fix(single-instance): forward non-Unicode arguments and cwd (#3644)

* Update windows.rs

* Create single-instance-non-unicode-args.md

* fix on linux and windows too

---------

Co-authored-by: Lucas Nogueira <lucas@tauri.app>

plugins/single-instance/src/lib.rs

@@ -39,8 +39,9 @@ pub(crate) type SingleInstanceCallback<R> =
 /// [`Builder::build`]. Use [`Builder`] directly if you need to set a custom [`Builder::dbus_id`].
 ///
 /// `f` is called with the app handle, the second instance's command line arguments
-/// (as collected by [`std::env::args`], so the first element is the executable path) and its
-/// current working directory. If the `deep-link` feature is enabled, the arguments are first
+/// (as collected by [`std::env::args_os`], so the first element is the executable path) and its
+/// current working directory. Arguments and the working directory that are not valid Unicode
+/// have their invalid parts replaced by U+FFFD. If the `deep-link` feature is enabled, the arguments are first
 /// forwarded to [`tauri-plugin-deep-link`](https://crates.io/crates/tauri-plugin-deep-link)
 /// before `f` runs.
 ///

plugins/single-instance/src/platform_impl/linux.rs

@@ -74,11 +74,13 @@ pub fn init<R: Runtime>(
                             Some("org.SingleInstance.DBus"),
                             "ExecuteCallback",
                             &(
-                                std::env::args().collect::<Vec<String>>(),
+                                std::env::args_os()
+                                    .map(|arg| arg.to_string_lossy().into_owned())
+                                    .collect::<Vec<String>>(),
                                 std::env::current_dir()
                                     .unwrap_or_default()
-                                    .to_str()
-                                    .unwrap_or_default(),
+                                    .to_string_lossy()
+                                    .as_ref(),
                             ),
                         );
                     }

plugins/single-instance/src/platform_impl/macos.rs

@@ -80,12 +80,14 @@ fn notify_singleton(socket: &PathBuf) -> Result<(), Error> {
     let mut bf = BufWriter::new(&stream);
     let cwd = std::env::current_dir()
         .unwrap_or_default()
-        .to_str()
-        .unwrap_or_default()
-        .to_string();
+        .to_string_lossy()
+        .into_owned();
     bf.write_all(cwd.as_bytes())?;
     bf.write_all(b"\0\0")?;
-    let args_joined = std::env::args().collect::<Vec<String>>().join("\0");
+    let args_joined = std::env::args_os()
+        .map(|arg| arg.to_string_lossy().into_owned())
+        .collect::<Vec<String>>()
+        .join("\0");
     bf.write_all(args_joined.as_bytes())?;
     bf.flush()?;
     drop(bf);

plugins/single-instance/src/platform_impl/windows.rs

@@ -86,9 +86,12 @@ pub fn init<R: Runtime>(callback: Box<SingleInstanceCallback<R>>) -> TauriPlugin
                         }
 
                         let cwd = std::env::current_dir().unwrap_or_default();
-                        let cwd = cwd.to_str().unwrap_or_default();
+                        let cwd = cwd.to_string_lossy();
 
-                        let args = std::env::args().collect::<Vec<String>>().join("|");
+                        let args = std::env::args_os()
+                            .map(|arg| arg.to_string_lossy().into_owned())
+                            .collect::<Vec<String>>()
+                            .join("|");
 
                         let data = format!("{cwd}|{args}\0",);