From dc2959396c191696ee3d79f9793799d20e9fc1c1 Mon Sep 17 00:00:00 2001
From: Fenrir <fenrirwolf@gmail.com>
Date: Mon, 19 Feb 2024 14:41:01 -0700
Subject: [PATCH 01/17] Add basic error applet support

---
 ctru-rs/src/applets/error.rs | 56 ++++++++++++++++++++++++++++++++++++
 ctru-rs/src/applets/mod.rs   |  1 +
 ctru-sys/build.rs            |  2 ++
 ctru-sys/src/lib.rs          | 16 +++++++++++
 4 files changed, 75 insertions(+)
 create mode 100644 ctru-rs/src/applets/error.rs

diff --git a/ctru-rs/src/applets/error.rs b/ctru-rs/src/applets/error.rs
new file mode 100644
index 00000000..ef7cea7f
--- /dev/null
+++ b/ctru-rs/src/applets/error.rs
@@ -0,0 +1,56 @@
+//! Error applet
+//!
+//! This applet displays error text as a pop-up message on the lower screen.
+#![doc(alias = "Error")]
+
+use crate::services::{apt::Apt, gfx::Gfx};
+
+use ctru_sys::errorConf;
+
+/// Configuration struct to set up the Error applet.
+#[doc(alias = "errorConf")]
+pub struct ErrorApplet {
+    state: Box<errorConf>,
+}
+
+/// The kind of error applet to display.
+#[doc(alias = "errorType")]
+#[derive(Copy, Clone, Debug, PartialEq, Eq)]
+#[repr(u32)]
+pub enum Kind {
+    /// Error text is centered in the error applet window.
+    Center = ctru_sys::ERROR_TEXT,
+    /// Error text starts at the top of the error applet window.
+    Top = ctru_sys::ERROR_TEXT_WORD_WRAP,
+}
+
+impl ErrorApplet {
+    /// Initialize the error applet with the provided text kind.
+    #[doc(alias = "errorInit")]
+    pub fn new(kind: Kind) -> Self {
+        let mut state = Box::<errorConf>::default();
+
+        unsafe { ctru_sys::errorInit(state.as_mut(), kind as _, 0) };
+
+        Self { state }
+    }
+
+    /// Sets the error text to display.
+    #[doc(alias = "errorText")]
+    pub fn set_text(&mut self, text: &str) {
+        for (idx, code_unit) in text
+            .encode_utf16()
+            .chain(std::iter::once(0))
+            .take(self.state.Text.len() - 1)
+            .enumerate()
+        {
+            self.state.Text[idx] = code_unit;
+        }
+    }
+
+    /// Launches the error applet.
+    #[doc(alias = "errorDisp")]
+    pub fn launch(&mut self, _apt: &Apt, _gfx: &Gfx) {
+        unsafe { ctru_sys::errorDisp(self.state.as_mut()) }
+    }
+}
diff --git a/ctru-rs/src/applets/mod.rs b/ctru-rs/src/applets/mod.rs
index 244fb74f..838ef6b7 100644
--- a/ctru-rs/src/applets/mod.rs
+++ b/ctru-rs/src/applets/mod.rs
@@ -8,5 +8,6 @@
 //!
 //! Applets block execution of the thread that launches them as long as the user doesn't close the applet.
 
+pub mod error;
 pub mod mii_selector;
 pub mod swkbd;
diff --git a/ctru-sys/build.rs b/ctru-sys/build.rs
index 5e71ae05..ff140bb3 100644
--- a/ctru-sys/build.rs
+++ b/ctru-sys/build.rs
@@ -79,6 +79,8 @@ fn main() {
         .blocklist_type("u(8|16|32|64)")
         .blocklist_type("__builtin_va_list")
         .blocklist_type("__va_list")
+        .blocklist_type("errorReturnCode")
+        .blocklist_type("errorScreenFlag")
         .opaque_type("MiiData")
         .derive_default(true)
         .wrap_static_fns(true)
diff --git a/ctru-sys/src/lib.rs b/ctru-sys/src/lib.rs
index b9f71de9..38f0d37a 100644
--- a/ctru-sys/src/lib.rs
+++ b/ctru-sys/src/lib.rs
@@ -16,6 +16,22 @@
 pub mod result;
 pub use result::*;
 
+// Fun fact: bindgen can and will generate enum values of the wrong size, and if a generated struct contains fields
+// using those values, then that struct will have the wrong size and field offsets too. To fix that problem,
+// you have to blocklist the enum type in bindgen and manually define it with the proper data type.
+pub const ERROR_UNKNOWN: errorReturnCode = -1;
+pub const ERROR_NONE: errorReturnCode = 0;
+pub const ERROR_SUCCESS: errorReturnCode = 1;
+pub const ERROR_NOT_SUPPORTED: errorReturnCode = 2;
+pub const ERROR_HOME_BUTTON: errorReturnCode = 10;
+pub const ERROR_SOFTWARE_RESET: errorReturnCode = 11;
+pub const ERROR_POWER_BUTTON: errorReturnCode = 12;
+pub type errorReturnCode = libc::c_schar;
+
+pub const ERROR_NORMAL: errorScreenFlag = 0;
+pub const ERROR_STEREO: errorScreenFlag = 1;
+pub type errorScreenFlag = libc::c_char;
+
 include!(concat!(env!("OUT_DIR"), "/bindings.rs"));
 
