Auto merge of rust-lang#13476 - Veykril:prefer-shutdown, r=Veykril

fix: Don't respond with an error when requesting a shutdown while starting

crates/rust-analyzer/src/main_loop.rs

@@ -607,30 +607,34 @@ impl GlobalState {
 
     /// Handles a request.
     fn on_request(&mut self, req: Request) {
-        if self.shutdown_requested {
-            self.respond(lsp_server::Response::new_err(
-                req.id,
-                lsp_server::ErrorCode::InvalidRequest as i32,
-                "Shutdown already requested.".to_owned(),
-            ));
-            return;
-        }
+        let mut dispatcher = RequestDispatcher { req: Some(req), global_state: self };
+        dispatcher.on_sync_mut::<lsp_types::request::Shutdown>(|s, ()| {
+            s.shutdown_requested = true;
+            Ok(())
+        });
+
+        if let RequestDispatcher { req: Some(req), global_state: this } = &mut dispatcher {
+            if this.shutdown_requested {
+                this.respond(lsp_server::Response::new_err(
+                    req.id.clone(),
+                    lsp_server::ErrorCode::InvalidRequest as i32,
+                    "Shutdown already requested.".to_owned(),
+                ));
+                return;
+            }
 
-        // Avoid flashing a bunch of unresolved references during initial load.
-        if self.workspaces.is_empty() && !self.is_quiescent() {
-            self.respond(lsp_server::Response::new_err(
-                req.id,
-                lsp_server::ErrorCode::ContentModified as i32,
-                "waiting for cargo metadata or cargo check".to_owned(),
-            ));
-            return;
+            // Avoid flashing a bunch of unresolved references during initial load.
+            if this.workspaces.is_empty() && !this.is_quiescent() {
+                this.respond(lsp_server::Response::new_err(
+                    req.id.clone(),
+                    lsp_server::ErrorCode::ContentModified as i32,
+                    "waiting for cargo metadata or cargo check".to_owned(),
+                ));
+                return;
+            }
         }
 
-        RequestDispatcher { req: Some(req), global_state: self }
-            .on_sync_mut::<lsp_types::request::Shutdown>(|s, ()| {
-                s.shutdown_requested = true;
-                Ok(())
-            })
+        dispatcher
             .on_sync_mut::<lsp_ext::ReloadWorkspace>(handlers::handle_workspace_reload)
             .on_sync_mut::<lsp_ext::MemoryUsage>(handlers::handle_memory_usage)
             .on_sync_mut::<lsp_ext::ShuffleCrateGraph>(handlers::handle_shuffle_crate_graph)