/librustdoc/html/render/sidebar.rs
+++ b/src/librustdoc/html/render/sidebar.rs
@@ -503,8 +503,7 @@ fn sidebar_render_assoc_items(
             .iter()
             .filter_map(|it| {
                 let trait_ = it.inner_impl().trait_.as_ref()?;
-                let encoded =
-                    id_map.derive(super::get_id_for_impl(&it.inner_impl().for_, Some(trait_), cx));
+                let encoded = id_map.derive(super::get_id_for_impl(cx.tcx(), it.impl_item.item_id));
 
                 let prefix = match it.inner_impl().polarity {
                     ty::ImplPolarity::Positive | ty::ImplPolarity::Reservation => "",
diff --git a/src/librustdoc/html/static/js/main.js b/src/librustdoc/html/static/js/main.js
index eb256455b08..43c4f2b6ff5 100644
--- a/src/librustdoc/html/static/js/main.js
+++ b/src/librustdoc/html/static/js/main.js
@@ -354,6 +354,34 @@ function preLoadCss(cssUrl) {
                 expandSection(pageId);
             }
         }
+        if (savedHash.startsWith("impl-")) {
+            // impl-disambiguated links, used by the search engine
+            // format: impl-X[-for-Y]/method.WHATEVER
+            // turn this into method.WHATEVER[-NUMBER]
+            const splitAt = savedHash.indexOf("/");
+            if (splitAt !== -1) {
+                const implId = savedHash.slice(0, splitAt);
+                const assocId = savedHash.slice(splitAt + 1);
+                const implElem = document.getElementById(implId);
+                if (implElem && implElem.parentElement.tagName === "SUMMARY" &&
+                    implElem.parentElement.parentElement.tagName === "DETAILS") {
+                    onEachLazy(implElem.parentElement.parentElement.querySelectorAll(
+                        `[id^="${assocId}"]`),
+                        item => {
+                            const numbered = /([^-]+)-([0-9]+)/.exec(item.id);
+                            if (item.id === assocId || (numbered && numbered[1] === assocId)) {
+                                openParentDetails(item);
+                                item.scrollIntoView();
+                                // Let the section expand itself before trying to highlight
+                                setTimeout(() => {
+                                    window.location.replace("#" + item.id);
+                                }, 0);
+                            }
+                        }
+                    );
+                }
+            }
+        }
     }
 
     function onHashChange(ev) {
diff --git a/src/librustdoc/html/static/js/search.js b/src/librustdoc/html/static/js/search.js
index 7a282a99e9c..48c9a53a283 100644
--- a/src/librustdoc/html/static/js/search.js
+++ b/src/librustdoc/html/static/js/search.js
@@ -1752,6 +1752,7 @@ function initSearch(rawSearchIndex) {
                 type: item.type,
                 is_alias: true,
                 deprecated: item.deprecated,
+                implDisambiguator: item.implDisambiguator,
             };
         }
 