 /// In lieu of a proper errno function exposed by libc

From a75ac1ffd23e42870938f1e6dbc8475e83ab79f2 Mon Sep 17 00:00:00 2001
From: Fenrir <fenrirwolf@gmail.com>
Date: Mon, 19 Feb 2024 21:08:27 -0700
Subject: [PATCH 02/17] Clarify comment on manually implemented enum types

---
 ctru-sys/src/lib.rs | 8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

diff --git a/ctru-sys/src/lib.rs b/ctru-sys/src/lib.rs
index 38f0d37a..39484a36 100644
--- a/ctru-sys/src/lib.rs
+++ b/ctru-sys/src/lib.rs
@@ -16,9 +16,11 @@
 pub mod result;
 pub use result::*;
 
-// Fun fact: bindgen can and will generate enum values of the wrong size, and if a generated struct contains fields
-// using those values, then that struct will have the wrong size and field offsets too. To fix that problem,
-// you have to blocklist the enum type in bindgen and manually define it with the proper data type.
+// Fun fact: C compilers are allowed to represent enums as the smallest integer type that can hold all of its variants,
+// meaning that enums are allowed to be the size of a `c_short` or a `c_char` rather than the size of a `c_int`.
+// Libctru's `errorConf` struct contains two enums that depend on this narrowing property for size and alignment purposes,
+// and since `bindgen` generates all enums with `c_int` sizing, we have to blocklist those types and manually define them
+// here with the proper size.
 pub const ERROR_UNKNOWN: errorReturnCode = -1;
 pub const ERROR_NONE: errorReturnCode = 0;
 pub const ERROR_SUCCESS: errorReturnCode = 1;

From cd309813483d4fffdc2061487b37f9e3f50b0163 Mon Sep 17 00:00:00 2001
From: Fenrir <fenrirwolf@gmail.com>
Date: Fri, 23 Feb 2024 15:41:52 -0700
Subject: [PATCH 03/17] Rename error applet config struct

---
 ctru-rs/src/applets/error.rs | 4 +---
 1 file changed, 1 insertion(+), 3 deletions(-)

diff --git a/ctru-rs/src/applets/error.rs b/ctru-rs/src/applets/error.rs
index ef7cea7f..b5af8717 100644
--- a/ctru-rs/src/applets/error.rs
+++ b/ctru-rs/src/applets/error.rs
@@ -1,15 +1,13 @@
 //! Error applet
 //!
 //! This applet displays error text as a pop-up message on the lower screen.
-#![doc(alias = "Error")]
-
 use crate::services::{apt::Apt, gfx::Gfx};
 
 use ctru_sys::errorConf;
 
 /// Configuration struct to set up the Error applet.
 #[doc(alias = "errorConf")]
-pub struct ErrorApplet {
+pub struct PopUp {
     state: Box<errorConf>,
 }
 

From a9ded199fa93ed37cb3cd59f491338a756a41120 Mon Sep 17 00:00:00 2001
From: Fenrir <fenrirwolf@gmail.com>
Date: Fri, 23 Feb 2024 16:09:41 -0700
Subject: [PATCH 04/17] Handle error codes returned by the Error applet

---
 ctru-rs/src/applets/error.rs | 44 ++++++++++++++++++++++++++++++++++--
 1 file changed, 42 insertions(+), 2 deletions(-)

diff --git a/ctru-rs/src/applets/error.rs b/ctru-rs/src/applets/error.rs
index b5af8717..c60c4a8b 100644
--- a/ctru-rs/src/applets/error.rs
+++ b/ctru-rs/src/applets/error.rs
@@ -22,7 +22,24 @@ pub enum Kind {
     Top = ctru_sys::ERROR_TEXT_WORD_WRAP,
 }
 
-impl ErrorApplet {
+/// Error returned by an unsuccessful [`PopUp::launch()`].
+#[doc(alias = "errorReturnCode")]
+#[derive(Copy, Clone, Debug, PartialEq, Eq)]
+#[repr(i8)]
+pub enum Error {
+    /// Unknown error occurred.
+    Unknown = ctru_sys::ERROR_UNKNOWN,
+    /// Operation not supported.
+    NotSupported = ctru_sys::ERROR_NOT_SUPPORTED,
+    /// Home button pressed while [`PopUp`] was running.
+    HomePressed = ctru_sys::ERROR_HOME_BUTTON,
+    /// Power button pressed while [`PopUp`] was running.
+    PowerPressed = ctru_sys::ERROR_POWER_BUTTON,
+    /// Reset button pressed while [`PopUp`] was running.
+    ResetPressed = ctru_sys::ERROR_SOFTWARE_RESET,
+}
+
+impl PopUp {
     /// Initialize the error applet with the provided text kind.
     #[doc(alias = "errorInit")]
     pub fn new(kind: Kind) -> Self {
@@ -48,7 +65,30 @@ impl ErrorApplet {
 
