From 21a48ac735f9f2f5e4384cb84e756897f07da61c Mon Sep 17 00:00:00 2001
From: FredApps <153173854+FredApps@users.noreply.github.com>
Date: Sun, 1 Nov 2026 12:54:00 +0100
Subject: [PATCH] fix(ui): finish font discovery when its worker panics

Contain discovery panics and publish the empty result so the font menu leaves its pending state. A synthetic panic regression fails when containment is removed.

Co-Authored-By: Codex GPT-6.1 <noreply@openai.com>
---
 crates/ui-egui/src/workflows/files.rs | 17 ++++++++++++++++-
 1 file changed, 16 insertions(+), 1 deletion(-)

diff --git a/crates/ui-egui/src/workflows/files.rs b/crates/ui-egui/src/workflows/files.rs
index a9313a4714..17870e5b1a 100644
--- a/crates/ui-egui/src/workflows/files.rs
+++ b/crates/ui-egui/src/workflows/files.rs
@@ -28,6 +28,13 @@ pub enum FilePurpose {
     RedactWords,
 }
 
+#[cfg(not(target_arch = "wasm32"))]
+fn discover_fonts_safely(
+    discover: impl FnOnce() -> Vec<pdfcraft_engine::text_fonts::FontFile> + std::panic::UnwindSafe,
+) -> Vec<pdfcraft_engine::text_fonts::FontFile> {
+    std::panic::catch_unwind(discover).unwrap_or_default()
+}
+
 /// Discover installed document fonts off the GUI thread, only when the picker is opened.
 #[cfg(not(target_arch = "wasm32"))]
 pub(crate) fn installed_font_files(ctx: &egui::Context) -> Option<Vec<pdfcraft_engine::text_fonts::FontFile>> {
@@ -41,7 +48,7 @@ pub(crate) fn installed_font_files(ctx: &egui::Context) -> Option<Vec<pdfcraft_e
         if std::thread::Builder::new()
             .name("document-font-discovery".into())
             .spawn(move || {
-                let fonts = pdfcraft_engine::text_fonts::discover(&pdfcraft_engine::text_fonts::installed_directories());
+                let fonts = discover_fonts_safely(|| pdfcraft_engine::text_fonts::discover(&pdfcraft_engine::text_fonts::installed_directories()));
                 if let Ok(mut result) = result.lock() {
                     *result = Some(fonts);
                 }
@@ -1177,3 +1184,11 @@ mod stem_tests {
         out
     }
 }
+
+#[cfg(all(test, not(target_arch = "wasm32")))]
+mod font_scan_tests {
+    #[test]
+    fn a_panicking_font_scan_finishes_with_an_empty_list() {
+        assert!(super::discover_fonts_safely(|| panic!("synthetic font scan failure")).is_empty());
+    }
+}