@@ -2218,7 +2219,7 @@ function initSearch(rawSearchIndex) {
             href = ROOT_PATH + name + "/index.html";
         } else if (item.parent !== undefined) {
             const myparent = item.parent;
-            let anchor = "#" + type + "." + name;
+            let anchor = type + "." + name;
             const parentType = itemTypes[myparent.ty];
             let pageType = parentType;
             let pageName = myparent.name;
@@ -2232,16 +2233,19 @@ function initSearch(rawSearchIndex) {
                 const enumName = item.path.substr(enumNameIdx + 2);
                 path = item.path.substr(0, enumNameIdx);
                 displayPath = path + "::" + enumName + "::" + myparent.name + "::";
-                anchor = "#variant." + myparent.name + ".field." + name;
+                anchor = "variant." + myparent.name + ".field." + name;
                 pageType = "enum";
                 pageName = enumName;
             } else {
                 displayPath = path + "::" + myparent.name + "::";
             }
+            if (item.implDisambiguator !== null) {
+                anchor = item.implDisambiguator + "/" + anchor;
+            }
             href = ROOT_PATH + path.replace(/::/g, "/") +
                 "/" + pageType +
                 "." + pageName +
-                ".html" + anchor;
+                ".html#" + anchor;
         } else {
             displayPath = item.path + "::";
             href = ROOT_PATH + item.path.replace(/::/g, "/") +
@@ -2727,6 +2731,10 @@ ${item.displayPath}<span class="${type}">${name}</span>\
              * Types are also represented as arrays; the first item is an index into the `p`
              * array, while the second is a list of types representing any generic parameters.
              *
+             * b[i] contains an item's impl disambiguator. This is only present if an item
+             * is defined in an impl block and, the impl block's type has more than one associated
+             * item with the same name.
+             *
              * `a` defines aliases with an Array of pairs: [name, offset], where `offset`
              * points into the n/t/d/q/i/f arrays.
              *
@@ -2746,6 +2754,7 @@ ${item.displayPath}<span class="${type}">${name}</span>\
              *   i: Array<Number>,
              *   f: Array<RawFunctionSearchType>,
              *   p: Array<Object>,
+             *   b: Array<[Number, String]>,
              *   c: Array<Number>
              * }}
              */
@@ -2766,6 +2775,7 @@ ${item.displayPath}<span class="${type}">${name}</span>\
                 id: id,
                 normalizedName: crate.indexOf("_") === -1 ? crate : crate.replace(/_/g, ""),
                 deprecated: null,
+                implDisambiguator: null,
             };
             id += 1;
             searchIndex.push(crateRow);
@@ -2789,6 +2799,8 @@ ${item.displayPath}<span class="${type}">${name}</span>\
             const itemFunctionSearchTypes = crateCorpus.f;
             // an array of (Number) indices for the deprecated items
             const deprecatedItems = new Set(crateCorpus.c);
+            // an array of (Number) indices for the deprecated items
+            const implDisambiguator = new Map(crateCorpus.b);
             // an array of [(Number) item type,
             //              (String) name]
             const paths = crateCorpus.p;
@@ -2849,6 +2861,7 @@ ${item.displayPath}<span class="${type}">${name}</span>\
                     id: id,
                     normalizedName: word.indexOf("_") === -1 ? word : word.replace(/_/g, ""),
                     deprecated: deprecatedItems.has(i),
+                    implDisambiguator: implDisambiguator.has(i) ? implDisambiguator.get(i) : null,
                 };
                 id += 1;
                 searchIndex.push(row);
diff --git a/tests/rustdoc-gui/search-result-impl-disambiguation.goml b/tests/rustdoc-gui/search-result-impl-disambiguation.goml
new file mode 100644
index 00000000000..6d12032e891
--- /dev/null
+++ b/tests/rustdoc-gui/search-result-impl-disambiguation.goml
@@ -0,0 +1,43 @@
+// ignore-tidy-linelength
+
+// Checks that, if a type has two methods with the same name, they both get
+// linked correctly.
+go-to: "file://" + |DOC_PATH| + "/test_docs/index.html"
+
+// This should link to the inherent impl
+write: (".search-input", "ZyxwvutMethodDisambiguation -> bool")
+// To be SURE that the search will be run.
+press-key: 'Enter'
+// Waiting for the search results to appear...
+wait-for: "#search-tabs"
+// Check the disambiguated link.
+assert-count: ("a.result-method", 1)
+assert-attribute: ("a.result-method", {
+    "href": "../test_docs/struct.ZyxwvutMethodDisambiguation.html#impl-ZyxwvutMethodDisambiguation/method.method_impl_disambiguation"
+})
+click: "a.result-method"
+wait-for: "#impl-ZyxwvutMethodDisambiguation"
+assert-document-property: ({
+    "URL": "struct.ZyxwvutMethodDisambiguation.html#method.method_impl_disambiguation"
+}, ENDS_WITH)
+assert: "section:target"
+
+go-to: "file://" + |DOC_PATH| + "/test_docs/index.html"
+
+// This should link to the trait impl
+write: (".search-input", "ZyxwvutMethodDisambiguation, usize -> usize")
+// To be SURE that the search will be run.
+press-key: 'Enter'
+// Waiting for the search results to appear...
+wait-for: "#search-tabs"
+// Check the disambiguated link.
+assert-count: ("a.result-method", 1)
+assert-attribute: ("a.result-method", {
+    "href": "../test_docs/struct.ZyxwvutMethodDisambiguation.html#impl-ZyxwvutTrait-for-ZyxwvutMethodDisambiguation/method.method_impl_disambiguation"
+})
+click: "a.result-method"
+wait-for: "#impl-ZyxwvutMethodDisambiguation"
+assert-document-property: ({