     /// Launches the error applet.
     #[doc(alias = "errorDisp")]
-    pub fn launch(&mut self, _apt: &Apt, _gfx: &Gfx) {
+    pub fn launch(&mut self, _apt: &Apt, _gfx: &Gfx) -> Result<(), Error> {
         unsafe { ctru_sys::errorDisp(self.state.as_mut()) }
+
+        match self.state.returnCode {
+            ctru_sys::ERROR_NONE | ctru_sys::ERROR_SUCCESS => Ok(()),
+            ctru_sys::ERROR_NOT_SUPPORTED => Err(Error::NotSupported),
+            ctru_sys::ERROR_HOME_BUTTON => Err(Error::HomePressed),
+            ctru_sys::ERROR_POWER_BUTTON => Err(Error::PowerPressed),
+            ctru_sys::ERROR_SOFTWARE_RESET => Err(Error::ResetPressed),
+            _ => Err(Error::Unknown),
+        }
     }
 }
+
+impl std::fmt::Display for Error {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        match self {
+            Self::NotSupported => write!(f, "operation not supported"),
+            Self::HomePressed => write!(f, "home button pressed while error applet was running"),
+            Self::PowerPressed => write!(f, "power button pressed while error applet was running"),
+            Self::ResetPressed => write!(f, "reset button pressed while error applet was running"),
+            Self::Unknown => write!(f, "an unknown error occurred"),
+        }
+    }
+}
+
+impl std::error::Error for Error {}

From c6d5cdc3679ba4806be5b2cef80cdd417ee177cb Mon Sep 17 00:00:00 2001
From: Fenrir <fenrirwolf@gmail.com>
Date: Fri, 23 Feb 2024 18:25:43 -0700
Subject: [PATCH 05/17] Add error applet panic hook

---
 ctru-rs/src/applets/error.rs | 28 ++++++++++++++++++++++++++++
 1 file changed, 28 insertions(+)

diff --git a/ctru-rs/src/applets/error.rs b/ctru-rs/src/applets/error.rs
index c60c4a8b..584a2b48 100644
--- a/ctru-rs/src/applets/error.rs
+++ b/ctru-rs/src/applets/error.rs
@@ -79,6 +79,34 @@ 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.
+///
+/// SAFETY: The error applet requires that both the [`Apt`] and [`Gfx`] services are active whenever it launches.
+/// By calling this function, you promise that you will keep those services alive until either the program ends or
+/// you unregister this hook with [`std::panic::take_hook`](https://doc.rust-lang.org/std/panic/fn.take_hook.html).
+pub unsafe fn set_panic_hook(use_stderr: bool) {
+    std::panic::set_hook(Box::new(move |panic_info| {
+        let mut popup = PopUp::new(Kind::Top);
+
+        let thread = std::thread::current();
+
+        let name = thread.name().unwrap_or("<unnamed>");
+
+        let payload = format!("thread '{name}' {panic_info}");
+
+        popup.set_text(&payload);
+
+        if use_stderr {
+            eprintln!("{payload}");
+        }
+
+        unsafe {
+            ctru_sys::errorDisp(popup.state.as_mut());
+        }
+    }))
+}
+
 impl std::fmt::Display for Error {
     fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         match self {

From d32cd1525f2a2a5d34febdf91f6586e7f872cbce Mon Sep 17 00:00:00 2001
From: Fenrir <fenrirwolf@gmail.com>
Date: Fri, 23 Feb 2024 18:48:35 -0700
Subject: [PATCH 06/17] Properly document safety concerns

---
 ctru-rs/src/applets/error.rs | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/ctru-rs/src/applets/error.rs b/ctru-rs/src/applets/error.rs
index 584a2b48..06e5ffec 100644
--- a/ctru-rs/src/applets/error.rs
+++ b/ctru-rs/src/applets/error.rs
@@ -82,7 +82,9 @@ 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.
 ///
-/// SAFETY: The error applet requires that both the [`Apt`] and [`Gfx`] services are active whenever it launches.
+/// # Safety
+///
+/// The error applet requires that both the [`Apt`] and [`Gfx`] services are active whenever it launches.
 /// By calling this function, you promise that you will keep those services alive until either the program ends or
 /// you unregister this hook with [`std::panic::take_hook`](https://doc.rust-lang.org/std/panic/fn.take_hook.html).
 pub unsafe fn set_panic_hook(use_stderr: bool) {

From 17dc4c4c76e2581e4fa6da21daaba82e8a47245a Mon Sep 17 00:00:00 2001
From: Fenrir <fenrirwolf@gmail.com>
Date: Fri, 23 Feb 2024 19:06:59 -0700
Subject: [PATCH 07/17] Add private PopUp::launch_unchecked method

