Only populate prelude for crate-level DefMaps

crates/hir_def/src/nameres/collector.rs

@@ -54,6 +54,7 @@ pub(super) fn collect_defs(
 ) -> DefMap {
     let crate_graph = db.crate_graph();
 
+    if block.is_none() {
         // populate external prelude
         for dep in &crate_graph[def_map.krate].dependencies {
             log::debug!("crate dep {:?} -> {:?}", dep.name, dep.crate_id);
@@ -70,6 +71,7 @@ pub(super) fn collect_defs(
                 def_map.prelude = dep_def_map.prelude;
             }
         }
+    }
 
     let cfg_options = &crate_graph[def_map.krate].cfg_options;
     let proc_macros = &crate_graph[def_map.krate].proc_macro;

crates/ide/src/hover.rs

@@ -3897,4 +3897,46 @@ trait A where
             "#]],
         );
     }
+
+    #[test]
+    fn string_shadowed_with_inner_items() {
+        check(
+            r#"
+//- /main.rs crate:main deps:alloc
+
+/// Custom `String` type.
+struct String;
+
+fn f() {
+    let _: String$0;
+
+    fn inner() {}
+}
+
+//- /alloc.rs crate:alloc
+#[prelude_import]
+pub use string::*;
+
+mod string {
+    /// This is `alloc::String`.
+    pub struct String;
+}
+            "#,
+            expect![[r#"
+                *String*
+
+                ```rust
+                main
+                ```
+
+                ```rust
+                struct String
+                ```
+
+                ---
+
+                Custom `String` type.
+            "#]],
+        )
+    }
 }