Windows relaunches after an update (#1748)

After the MSI installer finishes, wait for msiexec and start the installed exe; relaunch is detached on Windows.

apps/solidcraft/src/main.rs

@@ -94,10 +94,20 @@ impl eframe::App for App {
         solidcraft_ui_egui::recovery_ui::close(&mut self.solve);
         solidcraft_engine::crash::end_session();
         // An update asked to restart into the new version or to run its installer.
-        if let Some((program, args)) = solidcraft_ui_egui::update::take_launch(&mut self.solve)
-            && let Err(e) = std::process::Command::new(&program).args(&args).spawn()
-        {
-            log::error!("update: starting {}: {e}", program.display());
+        if let Some((program, args)) = solidcraft_ui_egui::update::take_launch(&mut self.solve) {
+            let mut command = std::process::Command::new(&program);
+            command.args(&args);
+            #[cfg(windows)]
+            {
+                use std::os::windows::process::CommandExt;
+                // Not tied to this process: its own process group, and no console (the PowerShell
+                // that waits for an installer is hidden; the app itself is detached).
+                let hidden_shell = program.file_stem().is_some_and(|n| n.eq_ignore_ascii_case("powershell"));
+                command.creation_flags(0x0000_0200 | if hidden_shell { 0x0800_0000 } else { 0x0000_0008 });
+            }
+            if let Err(e) = command.spawn() {
+                log::error!("update: starting {}: {e}", program.display());
+            }
         }
     }
 }

crates/ui-egui/src/update.rs

@@ -697,8 +697,13 @@ fn poll_install(app: &mut SolveApp) {
     app.updater.job = None;
     match &result {
         Ok(install::Outcome::Installer(program, args)) => {
-            // The installer replaces this program: start it once SolidCraft has closed.
-            app.updater.launch = Some((program.clone(), args.clone()));
+            // The installer replaces this program: start it once SolidCraft has closed. On
+            // Windows the installer is followed by the new version (see install::relaunch_after).
+            app.updater.launch = Some(match std::env::current_exe() {
+                #[cfg(windows)]
+                Ok(exe) => install::relaunch_after(program, args, &exe),
+                _ => (program.clone(), args.clone()),
+            });
             crate::documents::request_quit(app);
         }
         Ok(install::Outcome::Opened(dmg)) => {

crates/ui-egui/src/update/install.rs

@@ -107,6 +107,26 @@ pub fn sha256_file(path: &Path) -> Result<String, String> {
     Ok(h.finalize().iter().map(|b| format!("{b:02x}")).collect())
 }
 
+/// The command that runs an installer, waits for it to finish and then starts `exe` (the
+/// installed program), so the app comes back after an update. Windows has no `wait && start` in
+/// a plain process spawn, so PowerShell does the waiting; the installer's exit code is ignored on
+/// purpose: when the user cancels it, the old version is still there to start.
+pub fn relaunch_after(installer: &Path, args: &[String], exe: &Path) -> (PathBuf, Vec<String>) {
+    // PowerShell single-quoted string: only `'` needs doubling.
+    let q = |s: &str| format!("'{}'", s.replace('\'', "''"));
+    // msiexec splits its command line itself, so an argument with spaces needs its own quotes.
+    let list = args.iter().map(|a| if a.contains(' ') { q(&format!("\"{a}\"")) } else { q(a) }).collect::<Vec<_>>().join(",");
+    let script = format!(
+        "Start-Process -FilePath {} -ArgumentList {list} -Wait; Start-Process -FilePath {}",
+        q(&installer.to_string_lossy()),
+        q(&exe.to_string_lossy())
+    );
+    (
+        PathBuf::from("powershell"),
+        vec!["-NoProfile".into(), "-NonInteractive".into(), "-WindowStyle".into(), "Hidden".into(), "-Command".into(), script],
+    )
+}
+
 /// `sums` is signed by `key` (minisign, prehashed) with a trusted comment naming `tag`.
 pub fn verify_signature(sums: &[u8], signature: &str, key: &str, tag: &str) -> Result<(), String> {
     let key = minisign_verify::PublicKey::from_base64(key.trim()).map_err(|e| format!("update signing key: {e}"))?;

crates/ui-egui/src/update/install_tests.rs

@@ -203,3 +203,18 @@ fn installers_and_disk_images_are_handed_over() {
     assert_eq!(apply(&Method::Dmg, &pkg).unwrap(), Outcome::Opened(pkg.clone()));
     let _ = std::fs::remove_dir_all(&dir);
 }
+
+#[test]
+fn windows_installer_is_followed_by_the_new_version() {
+    let args = vec!["/i".to_string(), r"C:\Users\a b\Temp\solidcraft-update\x.msi".to_string(), "/passive".to_string()];
+    let (program, out) = relaunch_after(Path::new("msiexec"), &args, Path::new(r"C:\Program Files\SolidCraft\it's.exe"));
+    assert_eq!(program, PathBuf::from("powershell"));
+    assert_eq!(
+        out.last().unwrap(),
+        &concat!(
+            r#"Start-Process -FilePath 'msiexec' -ArgumentList '/i','"C:\Users\a b\Temp\solidcraft-update\x.msi"','/passive' -Wait; "#,
+            r"Start-Process -FilePath 'C:\Program Files\SolidCraft\it''s.exe'"
+        )
+    );
+    assert!(out.iter().any(|a| a == "-Command"));
+}