---
 ctru-rs/src/applets/error.rs | 11 ++++++++++-
 1 file changed, 10 insertions(+), 1 deletion(-)

diff --git a/ctru-rs/src/applets/error.rs b/ctru-rs/src/applets/error.rs
index 06e5ffec..ac9a3db4 100644
--- a/ctru-rs/src/applets/error.rs
+++ b/ctru-rs/src/applets/error.rs
@@ -77,6 +77,15 @@ impl PopUp {
             _ => Err(Error::Unknown),
         }
     }
+
+    /// Launches the error applet without requiring an [`Apt`] or [`Gfx`] handle.
+    ///
+    /// # Safety
+    ///
+    /// Causes undefined behavior if the aforementioned services are not actually active when the applet launches.
+    unsafe fn launch_unchecked(&mut self) {
+        unsafe { ctru_sys::errorDisp(self.state.as_mut()) };
+    }
 }
 
 /// Sets a custom panic hook that uses the error applet to display panic messages. You can also choose to have
@@ -104,7 +113,7 @@ pub unsafe fn set_panic_hook(use_stderr: bool) {
         }
 
         unsafe {
-            ctru_sys::errorDisp(popup.state.as_mut());
+            popup.launch_unchecked();
         }
     }))
 }

From a67c8c0bf64378968c6420dcb18cb8d09b67f862 Mon Sep 17 00:00:00 2001
From: Fenrir <fenrirwolf@gmail.com>
Date: Sun, 25 Feb 2024 01:46:50 -0700
Subject: [PATCH 08/17] Make `set_panic_hook` into a safe fn

---
 ctru-rs/src/applets/error.rs | 49 +++++++++++++++++++++++++-----------
 ctru-rs/src/services/gfx.rs  |  2 +-
 2 files changed, 35 insertions(+), 16 deletions(-)

diff --git a/ctru-rs/src/applets/error.rs b/ctru-rs/src/applets/error.rs
index ac9a3db4..6fa7efcf 100644
--- a/ctru-rs/src/applets/error.rs
+++ b/ctru-rs/src/applets/error.rs
@@ -91,31 +91,50 @@ 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.
 ///
-/// # Safety
-///
-/// The error applet requires that both the [`Apt`] and [`Gfx`] services are active whenever it launches.
-/// By calling this function, you promise that you will keep those services alive until either the program ends or
-/// you unregister this hook with [`std::panic::take_hook`](https://doc.rust-lang.org/std/panic/fn.take_hook.html).
-pub unsafe 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 panic
+/// message will be printed over stderr.
+pub fn set_panic_hook(use_stderr: bool) {
+    use crate::services::gfx::GFX_ACTIVE;
+
+    use std::io::Write;
+    use std::sync::TryLockError;
+
     std::panic::set_hook(Box::new(move |panic_info| {
-        let mut popup = PopUp::new(Kind::Top);
+        let _apt = Apt::new();
 
         let thread = std::thread::current();
 
         let name = thread.name().unwrap_or("<unnamed>");
 
-        let payload = format!("thread '{name}' {panic_info}");
+        // If we get a `WouldBlock` error, we know that the `Gfx` service has been initialized.
+        // Otherwise fallback to printing over stderr.
+        match GFX_ACTIVE.try_lock() {
+            Err(TryLockError::WouldBlock) => {
+                if use_stderr {
+                    print_to_stderr(name, panic_info);
+                }
 
-        popup.set_text(&payload);
+                let payload = format!("thread '{name}' {panic_info}");
 
-        if use_stderr {
-            eprintln!("{payload}");
-        }
+                let mut popup = PopUp::new(Kind::Top);
 
-        unsafe {
-            popup.launch_unchecked();
+                popup.set_text(&payload);
+
+                unsafe {
+                    popup.launch_unchecked();
+                }
+            }
+            _ => {
+                print_to_stderr(name, 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 {
diff --git a/ctru-rs/src/services/gfx.rs b/ctru-rs/src/services/gfx.rs
index 7a6ec6e4..97996658 100644
--- a/ctru-rs/src/services/gfx.rs
+++ b/ctru-rs/src/services/gfx.rs
@@ -239,7 +239,7 @@ pub struct Gfx {
     _service_handler: ServiceReference,
 }
 
-static GFX_ACTIVE: Mutex<()> = Mutex::new(());
+pub(crate) static GFX_ACTIVE: Mutex<()> = Mutex::new(());
 
 impl Gfx {
     /// Initialize a new default service handle.

