Add error applet support + error applet panic hook

ctru-rs/src/applets/error.rs

@@ -88,17 +88,21 @@ impl PopUp {
     }
 }
 
-/// Sets a custom panic hook that uses the error applet to display panic messages. You can also choose to have
-/// messages printed over stderr along with the pop-up display.
+/// Sets a custom panic hook that uses the error applet to display panic messages. You can also choose to have the
+/// default panic hook called to print the message over stderr.
 ///
-/// If the `Gfx` service is not initialized during a panic, the error applet will not be displayed and the panic
-/// message will be printed over stderr.
-pub fn set_panic_hook(use_stderr: bool) {
+/// If the `Gfx` service is not initialized during a panic, the error applet will not be displayed and the default
+/// hook will be called.
+pub fn set_panic_hook(call_default_hook: bool) {
     use crate::services::gfx::GFX_ACTIVE;
-
-    use std::io::Write;
     use std::sync::TryLockError;
 
+    // Ensure we get the default hook instead of a previously registered user hook.
+    let default_hook = {
+        let _ = std::panic::take_hook();
+        std::panic::take_hook()
+    };
+
     std::panic::set_hook(Box::new(move |panic_info| {
         let thread = std::thread::current();
 
@@ -107,8 +111,8 @@ pub fn set_panic_hook(use_stderr: bool) {
         // If we get a `WouldBlock` error, we know that the `Gfx` service has been initialized.
         // Otherwise fallback to printing over stderr.
         if let (Err(TryLockError::WouldBlock), Ok(_apt)) = (GFX_ACTIVE.try_lock(), Apt::new()) {
-            if use_stderr {
-                print_to_stderr(name, panic_info);
+            if call_default_hook {
+                default_hook(panic_info);
             }
 
             let payload = format!("thread '{name}' {panic_info}");
@@ -121,15 +125,9 @@ pub fn set_panic_hook(use_stderr: bool) {
                 popup.launch_unchecked();
             }
         } else {
-            print_to_stderr(name, panic_info);
+            default_hook(panic_info);
         }
     }));
-
-    fn print_to_stderr(name: &str, panic_info: &std::panic::PanicInfo) {
-        let mut stderr = std::io::stderr().lock();
-
-        let _ = writeln!(stderr, "thread '{name}' {panic_info}");
-    }
 }
 
 impl std::fmt::Display for Error {