+    "URL": "struct.ZyxwvutMethodDisambiguation.html#method.method_impl_disambiguation-1"
+}, ENDS_WITH)
+assert: "section:target"
diff --git a/tests/rustdoc-gui/src/test_docs/lib.rs b/tests/rustdoc-gui/src/test_docs/lib.rs
index 38180aef762..5c91bcbb4ee 100644
--- a/tests/rustdoc-gui/src/test_docs/lib.rs
+++ b/tests/rustdoc-gui/src/test_docs/lib.rs
@@ -529,3 +529,21 @@ pub mod cfgs {
     /// Some docs.
     pub mod cfgs {}
 }
+
+pub struct ZyxwvutMethodDisambiguation;
+
+impl ZyxwvutMethodDisambiguation {
+    pub fn method_impl_disambiguation(&self) -> bool {
+        true
+    }
+}
+
+pub trait ZyxwvutTrait {
+    fn method_impl_disambiguation(&self, x: usize) -> usize;
+}
+
+impl ZyxwvutTrait for ZyxwvutMethodDisambiguation {
+    fn method_impl_disambiguation(&self, x: usize) -> usize {
+        x
+    }
+}
diff --git a/tests/rustdoc-js-std/simd-type-signatures.js b/tests/rustdoc-js-std/simd-type-signatures.js
new file mode 100644
index 00000000000..5c7cf372bce
--- /dev/null
+++ b/tests/rustdoc-js-std/simd-type-signatures.js
@@ -0,0 +1,70 @@
+// exact-check
+// ignore-order
+// ignore-tidy-linelength
+
+// This test case verifies that the href points at the correct impl
+
+const FILTER_CRATE = "std";
+
+const EXPECTED = [
+    {
+        'query': 'simd<i16>, simd<i16> -> simd<i16>',
+        'others': [
+            {
+                'path': 'std::simd::prelude::Simd',
+                'name': 'simd_max',
+                'href': '../std/simd/prelude/struct.Simd.html#impl-SimdOrd-for-Simd%3Ci16,+LANES%3E/method.simd_max'
+            },
+            {
+                'path': 'std::simd::prelude::Simd',
+                'name': 'simd_min',
+                'href': '../std/simd/prelude/struct.Simd.html#impl-SimdOrd-for-Simd%3Ci16,+LANES%3E/method.simd_min'
+            },
+            {
+                'path': 'std::simd::prelude::Simd',
+                'name': 'simd_clamp',
+                'href': '../std/simd/prelude/struct.Simd.html#impl-SimdOrd-for-Simd%3Ci16,+LANES%3E/method.simd_clamp'
+            },
+            {
+                'path': 'std::simd::prelude::Simd',
+                'name': 'saturating_add',
+                'href': '../std/simd/prelude/struct.Simd.html#impl-SimdInt-for-Simd%3Ci16,+LANES%3E/method.saturating_add'
+            },
+            {
+                'path': 'std::simd::prelude::Simd',
+                'name': 'saturating_sub',
+                'href': '../std/simd/prelude/struct.Simd.html#impl-SimdInt-for-Simd%3Ci16,+LANES%3E/method.saturating_sub'
+            },
+        ],
+    },
+    {
+        'query': 'simd<i8>, simd<i8> -> simd<i8>',
+        'others': [
+            {
+                'path': 'std::simd::prelude::Simd',
+                'name': 'simd_max',
+                'href': '../std/simd/prelude/struct.Simd.html#impl-SimdOrd-for-Simd%3Ci8,+LANES%3E/method.simd_max'
+            },
+            {
+                'path': 'std::simd::prelude::Simd',
+                'name': 'simd_min',
+                'href': '../std/simd/prelude/struct.Simd.html#impl-SimdOrd-for-Simd%3Ci8,+LANES%3E/method.simd_min'
+            },
+            {
+                'path': 'std::simd::prelude::Simd',
+                'name': 'simd_clamp',
+                'href': '../std/simd/prelude/struct.Simd.html#impl-SimdOrd-for-Simd%3Ci8,+LANES%3E/method.simd_clamp'
+            },
+            {
+                'path': 'std::simd::prelude::Simd',
+                'name': 'saturating_add',
+                'href': '../std/simd/prelude/struct.Simd.html#impl-SimdInt-for-Simd%3Ci8,+LANES%3E/method.saturating_add'
+            },
+            {
+                'path': 'std::simd::prelude::Simd',
+                'name': 'saturating_sub',
+                'href': '../std/simd/prelude/struct.Simd.html#impl-SimdInt-for-Simd%3Ci8,+LANES%3E/method.saturating_sub'
+            },
+        ],
+    },
+];
diff --git a/tests/rustdoc-js/search-method-disambiguate.js b/tests/rustdoc-js/search-method-disambiguate.js
new file mode 100644
index 00000000000..70aa895f994
--- /dev/null
+++ b/tests/rustdoc-js/search-method-disambiguate.js
@@ -0,0 +1,28 @@
+// exact-check
+// ignore-order
+// ignore-tidy-linelength
+
+const FILTER_CRATE = "search_method_disambiguate";
+
+const EXPECTED = [
+    {
+        'query': 'MyTy -> bool',
+        'others': [
+            {
+                'path': 'search_method_disambiguate::MyTy',
+                'name': 'my_method',
+                'href': '../search_method_disambiguate/struct.MyTy.html#impl-X-for-MyTy%3Cbool%3E/method.my_method'
+            },
+        ],
+    },
+    {
+        'query': 'MyTy -> u8',
+        'others': [
+            {
+                'path': 'search_method_disambiguate::MyTy',
+                'name': 'my_method',
+                'href': '../search_method_disambiguate/struct.MyTy.html#impl-X-for-MyTy%3Cu8%3E/method.my_method'
+            },
+        ],
+    }
+];
diff --git a/tests/rustdoc-js/search-method-disambiguate.rs b/tests/rustdoc-js/search-method-disambiguate.rs
new file mode 100644
index 00000000000..ae884447a92
--- /dev/null
+++ b/tests/rustdoc-js/search-method-disambiguate.rs
@@ -0,0 +1,22 @@
+pub trait X {
+    type InnerType;
+    fn my_method(&self) -> Self::InnerType;
+}
+
+pub struct MyTy<T> {
+    pub t: T,
+}
+
+impl X for MyTy<bool> {
+    type InnerType = bool;
+    fn my_method(&self) -> bool {
+        self.t
+    }
+}
+
+impl X for MyTy<u8> {
+    type InnerType = u8;
+    fn my_method(&self) -> u8 {
+        self.t
+    }
+}
diff --git a/tests/rustdoc/blanket-reexport-item.rs b/tests/rustdoc/blanket-reexport-item.rs
index 437f0001fcf..315a38c30c5 100644
--- a/tests/rustdoc/blanket-reexport-item.rs
+++ b/tests/rustdoc/blanket-reexport-item.rs
@@ -1,6 +1,6 @@
 #![crate_name = "foo"]
 