From a65b9ed57738ae50c4df67fbd657713fa24d1201 Mon Sep 17 00:00:00 2001
From: Fenrir <fenrirwolf@gmail.com>
Date: Sun, 25 Feb 2024 02:06:24 -0700
Subject: [PATCH 09/17] use `if let` in panic hook instead of `match`

---
 ctru-rs/src/applets/error.rs | 25 +++++++++++--------------
 1 file changed, 11 insertions(+), 14 deletions(-)

diff --git a/ctru-rs/src/applets/error.rs b/ctru-rs/src/applets/error.rs
index 6fa7efcf..b723aa8b 100644
--- a/ctru-rs/src/applets/error.rs
+++ b/ctru-rs/src/applets/error.rs
@@ -108,25 +108,22 @@ 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.
-        match GFX_ACTIVE.try_lock() {
-            Err(TryLockError::WouldBlock) => {
-                if use_stderr {
-                    print_to_stderr(name, panic_info);
-                }
+        if let Err(TryLockError::WouldBlock) = GFX_ACTIVE.try_lock() {
+            if use_stderr {
+                print_to_stderr(name, panic_info);
+            }
 
-                let payload = format!("thread '{name}' {panic_info}");
+            let payload = format!("thread '{name}' {panic_info}");
 
-                let mut popup = PopUp::new(Kind::Top);
+            let mut popup = PopUp::new(Kind::Top);
 
-                popup.set_text(&payload);
+            popup.set_text(&payload);
 
-                unsafe {
-                    popup.launch_unchecked();
-                }
-            }
-            _ => {
-                print_to_stderr(name, panic_info);
+            unsafe {
+                popup.launch_unchecked();
             }
+        } else {
+            print_to_stderr(name, panic_info);
         }
     }));
 

From d630c25926b194563807f458afb3344b859771f2 Mon Sep 17 00:00:00 2001
From: Fenrir <fenrirwolf@gmail.com>
Date: Sun, 25 Feb 2024 17:53:12 -0700
Subject: [PATCH 10/17] Check for APT init errors in panic hook

---
 ctru-rs/src/applets/error.rs | 4 +---
 1 file changed, 1 insertion(+), 3 deletions(-)

diff --git a/ctru-rs/src/applets/error.rs b/ctru-rs/src/applets/error.rs
index b723aa8b..92dc7e35 100644
--- a/ctru-rs/src/applets/error.rs
+++ b/ctru-rs/src/applets/error.rs
@@ -100,15 +100,13 @@ pub fn set_panic_hook(use_stderr: bool) {
     use std::sync::TryLockError;
 
     std::panic::set_hook(Box::new(move |panic_info| {
-        let _apt = Apt::new();
-
         let thread = std::thread::current();
 
         let name = thread.name().unwrap_or("<unnamed>");
 
         // 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) = GFX_ACTIVE.try_lock() {
+        if let (Err(TryLockError::WouldBlock), Ok(_apt)) = (GFX_ACTIVE.try_lock(), Apt::new()) {
             if use_stderr {
                 print_to_stderr(name, panic_info);
             }

From 5cec437e1d3f0fd62339d29db6fa05888b4237f9 Mon Sep 17 00:00:00 2001
From: Fenrir <fenrirwolf@gmail.com>
Date: Sun, 25 Feb 2024 18:06:48 -0700
Subject: [PATCH 11/17] Reuse default hook instead of custom print method

---
 ctru-rs/src/applets/error.rs | 30 ++++++++++++++----------------
 1 file changed, 14 insertions(+), 16 deletions(-)

diff --git a/ctru-rs/src/applets/error.rs b/ctru-rs/src/applets/error.rs
index 92dc7e35..67665ab4 100644
--- a/ctru-rs/src/applets/error.rs
+++ b/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 {

From 6da884e7b68c7a03ca898a97d4bb70bf11b56362 Mon Sep 17 00:00:00 2001
From: Fenrir <fenrirwolf@gmail.com>
Date: Sun, 25 Feb 2024 18:45:56 -0700
Subject: [PATCH 12/17] Use the previous panic hook instead of just the default

---
 ctru-rs/src/applets/error.rs | 21 +++++++++------------
 1 file changed, 9 insertions(+), 12 deletions(-)

diff --git a/ctru-rs/src/applets/error.rs b/ctru-rs/src/applets/error.rs
index 67665ab4..d57af557 100644
--- a/ctru-rs/src/applets/error.rs
+++ b/ctru-rs/src/applets/error.rs
@@ -89,19 +89,16 @@ impl PopUp {
 }
 
 /// 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.
+/// previously registered panic hook called along with the error applet message, which can be useful if you want
+/// to use input redirection to display panic messages over `3dslink` or `GDB`.
 ///
-/// 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) {
+/// If the `Gfx` service is not initialized during a panic, the error applet will not be displayed and the old
+/// panic hook will be called.
+pub fn set_panic_hook(call_old_hook: bool) {
     use crate::services::gfx::GFX_ACTIVE;
     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()
-    };
+    let old_hook = std::panic::take_hook();
 
     std::panic::set_hook(Box::new(move |panic_info| {
         let thread = std::thread::current();
@@ -111,8 +108,8 @@ pub fn set_panic_hook(call_default_hook: 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 call_default_hook {
-                default_hook(panic_info);
+            if call_old_hook {
+                old_hook(panic_info);
             }
 
             let payload = format!("thread '{name}' {panic_info}");
@@ -125,7 +122,7 @@ pub fn set_panic_hook(call_default_hook: bool) {
                 popup.launch_unchecked();
             }
         } else {
-            default_hook(panic_info);
+            old_hook(panic_info);
         }
     }));
 }

