Harden window evidence adapters

src/window/linux.rs

@@ -27,8 +27,12 @@ pub fn get_snapshot() -> WindowSnapshot {
 
 pub fn minimize_other(title: &str) {
     let window_info = get_window_info();
-    if &window_info.title != title {
-        run(&format!("xdotool windowminimize {}", window_info.wid));
+    if window_info.wid.is_empty() {
+        return;
+    }
+
+    if window_info.title != title {
+        run_xdotool(&["windowminimize", &window_info.wid]);
     }
 }
 
@@ -38,8 +42,12 @@ struct WindowInfo {
     wid: String,
 }
 
-fn run(cmd: &str) -> Option<String> {
-    let output = Command::new("sh").arg("-c").arg(cmd).output();
+fn is_valid_window_id(wid: &str) -> bool {
+    !wid.is_empty() && wid.bytes().all(|byte| byte.is_ascii_digit())
+}
+
+fn run_xdotool(args: &[&str]) -> Option<String> {
+    let output = Command::new("xdotool").args(args).output();
 
     let Ok(Output {
         status,
@@ -68,17 +76,38 @@ fn get_window_info() -> WindowInfo {
         wid: "".to_string(),
     };
 
-    let Some(wid) = run("xdotool getactivewindow") else {
+    let Some(wid) = run_xdotool(&["getactivewindow"]) else {
         return none;
     };
 
-    let Some(class) = run(&format!("xdotool getwindowclassname {wid}")) else {
+    if !is_valid_window_id(&wid) {
         return none;
     };
 
-    let Some(title) = run(&format!("xdotool getwindowname {wid}")) else {
+    let Some(class) = run_xdotool(&["getwindowclassname", &wid]) else {
+        return none;
+    };
+
+    let Some(title) = run_xdotool(&["getwindowname", &wid]) else {
         return none;
     };
 
     WindowInfo { title, class, wid }
 }
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn valid_window_id_accepts_ascii_digits_only() {
+        assert!(is_valid_window_id("12345"));
+        assert!(is_valid_window_id("0"));
+
+        assert!(!is_valid_window_id(""));
+        assert!(!is_valid_window_id("12abc"));
+        assert!(!is_valid_window_id(" 123"));
+        assert!(!is_valid_window_id("123 "));
+        assert!(!is_valid_window_id("１２３"));
+    }
+}

src/window/windows.rs

@@ -10,19 +10,32 @@ pub fn get_title_clean() -> String {
 }
 
 pub fn get_snapshot() -> WindowSnapshot {
-    let title = get_window_info().title;
+    let window_info = get_window_info();
+    if window_info.hwnd.is_null() {
+        return WindowSnapshot::unavailable("foreground window unavailable");
+    }
+
     let re = Regex::new(r"-?\d+([:.]\d+)+%?").unwrap();
+    let title = re.replace_all(&window_info.title, "").to_string();
+    let health = if window_info.title.is_empty() {
+        EvidenceHealth::Degraded("foreground window title unavailable".to_string())
+    } else {
+        EvidenceHealth::Degraded("window class unavailable on current Windows adapter".to_string())
+    };
+
     WindowSnapshot {
-        title: re.replace_all(&title, "").to_string(),
+        title,
         class: None,
-        health: EvidenceHealth::Degraded(
-            "window class unavailable on current Windows adapter".to_string(),
-        ),
+        health,
     }
 }
 
 pub fn minimize_other(title: &str) {
     let window_info = get_window_info();
+    if window_info.hwnd.is_null() {
+        return;
+    }
+
     if window_info.title != title {
         unsafe {
             ShowWindow(window_info.hwnd, SW_MINIMIZE);
@@ -38,6 +51,13 @@ struct WindowInfo {
 fn get_window_info() -> WindowInfo {
     unsafe {
         let hwnd = GetForegroundWindow();
+        if hwnd.is_null() {
+            return WindowInfo {
+                title: String::new(),
+                hwnd,
+            };
+        }
+
         let mut text: [u16; 512] = [0; 512];
         let len = GetWindowTextW(hwnd, text.as_mut_ptr(), text.len() as i32) as usize;
         let title = OsString::from_wide(&text[..len])