Changed the app window to open the app via 127.0.0.1

app/MindWork AI Studio/Program.cs

@@ -285,10 +285,15 @@ internal sealed class Program
 
         builder.Services.AddSingleton(new HttpClient
         {
-            BaseAddress = new Uri($"http://localhost:{appPort}")
+            BaseAddress = new Uri($"http://127.0.0.1:{appPort}")
         });
 
-        builder.WebHost.UseUrls($"http://localhost:{appPort}");
+        //
+        // We listen on the IPv4 loopback address only, where the app window goes. With localhost, the
+        // server would listen on the IPv6 loopback address as well, and a client which resolves
+        // localhost could end up with another process holding that port there.
+        //
+        builder.WebHost.UseUrls($"http://127.0.0.1:{appPort}");
 
         #if DEBUG
         builder.WebHost.UseWebRoot("wwwroot");

runtime/src/app_window.rs

@@ -312,7 +312,7 @@ fn is_tauri_asset_url(url: &tauri::Url) -> bool {
     matches!(url.scheme(), "http" | "https") && is_tauri_asset_host(url.host_str())
 }
 
-fn is_local_http_url(url: &tauri::Url) -> bool {
+pub(crate) fn is_local_http_url(url: &tauri::Url) -> bool {
     matches!(url.scheme(), "http" | "https") && is_local_host(url.host_str())
 }
 
@@ -678,7 +678,7 @@ pub fn send_event(event: Event) {
 }
 
 /// Changes the location of the main window to the given URL.
-pub async fn change_location_to(url: &str) {
+pub async fn change_location_to(url: tauri::Url) {
     // Try to get the main window. If it is not available yet, wait for it:
     let mut main_window_ready = false;
     let mut main_window_status_reported = false;
@@ -700,13 +700,18 @@ pub async fn change_location_to(url: &str) {
         }
     }
 
-    if let Ok(parsed_url) = tauri::Url::parse(url) && is_local_http_url(&parsed_url) {
-        *APPROVED_APP_URL.lock().unwrap() = Some(parsed_url);
+    if is_local_http_url(&url) {
+        *APPROVED_APP_URL.lock().unwrap() = Some(url.clone());
     }
 
-    let js_location_change = format!("window.location = '{url}';");
-    let main_window = main_window_spawn_clone.lock().unwrap();
-    let location_change_result = main_window.as_ref().unwrap().eval(js_location_change.as_str());
+    //
+    // The window navigates by itself instead of through a script of the page it shows. That page
+    // comes from Tauri, which is another site than the app, so the app would count as opened by
+    // another site. We take the window out of the lock first: navigating needs the main thread,
+    // which may wait for this lock meanwhile.
+    //
+    let main_window = main_window_spawn_clone.lock().unwrap().clone().unwrap();
+    let location_change_result = main_window.navigate(url.clone());
     match location_change_result {
         Ok(_) => info!("The app location was changed to {url}."),
         Err(e) => error!("Failed to change the app location to {url}: {e}."),

runtime/src/dotnet.rs

@@ -303,7 +303,7 @@ pub async fn dotnet_ready() {
     }
 
     let dotnet_server_port = *DOTNET_SERVER_PORT;
-    let url = match Url::parse(format!("http://localhost:{dotnet_server_port}").as_str())
+    let url = match Url::parse(app_address(dotnet_server_port).as_str())
     {
         Ok(url) => url,
         Err(msg) => {
@@ -312,7 +312,14 @@ pub async fn dotnet_ready() {
         }
     };
 
-    change_location_to(url.as_str()).await;
+    change_location_to(url).await;
+}
+
+/// Returns the address of the app on the .NET server. The server listens on the IPv4 loopback
+/// address only, so the window goes there directly instead of resolving `localhost`, which may
+/// answer with the IPv6 loopback address first.
+fn app_address(port: u16) -> String {
+    format!("http://127.0.0.1:{port}/")
 }
 
 /// Stops the .NET server process.
@@ -337,3 +344,24 @@ pub fn cleanup_dotnet_server() {
         warn!(Source = ".NET"; "Error during the cleanup of .NET: {}", e);
     }
 }
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use crate::app_window::is_local_http_url;
+
+    #[test]
+    fn the_app_address_is_the_ipv4_loopback_address() {
+        let url = Url::parse(app_address(61153).as_str()).unwrap();
+
+        assert_eq!(url.host_str(), Some("127.0.0.1"));
+        assert_eq!(url.port(), Some(61153));
+        assert_eq!(url.path(), "/");
+    }
+
+    #[test]
+    fn the_app_address_counts_as_local() {
+        let url = Url::parse(app_address(61153).as_str()).unwrap();
+        assert!(is_local_http_url(&url));
+    }
+}