-// @has foo/struct.S.html '//*[@id="impl-Into%3CU%3E-for-S"]//h3[@class="code-header"]' 'impl<T, U> Into<U> for T'
+// @has foo/struct.S.html '//*[@id="impl-Into%3CU%3E-for-T"]//h3[@class="code-header"]' 'impl<T, U> Into<U> for T'
 pub struct S2 {}
 mod m {
     pub struct S {}
diff --git a/tests/rustdoc/const-generics/const-impl.rs b/tests/rustdoc/const-generics/const-impl.rs
index 152b643bf4b..b424ea4b33c 100644
--- a/tests/rustdoc/const-generics/const-impl.rs
+++ b/tests/rustdoc/const-generics/const-impl.rs
@@ -31,7 +31,7 @@ impl<T> VSet<T, { Order::Unsorted }> {
 
 pub struct Escape<const S: &'static str>;
 
-// @has foo/struct.Escape.html '//*[@id="impl-Escape%3Cr%23%22%3Cscript%3Ealert(%22Escape%22);%3C/script%3E%22%23%3E"]/h3[@class="code-header"]' 'impl Escape<r#"<script>alert("Escape");</script>"#>'
+// @has foo/struct.Escape.html '//*[@id="impl-Escape%3C%22%3Cscript%3Ealert(%5C%22Escape%5C%22);%3C/script%3E%22%3E"]/h3[@class="code-header"]' 'impl Escape<r#"<script>alert("Escape");</script>"#>'
 impl Escape<r#"<script>alert("Escape");</script>"#> {
     pub fn f() {}
 }
diff --git a/tests/rustdoc/generic-impl.rs b/tests/rustdoc/generic-impl.rs
index 6f68b157499..f62540c6bf9 100644
--- a/tests/rustdoc/generic-impl.rs
+++ b/tests/rustdoc/generic-impl.rs
@@ -5,9 +5,9 @@ use std::fmt;
 // @!has foo/struct.Bar.html '//*[@id="impl-ToString-for-Bar"]' ''
 pub struct Bar;
 
