Ensure resolved hint's file exists

Author: SomeoneToIgnore

crates/rust-analyzer/src/global_state.rs

@@ -473,6 +473,10 @@ impl GlobalStateSnapshot {
     pub(crate) fn vfs_memory_usage(&self) -> usize {
         self.vfs.read().0.memory_usage()
     }
+
+    pub(crate) fn file_exists(&self, file_id: FileId) -> bool {
+        self.vfs.read().0.exists(file_id)
+    }
 }
 
 pub(crate) fn file_id_to_url(vfs: &vfs::Vfs, id: FileId) -> Url {

crates/rust-analyzer/src/handlers/request.rs

@@ -1436,6 +1436,8 @@ pub(crate) fn handle_inlay_hints_resolve(
 
     let resolve_data: lsp_ext::InlayHintResolveData = serde_json::from_value(data)?;
     let file_id = FileId(resolve_data.file_id);
+    anyhow::ensure!(snap.file_exists(file_id), "Invalid LSP resolve data");
+
     let line_index = snap.file_line_index(file_id)?;
     let range = from_proto::text_range(
         &line_index,

crates/vfs/src/lib.rs

@@ -184,6 +184,11 @@ impl Vfs {
         mem::take(&mut self.changes)
     }
 
+    /// Provides a panic-less way to verify file_id validity.
+    pub fn exists(&self, file_id: FileId) -> bool {
+        self.get(file_id).is_some()
+    }
+
     /// Returns the id associated with `path`
     ///
     /// - If `path` does not exists in the `Vfs`, allocate a new id for it, associated with a