From ffbe6604a68cc496f289553f04106185211fa2bc Mon Sep 17 00:00:00 2001
From: Fenrir <fenrirwolf@gmail.com>
Date: Sun, 25 Feb 2024 19:09:28 -0700
Subject: [PATCH 13/17] Improve docs for set_panic_hook

---
 ctru-rs/src/applets/error.rs | 12 ++++++++----
 1 file changed, 8 insertions(+), 4 deletions(-)

diff --git a/ctru-rs/src/applets/error.rs b/ctru-rs/src/applets/error.rs
index d57af557..9bc66da4 100644
--- a/ctru-rs/src/applets/error.rs
+++ b/ctru-rs/src/applets/error.rs
@@ -88,12 +88,16 @@ impl PopUp {
     }
 }
 
-/// Sets a custom panic hook that uses the error applet to display panic messages. You can also choose to have the
-/// previously registered panic hook called along with the error applet message, which can be useful if you want
-/// to use input redirection to display panic messages over `3dslink` or `GDB`.
+/// Sets a custom [panic hook](https://doc.rust-lang.org/std/panic/fn.set_hook.html) that uses the error applet to display panic messages.
 ///
-/// If the `Gfx` service is not initialized during a panic, the error applet will not be displayed and the old
+/// You can also choose to have the previously registered panic hook called along with the error applet message, which can be useful
+/// if you want to use output redirection to display panic messages over `3dslink` or `GDB`.
+///
+/// If the [`Gfx`] service is not initialized during a panic, the error applet will not be displayed and the old
 /// panic hook will be called.
+///
+/// You can use [`std::panic::take_hook`](https://doc.rust-lang.org/std/panic/fn.take_hook.html) to unregister the panic hook
+/// set by this function.
 pub fn set_panic_hook(call_old_hook: bool) {
     use crate::services::gfx::GFX_ACTIVE;
     use std::sync::TryLockError;

From efbf91338082513cdbf1fb15eddb162ebf214433 Mon Sep 17 00:00:00 2001
From: Fenrir <fenrirwolf@gmail.com>
Date: Mon, 26 Feb 2024 02:45:51 -0700
Subject: [PATCH 14/17] Move error parsing code into launch_unchecked

---
 ctru-rs/src/applets/error.rs | 23 ++++++++++++-----------
 1 file changed, 12 insertions(+), 11 deletions(-)

diff --git a/ctru-rs/src/applets/error.rs b/ctru-rs/src/applets/error.rs
index 9bc66da4..6450a41b 100644
--- a/ctru-rs/src/applets/error.rs
+++ b/ctru-rs/src/applets/error.rs
@@ -1,6 +1,7 @@
 //! Error applet
 //!
 //! This applet displays error text as a pop-up message on the lower screen.
+
 use crate::services::{apt::Apt, gfx::Gfx};
 
 use ctru_sys::errorConf;
@@ -66,7 +67,16 @@ impl PopUp {
     /// Launches the error applet.
     #[doc(alias = "errorDisp")]
     pub fn launch(&mut self, _apt: &Apt, _gfx: &Gfx) -> Result<(), Error> {
-        unsafe { ctru_sys::errorDisp(self.state.as_mut()) }
+        unsafe { self.launch_unchecked() }
+    }
+
+    /// Launches the error applet without requiring an [`Apt`] or [`Gfx`] handle.
+    ///
+    /// # Safety
+    ///
+    /// Causes undefined behavior if the aforementioned services are not actually active when the applet launches.
+    unsafe fn launch_unchecked(&mut self) -> Result<(), Error> {
+        unsafe { ctru_sys::errorDisp(self.state.as_mut()) };
 
         match self.state.returnCode {
             ctru_sys::ERROR_NONE | ctru_sys::ERROR_SUCCESS => Ok(()),
@@ -77,15 +87,6 @@ impl PopUp {
             _ => Err(Error::Unknown),
         }
     }
-
-    /// Launches the error applet without requiring an [`Apt`] or [`Gfx`] handle.
-    ///
-    /// # Safety
-    ///
-    /// Causes undefined behavior if the aforementioned services are not actually active when the applet launches.
-    unsafe fn launch_unchecked(&mut self) {
-        unsafe { ctru_sys::errorDisp(self.state.as_mut()) };
-    }
 }
 
 /// Sets a custom [panic hook](https://doc.rust-lang.org/std/panic/fn.set_hook.html) that uses the error applet to display panic messages.
@@ -123,7 +124,7 @@ pub fn set_panic_hook(call_old_hook: bool) {
             popup.set_text(&payload);
 
             unsafe {
-                popup.launch_unchecked();
+                let _ = popup.launch_unchecked();
             }
         } else {
             old_hook(panic_info);

From 559c757d35cbd5ad741b0bb434bcf2af09dd4882 Mon Sep 17 00:00:00 2001
From: Fenrir <fenrirwolf@gmail.com>
Date: Mon, 26 Feb 2024 03:22:22 -0700
Subject: [PATCH 15/17] Refactor some code and improve documentation

---
 ctru-rs/src/applets/error.rs | 55 +++++++++++++++++++++---------------
 ctru-sys/src/lib.rs          |  4 +--
 2 files changed, 34 insertions(+), 25 deletions(-)

diff --git a/ctru-rs/src/applets/error.rs b/ctru-rs/src/applets/error.rs
index 6450a41b..44fff081 100644
--- a/ctru-rs/src/applets/error.rs
+++ b/ctru-rs/src/applets/error.rs
@@ -1,4 +1,4 @@
-//! Error applet
+//! Error applet.
 //!
 //! This applet displays error text as a pop-up message on the lower screen.
 
