From cf6d14cee7fee17ed668f502de5042136446945b Mon Sep 17 00:00:00 2001
From: Jeremy Kolb <kjeremy@gmail.com>
Date: Sun, 9 Aug 2020 16:27:48 -0400
Subject: [PATCH] Return InvalidRequest if Shutdown has been requested

From the LSP 3.16 spec: "If a server receives requests after a shutdown request those requests should error with InvalidRequest."
---
 crates/rust-analyzer/src/global_state.rs |  2 ++
 crates/rust-analyzer/src/main_loop.rs    | 15 ++++++++++++++-
 2 files changed, 16 insertions(+), 1 deletion(-)

diff --git a/crates/rust-analyzer/src/global_state.rs b/crates/rust-analyzer/src/global_state.rs
index 0e592ac1bea..658a50d1507 100644
--- a/crates/rust-analyzer/src/global_state.rs
+++ b/crates/rust-analyzer/src/global_state.rs
@@ -73,6 +73,7 @@ pub(crate) struct GlobalState {
     pub(crate) mem_docs: FxHashMap<VfsPath, DocumentData>,
     pub(crate) semantic_tokens_cache: Arc<Mutex<FxHashMap<Url, SemanticTokens>>>,
     pub(crate) vfs: Arc<RwLock<(vfs::Vfs, FxHashMap<FileId, LineEndings>)>>,
+    pub(crate) shutdown_requested: bool,
     pub(crate) status: Status,
     pub(crate) source_root_config: SourceRootConfig,
     pub(crate) proc_macro_client: ProcMacroClient,
@@ -124,6 +125,7 @@ impl GlobalState {
             mem_docs: FxHashMap::default(),
             semantic_tokens_cache: Arc::new(Default::default()),
             vfs: Arc::new(RwLock::new((vfs::Vfs::default(), FxHashMap::default()))),
+            shutdown_requested: false,
             status: Status::default(),
             source_root_config: SourceRootConfig::default(),
             proc_macro_client: ProcMacroClient::dummy(),
diff --git a/crates/rust-analyzer/src/main_loop.rs b/crates/rust-analyzer/src/main_loop.rs
index 0ac6434dd79..e6cf46df23e 100644
--- a/crates/rust-analyzer/src/main_loop.rs
+++ b/crates/rust-analyzer/src/main_loop.rs
@@ -337,6 +337,16 @@ impl GlobalState {
     fn on_request(&mut self, request_received: Instant, req: Request) -> Result<()> {
         self.register_request(&req, request_received);
 
+        if self.shutdown_requested {
+            self.respond(Response::new_err(
+                req.id,
+                lsp_server::ErrorCode::InvalidRequest as i32,
+                "Shutdown already requested.".to_owned(),
+            ));
+
+            return Ok(());
+        }
+
         if self.status == Status::Loading && req.method != "shutdown" {
             self.respond(lsp_server::Response::new_err(
                 req.id,
@@ -351,7 +361,10 @@ impl GlobalState {
             .on_sync::<lsp_ext::ReloadWorkspace>(|s, ()| Ok(s.fetch_workspaces()))?
             .on_sync::<lsp_ext::JoinLines>(|s, p| handlers::handle_join_lines(s.snapshot(), p))?
             .on_sync::<lsp_ext::OnEnter>(|s, p| handlers::handle_on_enter(s.snapshot(), p))?
-            .on_sync::<lsp_types::request::Shutdown>(|_, ()| Ok(()))?
+            .on_sync::<lsp_types::request::Shutdown>(|s, ()| {
+                s.shutdown_requested = true;
+                Ok(())
+            })?
             .on_sync::<lsp_types::request::SelectionRangeRequest>(|s, p| {
                 handlers::handle_selection_range(s.snapshot(), p)
             })?