rustdoc: fix caching of intra-doc links on reexports

2 files changed, 25 insertions, 2 deletions

diff --git a/src/librustdoc/clean/types.rs b/src/librustdoc/clean/types.rs
index 782311e593b..26b087feb16 100644
--- a/src/librustdoc/clean/types.rs
+++ b/src/librustdoc/clean/types.rs
@@ -480,10 +480,28 @@ impl Item {
         }
     }
 
+    /// If the item has doc comments from a reexport, returns the item id of that reexport,
+    /// otherwise returns returns the item id.
+    ///
+    /// This is used as a key for caching intra-doc link resolution,
+    /// to prevent two reexports of the same item from using the same cache.
+    pub(crate) fn item_or_reexport_id(&self) -> ItemId {
+        // added documentation on a reexport is always prepended.
+        self.attrs
+            .doc_strings
+            .first()
+            .map(|x| x.item_id)
+            .flatten()
+            .map(ItemId::from)
+            .unwrap_or(self.item_id)
+    }
+
     pub(crate) fn links(&self, cx: &Context<'_>) -> Vec<RenderedLink> {
         use crate::html::format::{href, link_tooltip};
 
-        let Some(links) = cx.cache().intra_doc_links.get(&self.item_id) else { return vec![] };
+        let Some(links) = cx.cache().intra_doc_links.get(&self.item_or_reexport_id()) else {
+            return vec![];
+        };
         links
             .iter()
             .filter_map(|ItemLink { link: s, link_text, page_id: id, fragment }| {
diff --git a/src/librustdoc/passes/collect_intra_doc_links.rs b/src/librustdoc/passes/collect_intra_doc_links.rs
index c9fa3a4837f..bcb676cd1f1 100644
--- a/src/librustdoc/passes/collect_intra_doc_links.rs
+++ b/src/librustdoc/passes/collect_intra_doc_links.rs
@@ -1082,7 +1082,12 @@ impl LinkCollector<'_, '_> {
             for md_link in preprocessed_markdown_links(&doc) {
                 let link = self.resolve_link(&doc, item, item_id, module_id, &md_link);
                 if let Some(link) = link {
-                    self.cx.cache.intra_doc_links.entry(item.item_id).or_default().insert(link);
+                    self.cx
+                        .cache
+                        .intra_doc_links
+                        .entry(item.item_or_reexport_id())
+                        .or_default()
+                        .insert(link);
                 }
             }
         }