@@ -12,15 +12,15 @@ pub struct PopUp {
     state: Box<errorConf>,
 }
 
-/// The kind of error applet to display.
+/// Determines whether the Error applet will use word wrapping when displaying a message.
 #[doc(alias = "errorType")]
 #[derive(Copy, Clone, Debug, PartialEq, Eq)]
 #[repr(u32)]
-pub enum Kind {
-    /// Error text is centered in the error applet window.
-    Center = ctru_sys::ERROR_TEXT,
-    /// Error text starts at the top of the error applet window.
-    Top = ctru_sys::ERROR_TEXT_WORD_WRAP,
+pub enum WordWrap {
+    /// Error text is centered in the error applet window and does not use word wrapping.
+    Disabled = ctru_sys::ERROR_TEXT,
+    /// Error text starts at the top of the error applet window and uses word wrapping.
+    Enabled = ctru_sys::ERROR_TEXT_WORD_WRAP,
 }
 
 /// Error returned by an unsuccessful [`PopUp::launch()`].
@@ -41,17 +41,22 @@ pub enum Error {
 }
 
 impl PopUp {
-    /// Initialize the error applet with the provided text kind.
+    /// Initializes the error applet with the provided word wrap setting.
     #[doc(alias = "errorInit")]
-    pub fn new(kind: Kind) -> Self {
+    pub fn new(word_wrap: WordWrap) -> Self {
         let mut state = Box::<errorConf>::default();
 
-        unsafe { ctru_sys::errorInit(state.as_mut(), kind as _, 0) };
+        unsafe { ctru_sys::errorInit(state.as_mut(), word_wrap as _, 0) };
 
         Self { state }
     }
 
     /// Sets the error text to display.
+    ///
+    /// # Notes
+    ///
+    /// Messages that are too large will be truncated. The exact number of characters displayed can vary depending on factors such as
+    /// the length of individual words in the message and the chosen word wrap setting.
     #[doc(alias = "errorText")]
     pub fn set_text(&mut self, text: &str) {
         for (idx, code_unit) in text
@@ -74,7 +79,7 @@ impl PopUp {
     ///
     /// # Safety
     ///
-    /// Causes undefined behavior if the aforementioned services are not actually active when the applet launches.
+    /// Potentially leads to undefined behavior if the aforementioned services are not actually active when the applet launches.
     unsafe fn launch_unchecked(&mut self) -> Result<(), Error> {
         unsafe { ctru_sys::errorDisp(self.state.as_mut()) };
 
@@ -91,14 +96,18 @@ impl PopUp {
 
 /// Sets a custom [panic hook](https://doc.rust-lang.org/std/panic/fn.set_hook.html) that uses the error applet to display panic messages.
 ///
-/// You can also choose to have the previously registered panic hook called along with the error applet message, which can be useful
+/// You can also choose to have the previously registered panic hook called along with the error applet popup, which can be useful
 /// if you want to use output redirection to display panic messages over `3dslink` or `GDB`.
 ///
-/// If the [`Gfx`] service is not initialized during a panic, the error applet will not be displayed and the old
-/// panic hook will be called.
-///
 /// You can use [`std::panic::take_hook`](https://doc.rust-lang.org/std/panic/fn.take_hook.html) to unregister the panic hook
 /// set by this function.
+///
+/// # Notes
+///
+/// * If the [`Gfx`] service is not initialized during a panic, the error applet will not be displayed and the old panic hook will be called.
+///
+/// * As mentioned in [`PopUp::set_text`], the error applet can only display a finite number of characters and so panic messages that are too long
+/// can potentially end up being truncated. Consider using this hook along with the default hook so that you can capture full panic messages via stderr.
 pub fn set_panic_hook(call_old_hook: bool) {
     use crate::services::gfx::GFX_ACTIVE;
     use std::sync::TryLockError;
@@ -106,22 +115,22 @@ pub fn set_panic_hook(call_old_hook: bool) {
     let old_hook = std::panic::take_hook();
 
     std::panic::set_hook(Box::new(move |panic_info| {
-        let thread = std::thread::current();
-
-        let name = thread.name().unwrap_or("<unnamed>");
-
         // If we get a `WouldBlock` error, we know that the `Gfx` service has been initialized.
-        // Otherwise fallback to printing over stderr.
+        // Otherwise fallback to using the old panic hook.
         if let (Err(TryLockError::WouldBlock), Ok(_apt)) = (GFX_ACTIVE.try_lock(), Apt::new()) {
             if call_old_hook {
                 old_hook(panic_info);
             }
 
