fix(linux): prefer native Wayland for AppImage webviews

src-tauri/src/lib.rs

@@ -37,6 +37,7 @@ use crate::core::{
 
 #[cfg_attr(mobile, tauri::mobile_entry_point)]
 pub fn run() {
+    platform::prepare_appimage_wayland_backend();
     portable_updater::schedule_cleanup_from_environment();
     let runtime = runtime::resolve().expect("failed to resolve runtime paths");
     runtime::prepare_webview_environment(&runtime);

src-tauri/src/platform/linux_appimage_wayland.rs

@@ -0,0 +1,66 @@
+const PREFERRED_APPIMAGE_WAYLAND_BACKENDS: &str = "wayland,x11";
+
+pub fn prepare_appimage_wayland_backend() {
+    let is_appimage = env_var_is_non_empty("APPIMAGE") || env_var_is_non_empty("APPDIR");
+    let has_wayland_display = env_var_is_non_empty("WAYLAND_DISPLAY");
+    let current_backend = std::env::var("GDK_BACKEND").ok();
+
+    let Some(backend) =
+        preferred_gdk_backend(is_appimage, has_wayland_display, current_backend.as_deref())
+    else {
+        return;
+    };
+
+    // SAFETY: `run()` calls this synchronously before Tauri/GTK initialization and before
+    // NyaTerm starts worker threads. Changing the process environment is therefore not racing
+    // with environment reads in other threads.
+    unsafe {
+        std::env::set_var("GDK_BACKEND", backend);
+    }
+}
+
+fn env_var_is_non_empty(name: &str) -> bool {
+    std::env::var_os(name).is_some_and(|value| !value.is_empty())
+}
+
+fn preferred_gdk_backend(
+    is_appimage: bool,
+    has_wayland_display: bool,
+    current_backend: Option<&str>,
+) -> Option<&'static str> {
+    // Tauri's AppImage GTK hook currently forces GDK_BACKEND=x11. On modern Wayland
+    // sessions that sends WebKitGTK through XWayland and can leave the webview unable to
+    // receive pointer/keyboard input. Prefer native Wayland while retaining X11 as a fallback.
+    (is_appimage && has_wayland_display && current_backend == Some("x11"))
+        .then_some(PREFERRED_APPIMAGE_WAYLAND_BACKENDS)
+}
+
+#[cfg(test)]
+mod tests {
+    use super::{PREFERRED_APPIMAGE_WAYLAND_BACKENDS, preferred_gdk_backend};
+
+    #[test]
+    fn prefers_wayland_for_appimage_when_tauri_forced_x11() {
+        assert_eq!(
+            preferred_gdk_backend(true, true, Some("x11")),
+            Some(PREFERRED_APPIMAGE_WAYLAND_BACKENDS)
+        );
+    }
+
+    #[test]
+    fn leaves_non_appimage_linux_packages_unchanged() {
+        assert_eq!(preferred_gdk_backend(false, true, Some("x11")), None);
+    }
+
+    #[test]
+    fn leaves_x11_sessions_unchanged() {
+        assert_eq!(preferred_gdk_backend(true, false, Some("x11")), None);
+    }
+
+    #[test]
+    fn preserves_existing_non_x11_backend_selection() {
+        assert_eq!(preferred_gdk_backend(true, true, Some("wayland")), None);
+        assert_eq!(preferred_gdk_backend(true, true, Some("wayland,x11")), None);
+        assert_eq!(preferred_gdk_backend(true, true, None), None);
+    }
+}

src-tauri/src/platform/mod.rs

@@ -1,6 +1,15 @@
 #[cfg(windows)]
 mod windows_external_drop;
 
+#[cfg(target_os = "linux")]
+mod linux_appimage_wayland;
+
+#[cfg(target_os = "linux")]
+pub use linux_appimage_wayland::prepare_appimage_wayland_backend;
+
+#[cfg(not(target_os = "linux"))]
+pub fn prepare_appimage_wayland_backend() {}
+
 #[cfg(windows)]
 pub use windows_external_drop::install_external_file_drop_bridge;