-// @has foo/struct.Foo.html '//*[@id="impl-ToString-for-Foo"]//h3[@class="code-header"]' 'impl<T> ToString for T'
+// @has foo/struct.Foo.html '//*[@id="impl-ToString-for-T"]//h3[@class="code-header"]' 'impl<T> ToString for T'
 pub struct Foo;
-// @has foo/struct.Foo.html '//*[@class="sidebar-elems"]//section//a[@href="#impl-ToString-for-Foo"]' 'ToString'
+// @has foo/struct.Foo.html '//*[@class="sidebar-elems"]//section//a[@href="#impl-ToString-for-T"]' 'ToString'
 
 impl fmt::Display for Foo {
     fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
diff --git a/tests/rustdoc/issue-32077-type-alias-impls.rs b/tests/rustdoc/issue-32077-type-alias-impls.rs
index ac486c36ad0..664b678093e 100644
--- a/tests/rustdoc/issue-32077-type-alias-impls.rs
+++ b/tests/rustdoc/issue-32077-type-alias-impls.rs
@@ -22,7 +22,7 @@ impl Bar for GenericStruct<u32> {}
 // We check that "Aliased type" is also present as a title in the sidebar.
 // @has - '//*[@class="sidebar-elems"]//h3/a[@href="#aliased-type"]' 'Aliased type'
 // We check that we have the implementation of the type alias itself.
-// @has - '//*[@id="impl-TypedefStruct"]/h3' 'impl TypedefStruct'
+// @has - '//*[@id="impl-GenericStruct%3Cu8%3E"]/h3' 'impl TypedefStruct'
 // @has - '//*[@id="method.on_alias"]/h4' 'pub fn on_alias()'
 // @has - '//*[@id="impl-GenericStruct%3CT%3E"]/h3' 'impl<T> GenericStruct<T>'
 // @has - '//*[@id="method.on_gen"]/h4' 'pub fn on_gen(arg: T)'
diff --git a/tests/rustdoc/issue-78701.rs b/tests/rustdoc/issue-78701.rs
index e3e46468f38..3f1638d5ffc 100644
--- a/tests/rustdoc/issue-78701.rs
+++ b/tests/rustdoc/issue-78701.rs
@@ -6,7 +6,7 @@
 
 // @has 'foo/struct.AnotherStruct.html'
 // @count - '//*[@class="sidebar"]//a[@href="#impl-AnAmazingTrait-for-AnotherStruct%3C()%3E"]' 1
-// @count - '//*[@class="sidebar"]//a[@href="#impl-AnAmazingTrait-for-AnotherStruct%3CT%3E"]' 1
+// @count - '//*[@class="sidebar"]//a[@href="#impl-AnAmazingTrait-for-T"]' 1
 
 pub trait Something {}
 
diff --git a/tests/rustdoc/primitive/primitive-generic-impl.rs b/tests/rustdoc/primitive/primitive-generic-impl.rs
index 2da8ae6ff38..558336d7316 100644
--- a/tests/rustdoc/primitive/primitive-generic-impl.rs
+++ b/tests/rustdoc/primitive/primitive-generic-impl.rs
@@ -1,7 +1,7 @@
 #![feature(rustc_attrs)]
 #![crate_name = "foo"]
 
-// @has foo/primitive.i32.html '//*[@id="impl-ToString-for-i32"]//h3[@class="code-header"]' 'impl<T> ToString for T'
+// @has foo/primitive.i32.html '//*[@id="impl-ToString-for-T"]//h3[@class="code-header"]' 'impl<T> ToString for T'
 
 #[rustc_doc_primitive = "i32"]
 /// Some useless docs, wouhou!
diff --git a/tests/rustdoc/sidebar-links-to-foreign-impl.rs b/tests/rustdoc/sidebar-links-to-foreign-impl.rs
index caa17dfbb1c..733a18ad94a 100644
--- a/tests/rustdoc/sidebar-links-to-foreign-impl.rs
+++ b/tests/rustdoc/sidebar-links-to-foreign-impl.rs
@@ -7,8 +7,8 @@
 // @has - '//h2[@id="foreign-impls"]' 'Implementations on Foreign Types'
 // @has - '//*[@class="sidebar-elems"]//section//a[@href="#impl-Foo-for-u32"]' 'u32'
 // @has - '//*[@id="impl-Foo-for-u32"]//h3[@class="code-header"]' 'impl Foo for u32'
-// @has - "//*[@class=\"sidebar-elems\"]//section//a[@href=\"#impl-Foo-for-%26'a+str\"]" "&'a str"
-// @has - "//*[@id=\"impl-Foo-for-%26'a+str\"]//h3[@class=\"code-header\"]" "impl<'a> Foo for &'a str"
+// @has - "//*[@class=\"sidebar-elems\"]//section//a[@href=\"#impl-Foo-for-%26str\"]" "&'a str"
+// @has - "//*[@id=\"impl-Foo-for-%26str\"]//h3[@class=\"code-header\"]" "impl<'a> Foo for &'a str"
 pub trait Foo {}
 
