Compute more mathematically well-rounded notion of transitive deps

By including the crate itself, we make the resulting set closed with
respect to `transitve_reveres_dependencies` operation, as it becomes a
proper transitive closure. This just feels more proper and mathy.

And, indeed, this actually allows us to simplify call sites somewhat.

1 files changed, 3 insertions, 1 deletions

diff --git a/crates/base_db/src/input.rs b/crates/base_db/src/input.rs
index e9e8dfc2e..248ab1de2 100644
--- a/crates/base_db/src/input.rs
+++ b/crates/base_db/src/input.rs
@@ -274,13 +274,15 @@ impl CrateGraph {
         deps.into_iter()
     }
 
-    /// Returns an iterator over all transitive reverse dependencies of the given crate.
+    /// Returns all transitive reverse dependencies of the given crate,
+    /// including the crate itself.
     pub fn transitive_reverse_dependencies(
         &self,
         of: CrateId,
     ) -> impl Iterator<Item = CrateId> + '_ {
         let mut worklist = vec![of];
         let mut rev_deps = FxHashSet::default();
+        rev_deps.insert(of);
         let mut inverted_graph = FxHashMap::<_, Vec<_>>::default();
         self.arena.iter().for_each(|(&krate, data)| {
             data.dependencies