fix(android): avoid rsproperties panic on startup, closes #3922 (#3942)

`rsproperties::get` panics when it can't open or parse the
`/dev/__properties__` layout (documented behavior of the crate).
On some older/unusual Android builds (e.g. MediaTek Android 8.1 on
Xiaomi Mipad), this aborts the app with SIGABRT before the main
window is created.

Replace the crate with a direct FFI call to Android's native
`__system_property_get`, which has existed since the earliest
Android versions and returns an error code instead of panicking.

Co-authored-by: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

Cargo.lock

@@ -17,6 +17,7 @@ dependencies = [
  "discord-rich-presence",
  "futures",
  "futures-util",
+ "libc",
  "log",
  "objc",
  "objc-foundation",
@@ -27,7 +28,6 @@ dependencies = [
  "rand 0.8.6",
  "read-progress-stream",
  "reqwest 0.12.28",
- "rsproperties",
  "serde",
  "serde_json",
  "tauri",
@@ -5081,12 +5081,6 @@ version = "0.1.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "925383efa346730478fb4838dbe9137d2a47675ad789c546d150a6e1dd4ab31c"
 
-[[package]]
-name = "pretty-hex"
-version = "0.4.2"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "9a65843dfefbafd3c879c683306959a6de478443ffe9c9adf02f5976432402d7"
-
 [[package]]
 name = "prettyplease"
 version = "0.2.37"
@@ -5842,20 +5836,6 @@ dependencies = [
  "byteorder",
 ]
 
-[[package]]
-name = "rsproperties"
-version = "0.3.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "b98d55abde44982a00d67a84809166ea8f5c143abc86818f555485f19766cfe4"
-dependencies = [
- "log",
- "pretty-hex",
- "rustix 1.1.4",
- "thiserror 2.0.18",
- "zerocopy",
- "zerocopy-derive",
-]
-
 [[package]]
 name = "rust-ini"
 version = "0.21.3"

apps/readest-app/src-tauri/Cargo.toml

@@ -81,4 +81,4 @@ tauri-plugin-window-state = "2"
 discord-rich-presence = "1.0.0"
 
 [target.'cfg(target_os = "android")'.dependencies]
-rsproperties = "0.3"
+libc = "0.2"

apps/readest-app/src-tauri/src/android/eink.rs

@@ -46,9 +46,21 @@ const EINK_MODELS: &[&str] = &[
 ];
 
 fn get_system_property(prop: &str) -> Option<String> {
-    rsproperties::get::<String>(prop)
-        .ok()
-        .filter(|s| !s.is_empty())
+    use std::ffi::CString;
+    let name = CString::new(prop).ok()?;
+    let mut buf = [0u8; libc::PROP_VALUE_MAX as usize];
+    // SAFETY: __system_property_get writes at most PROP_VALUE_MAX bytes (including the
+    // trailing NUL) into the provided buffer and returns the number of bytes written
+    // excluding the NUL. `name` is a valid NUL-terminated C string for the duration
+    // of the call.
+    let len = unsafe {
+        libc::__system_property_get(name.as_ptr(), buf.as_mut_ptr() as *mut libc::c_char)
+    };
+    if len <= 0 {
+        return None;
+    }
+    let value = std::str::from_utf8(&buf[..len as usize]).ok()?;
+    (!value.is_empty()).then(|| value.to_owned())
 }
 
 /// Check if the current Android device is an e-ink device.