Rollup merge of rust-lang#148543 - GuillaumeGomez:fix-import_trait_associated_functions, r=lolbinarycat

Correctly link to associated trait items in reexports

Fixes rust-lang#148008.

Issue was that we didn't add anchors in this case.

r? ```@lolbinarycat```

Author: Zalathar

src/librustdoc/html/format.rs

@@ -838,9 +838,23 @@ fn print_higher_ranked_params_with_space(
 pub(crate) fn print_anchor(did: DefId, text: Symbol, cx: &Context<'_>) -> impl Display {
     fmt::from_fn(move |f| {
         if let Ok(HrefInfo { url, kind, rust_path }) = href(did, cx) {
+            let tcx = cx.tcx();
+            let def_kind = tcx.def_kind(did);
+            let anchor = if matches!(
+                def_kind,
+                DefKind::AssocTy | DefKind::AssocFn | DefKind::AssocConst | DefKind::Variant
+            ) {
+                let parent_def_id = tcx.parent(did);
+                let item_type =
+                    ItemType::from_def_kind(def_kind, Some(tcx.def_kind(parent_def_id)));
+                format!("#{}.{}", item_type.as_str(), tcx.item_name(did))
+            } else {
+                String::new()
+            };
+
             write!(
                 f,
-                r#"<a class="{kind}" href="{url}" title="{kind} {path}">{text}</a>"#,
+                r#"<a class="{kind}" href="{url}{anchor}" title="{kind} {path}">{text}</a>"#,
                 path = join_path_syms(rust_path),
                 text = EscapeBodyText(text.as_str()),
             )

tests/rustdoc/import_trait_associated_functions.rs

@@ -0,0 +1,19 @@
+// This test ensures that reexports of associated items links to the associated items.
+// Regression test for <https://github.com/rust-lang/rust/issues/148008>.
+
+#![feature(import_trait_associated_functions)]
+
+#![crate_name = "foo"]
+
+//@ has 'foo/index.html'
+
+pub trait Test {
+    fn method();
+    const CONST: u8;
+    type Type;
+}
+
+//@ has - '//*[@id="reexport.method"]//a[@href="trait.Test.html#tymethod.method"]' 'method'
+//@ has - '//*[@id="reexport.CONST"]//a[@href="trait.Test.html#associatedconstant.CONST"]' 'CONST'
+//@ has - '//*[@id="reexport.Type"]//a[@href="trait.Test.html#associatedtype.Type"]' 'Type'
+pub use self::Test::{method, CONST, Type};