 impl Foo for u32 {}
diff --git a/tests/rustdoc/src-links-auto-impls.rs b/tests/rustdoc/src-links-auto-impls.rs
index 1c8d1573192..08a497d4cf5 100644
--- a/tests/rustdoc/src-links-auto-impls.rs
+++ b/tests/rustdoc/src-links-auto-impls.rs
@@ -5,8 +5,8 @@
 // @!has - '//*[@id="impl-Sized-for-Unsized"]//a[@class="src"]' 'source'
 // @has - '//*[@id="impl-Sync-for-Unsized"]/h3[@class="code-header"]' 'impl Sync for Unsized'
 // @!has - '//*[@id="impl-Sync-for-Unsized"]//a[@class="src"]' 'source'
-// @has - '//*[@id="impl-Any-for-Unsized"]/h3[@class="code-header"]' 'impl<T> Any for T'
-// @has - '//*[@id="impl-Any-for-Unsized"]//a[@class="src rightside"]' 'source'
+// @has - '//*[@id="impl-Any-for-T"]/h3[@class="code-header"]' 'impl<T> Any for T'
+// @has - '//*[@id="impl-Any-for-T"]//a[@class="src rightside"]' 'source'
 pub struct Unsized {
     data: [u8],
 }
diff --git a/tests/rustdoc/where-clause-order.rs b/tests/rustdoc/where-clause-order.rs
index b10f8f6856e..7261dfa7dd9 100644
--- a/tests/rustdoc/where-clause-order.rs
+++ b/tests/rustdoc/where-clause-order.rs
@@ -7,7 +7,7 @@ where
 }
 
 // @has 'foo/trait.SomeTrait.html'
-// @has - "//*[@id='impl-SomeTrait%3C(A,+B,+C,+D,+E)%3E-for-(A,+B,+C,+D,+E)']/h3" "impl<A, B, C, D, E> SomeTrait<(A, B, C, D, E)> for (A, B, C, D, E)where A: PartialOrd<A> + PartialEq<A>, B: PartialOrd<B> + PartialEq<B>, C: PartialOrd<C> + PartialEq<C>, D: PartialOrd<D> + PartialEq<D>, E: PartialOrd<E> + PartialEq<E> + ?Sized, "
+// @has - "//*[@id='impl-SomeTrait-for-(A,+B,+C,+D,+E)']/h3" "impl<A, B, C, D, E> SomeTrait<(A, B, C, D, E)> for (A, B, C, D, E)where A: PartialOrd<A> + PartialEq<A>, B: PartialOrd<B> + PartialEq<B>, C: PartialOrd<C> + PartialEq<C>, D: PartialOrd<D> + PartialEq<D>, E: PartialOrd<E> + PartialEq<E> + ?Sized, "
 impl<A, B, C, D, E> SomeTrait<(A, B, C, D, E)> for (A, B, C, D, E)
 where
     A: PartialOrd<A> + PartialEq<A>,
@@ -17,3 +17,14 @@ where
     E: PartialOrd<E> + PartialEq<E> + ?Sized,
 {
 }
+
+// @has - "//*[@id='impl-SomeTrait%3C(A,+B,+C,+D)%3E-for-(A,+B,+C,+D,+E)']/h3" "impl<A, B, C, D, E> SomeTrait<(A, B, C, D)> for (A, B, C, D, E)where A: PartialOrd<A> + PartialEq<A>, B: PartialOrd<B> + PartialEq<B>, C: PartialOrd<C> + PartialEq<C>, D: PartialOrd<D> + PartialEq<D>, E: PartialOrd<E> + PartialEq<E> + ?Sized, "
+impl<A, B, C, D, E> SomeTrait<(A, B, C, D)> for (A, B, C, D, E)
+where
+    A: PartialOrd<A> + PartialEq<A>,
+    B: PartialOrd<B> + PartialEq<B>,
+    C: PartialOrd<C> + PartialEq<C>,
+    D: PartialOrd<D> + PartialEq<D>,
+    E: PartialOrd<E> + PartialEq<E> + ?Sized,
+{
+}