2 files changed, 40 insertions, 2 deletions

diff --git a/crates/ra_hir/src/module_tree.rs b/crates/ra_hir/src/module_tree.rs
index d1dc3fa4b..893c375b5 100644
--- a/crates/ra_hir/src/module_tree.rs
+++ b/crates/ra_hir/src/module_tree.rs
@@ -172,6 +172,7 @@ impl ModuleTree {
         file_id: HirFileId,
         decl_id: Option<SourceFileItemId>,
     ) -> ModuleId {
+        let is_root = parent.is_none();
         let id = self.alloc_mod(ModuleData {
             file_id,
             decl_id,
@@ -191,7 +192,7 @@ impl ModuleTree {
             });
 
             let (points_to, problem) = if sub.is_declaration {
-                let (points_to, problem) = resolve_submodule(db, file_id, &sub.name);
+                let (points_to, problem) = resolve_submodule(db, file_id, &sub.name, is_root);
                 let points_to = points_to
                     .into_iter()
                     .map(|file_id| {
@@ -295,6 +296,7 @@ fn resolve_submodule(
     db: &impl HirDatabase,
     file_id: HirFileId,
     name: &Name,
+    is_root: bool,
 ) -> (Vec<FileId>, Option<Problem>) {
     // FIXME: handle submodules of inline modules properly
     let file_id = file_id.original_file(db);
@@ -303,7 +305,7 @@ fn resolve_submodule(
     let root = RelativePathBuf::default();
     let dir_path = path.parent().unwrap_or(&root);
     let mod_name = path.file_stem().unwrap_or("unknown");
-    let is_dir_owner = mod_name == "mod" || mod_name == "lib" || mod_name == "main";
+    let is_dir_owner = is_root || mod_name == "mod";
 
     let file_mod = dir_path.join(format!("{}.rs", name));
     let dir_mod = dir_path.join(format!("{}/mod.rs", name));
diff --git a/crates/ra_hir/src/nameres/tests.rs b/crates/ra_hir/src/nameres/tests.rs
index e72781f51..3d420467c 100644
--- a/crates/ra_hir/src/nameres/tests.rs
+++ b/crates/ra_hir/src/nameres/tests.rs
@@ -19,6 +19,20 @@ fn item_map(fixture: &str) -> (Arc<ItemMap>, ModuleId) {
     (db.item_map(krate.crate_id), module_id)
 }
 
+/// Sets the crate root to the file of the cursor marker
+fn item_map_custom_crate_root(fixture: &str) -> (Arc<ItemMap>, ModuleId) {
+    let (mut db, pos) = MockDatabase::with_position(fixture);
+
+    let mut crate_graph = CrateGraph::default();
+    crate_graph.add_crate_root(pos.file_id);
+    db.set_crate_graph(Arc::new(crate_graph));
+
+    let module = crate::source_binder::module_from_position(&db, pos).unwrap();
+    let krate = module.krate(&db).unwrap();
+    let module_id = module.module_id;
+    (db.item_map(krate.crate_id), module_id)
+}
+
 fn check_module_item_map(map: &ItemMap, module_id: ModuleId, expected: &str) {
     let mut lines = map[module_id]
         .items
@@ -134,6 +148,28 @@ fn re_exports() {
 }
 
 #[test]
+fn module_resolution_works_for_non_standard_filenames() {
+    let (item_map, module_id) = item_map_custom_crate_root(
+        "
+        //- /my_library.rs
+        mod foo;
+        use self::foo::Bar;
+        <|>
+        //- /foo/mod.rs
+        pub struct Bar;
+    ",
+    );
+    check_module_item_map(
+        &item_map,
+        module_id,
+        "
+            Bar: t v
+            foo: t
+        ",
+    );
+}
+
+#[test]
 fn name_res_works_for_broken_modules() {
     covers!(name_res_works_for_broken_modules);
     let (item_map, module_id) = item_map(