linux: Store binary path before restart to handle deleted binary file (#11568)

This fixes restart after updates not working on Linux.

On Linux we can't reliably get the binary path after an update, because
the original binary was deleted and the path will contain ` (deleted)`.

See: https://github.com/rust-lang/rust/issues/69343

We *could* strip ` (deleted)` off, but that feels nasty. So instead we
save the original binary path, before we do the installation, then
restart.

Later on, we can also change this to be a _new_ binary path returned by
the installers, which we then have to start.


Release Notes:

- N/A

crates/auto_update/src/auto_update.rs

@@ -56,16 +56,22 @@ struct UpdateRequestBody {
     telemetry: bool,
 }
 
-#[derive(Clone, Copy, PartialEq, Eq)]
+#[derive(Clone, PartialEq, Eq)]
 pub enum AutoUpdateStatus {
     Idle,
     Checking,
     Downloading,
     Installing,
-    Updated,
+    Updated { binary_path: PathBuf },
     Errored,
 }
 
+impl AutoUpdateStatus {
+    pub fn is_updated(&self) -> bool {
+        matches!(self, Self::Updated { .. })
+    }
+}
+
 pub struct AutoUpdater {
     status: AutoUpdateStatus,
     current_version: SemanticVersion,
@@ -306,7 +312,7 @@ impl AutoUpdater {
     }
 
     pub fn poll(&mut self, cx: &mut ModelContext<Self>) {
-        if self.pending_poll.is_some() || self.status == AutoUpdateStatus::Updated {
+        if self.pending_poll.is_some() || self.status.is_updated() {
             return;
         }
 
@@ -328,7 +334,7 @@ impl AutoUpdater {
     }
 
     pub fn status(&self) -> AutoUpdateStatus {
-        self.status
+        self.status.clone()
     }
 
     pub fn dismiss_error(&mut self, cx: &mut ModelContext<Self>) {
@@ -404,6 +410,11 @@ impl AutoUpdater {
             cx.notify();
         })?;
 
+        // We store the path of our current binary, before we install, since installation might
+        // delete it. Once deleted, it's hard to get the path to our binary on Linux.
+        // So we cache it here, which allows us to then restart later on.
+        let binary_path = cx.update(|cx| cx.app_path())??;
+
         match OS {
             "macos" => install_release_macos(&temp_dir, downloaded_asset, &cx).await,
             "linux" => install_release_linux(&temp_dir, downloaded_asset, &cx).await,
@@ -413,7 +424,7 @@ impl AutoUpdater {
         this.update(&mut cx, |this, cx| {
             this.set_should_show_update_notification(true, cx)
                 .detach_and_log_err(cx);
-            this.status = AutoUpdateStatus::Updated;
+            this.status = AutoUpdateStatus::Updated { binary_path };
             cx.notify();
         })?;