From 38f800d8779623161db8a57ee5bc115f3073a9ff Mon Sep 17 00:00:00 2001
From: Sebastian Thiel <sebastian.thiel@icloud.com>
Date: Thu, 11 Jul 2024 09:18:39 +0200
Subject: [PATCH] assure the multi-window lock actually works

This includes the UI is responding to issues.
---
 app/src/routes/[projectId]/+layout.ts |  4 +++-
 crates/gitbutler-tauri/src/window.rs  | 19 +++++++++++++++----
 2 files changed, 18 insertions(+), 5 deletions(-)

diff --git a/app/src/routes/[projectId]/+layout.ts b/app/src/routes/[projectId]/+layout.ts
index 6a747fc7d..9d663bbbc 100644
--- a/app/src/routes/[projectId]/+layout.ts
+++ b/app/src/routes/[projectId]/+layout.ts
@@ -30,10 +30,12 @@ export async function load({ params, parent }) {
 	// Getting the project should be one of few, if not the only await expression in
 	// this function. It delays drawing the page, but currently the benefit from having this
 	// synchronously available are much greater than the cost.
+	// However, what's awaited here is required for proper error handling,
+	// and by now this is fast enough to not be an impediment.
 	let project: Project | undefined = undefined;
 	try {
 		project = await projectService.getProject(projectId);
-		invoke('set_project_active', { id: projectId }).then((_r) => {});
+		await invoke('set_project_active', { id: projectId }).then((_r) => {});
 	} catch (err: any) {
 		throw error(400, {
 			message: err.message
diff --git a/crates/gitbutler-tauri/src/window.rs b/crates/gitbutler-tauri/src/window.rs
index 1065ad24b..c67a576c1 100644
--- a/crates/gitbutler-tauri/src/window.rs
+++ b/crates/gitbutler-tauri/src/window.rs
@@ -2,7 +2,7 @@ pub(super) mod state {
     use std::collections::BTreeMap;
     use std::sync::Arc;
 
-    use anyhow::{Context, Result};
+    use anyhow::{bail, Context, Result};
     use futures::executor::block_on;
     use gitbutler_project as projects;
     use gitbutler_project::ProjectId;
@@ -135,18 +135,29 @@ pub(super) mod state {
             window: &WindowLabelRef,
             project: &projects::Project,
         ) -> Result<()> {
+            let mut state_by_label = block_on(self.state.lock());
+            if let Some(state) = state_by_label.get(window) {
+                if state.project_id == project.id {
+                    return Ok(());
+                }
+            }
             let mut lock_file =
                 fslock::LockFile::open(project.gb_dir().join(WINDOW_LOCK_FILE).as_os_str())?;
-            lock_file
+            let got_lock = lock_file
                 .try_lock()
-                .context("Another GitButler Window already has the project opened")?;
+                .context("Failed to check if lock is taken")?;
+            if !got_lock {
+                bail!(
+                    "Project '{}' is already opened in another window",
+                    project.title
+                );
+            }
 
             let handler = handler_from_app(&self.app_handle)?;
             let worktree_dir = project.path.clone();
             let project_id = project.id;
             let watcher =
                 gitbutler_watcher::watch_in_background(handler, worktree_dir, project_id)?;
-            let mut state_by_label = block_on(self.state.lock());
             state_by_label.insert(
                 window.to_owned(),
                 State {