-            let payload = format!("thread '{name}' {panic_info}");
+            let thread = std::thread::current();
+
+            let name = thread.name().unwrap_or("<unnamed>");
+
+            let message = format!("thread '{name}' {panic_info}");
 
-            let mut popup = PopUp::new(Kind::Top);
+            let mut popup = PopUp::new(WordWrap::Enabled);
 
-            popup.set_text(&payload);
+            popup.set_text(&message);
 
             unsafe {
                 let _ = popup.launch_unchecked();
diff --git a/ctru-sys/src/lib.rs b/ctru-sys/src/lib.rs
index 39484a36..5a60de24 100644
--- a/ctru-sys/src/lib.rs
+++ b/ctru-sys/src/lib.rs
@@ -21,6 +21,7 @@ pub use result::*;
 // Libctru's `errorConf` struct contains two enums that depend on this narrowing property for size and alignment purposes,
 // and since `bindgen` generates all enums with `c_int` sizing, we have to blocklist those types and manually define them
 // here with the proper size.
+pub type errorReturnCode = libc::c_schar;
 pub const ERROR_UNKNOWN: errorReturnCode = -1;
 pub const ERROR_NONE: errorReturnCode = 0;
 pub const ERROR_SUCCESS: errorReturnCode = 1;
@@ -28,11 +29,10 @@ pub const ERROR_NOT_SUPPORTED: errorReturnCode = 2;
 pub const ERROR_HOME_BUTTON: errorReturnCode = 10;
 pub const ERROR_SOFTWARE_RESET: errorReturnCode = 11;
 pub const ERROR_POWER_BUTTON: errorReturnCode = 12;
-pub type errorReturnCode = libc::c_schar;
 
+pub type errorScreenFlag = libc::c_char;
 pub const ERROR_NORMAL: errorScreenFlag = 0;
 pub const ERROR_STEREO: errorScreenFlag = 1;
-pub type errorScreenFlag = libc::c_char;
 
 include!(concat!(env!("OUT_DIR"), "/bindings.rs"));
 

From b967440eb15f37c2257963a425239257aecfe03f Mon Sep 17 00:00:00 2001
From: Fenrir <fenrirwolf@gmail.com>
Date: Mon, 26 Feb 2024 19:36:33 -0700
Subject: [PATCH 16/17] properly handle nul termination in set_text

---
 ctru-rs/src/applets/error.rs | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/ctru-rs/src/applets/error.rs b/ctru-rs/src/applets/error.rs
index 44fff081..8e323bef 100644
--- a/ctru-rs/src/applets/error.rs
+++ b/ctru-rs/src/applets/error.rs
@@ -61,8 +61,8 @@ impl PopUp {
     pub fn set_text(&mut self, text: &str) {
         for (idx, code_unit) in text
             .encode_utf16()
-            .chain(std::iter::once(0))
             .take(self.state.Text.len() - 1)
+            .chain(std::iter::once(0))
             .enumerate()
         {
             self.state.Text[idx] = code_unit;

From 9396939d648ffb903deba94a94d49c707d0281b3 Mon Sep 17 00:00:00 2001
From: Fenrir <fenrirwolf@gmail.com>
Date: Tue, 27 Feb 2024 00:03:08 -0700
Subject: [PATCH 17/17] Error messages don't actually get truncated, false
 alarm everybody

---
 ctru-rs/src/applets/error.rs | 7 ++-----
 1 file changed, 2 insertions(+), 5 deletions(-)

diff --git a/ctru-rs/src/applets/error.rs b/ctru-rs/src/applets/error.rs
index 8e323bef..84dc3e7d 100644
--- a/ctru-rs/src/applets/error.rs
+++ b/ctru-rs/src/applets/error.rs
@@ -55,8 +55,8 @@ impl PopUp {
     ///
     /// # Notes
     ///
-    /// Messages that are too large will be truncated. The exact number of characters displayed can vary depending on factors such as
-    /// the length of individual words in the message and the chosen word wrap setting.
+    /// The text will be converted to UTF-16 for display with the applet, and the message will be truncated if it exceeds
+    /// 1900 UTF-16 code units in length after conversion.
     #[doc(alias = "errorText")]
     pub fn set_text(&mut self, text: &str) {
         for (idx, code_unit) in text
@@ -105,9 +105,6 @@ impl PopUp {
 /// # Notes
 ///
 /// * If the [`Gfx`] service is not initialized during a panic, the error applet will not be displayed and the old panic hook will be called.
-///
-/// * As mentioned in [`PopUp::set_text`], the error applet can only display a finite number of characters and so panic messages that are too long
-/// can potentially end up being truncated. Consider using this hook along with the default hook so that you can capture full panic messages via stderr.
 pub fn set_panic_hook(call_old_hook: bool) {
     use crate::services::gfx::GFX_ACTIVE;
     use std::sync::TryLockError;