[file_sys] Avoid crash on empty NACP language entries (#4062)

This fixes an Android game library scan crash when reading XCI title metadata with empty or incomplete NACP language entries.

Previously, NACP::GetLanguageEntry() could fall back to:

language_entries.at(static_cast<u8>(Language::AmericanEnglish))

When language_entries was empty, this threw std::out_of_range and aborted the Android scan thread.

The new fallback preserves the existing lookup order:
1. preferred language entry with non-empty application name
2. any entry with non-empty application name
3. first available entry
4. static empty LanguageEntry if no entries exist

Tested locally with a Mainline RelWithDebInfo APK on Odin3 Android 15 using a large external TF-card ROM directory. The previous build crashed during fresh ROM scan; the patched build completes scanning normally.

Related my issue:
https://github.com/eden-emulator/Issue-Reports/issues/500

Co-authored-by: bdm110 <bdm110@prontmail.com>
Reviewed-on: https://git.eden-emu.dev/eden-emu/eden/pulls/4062
Reviewed-by: Lizzie <lizzie@eden-emu.dev>
Reviewed-by: MaranBr <maranbr@eden-emu.dev>
Reviewed-by: crueter <crueter@eden-emu.dev>

1 files changed, 13 insertions, 6 deletions

diff --git a/src/core/file_sys/control_metadata.cpp b/src/core/file_sys/control_metadata.cpp
index f86d22d627..2e182f1749 100644
--- a/src/core/file_sys/control_metadata.cpp
+++ b/src/core/file_sys/control_metadata.cpp
@@ -128,25 +128,32 @@ const LanguageEntry& NACP::GetLanguageEntry() const {
         case Settings::Language::Russian: return Language::Russian;
         case Settings::Language::Spanish: return Language::Spanish;
         case Settings::Language::SpanishLatin: return Language::LatinAmericanSpanish;
-        case Settings::Language::Taiwanese: return Language::SimplifiedChinese;
+        case Settings::Language::Taiwanese: return Language::TraditionalChinese;
         case Settings::Language::Thai: return Language::Thai;
         case Settings::Language::Polish: return Language::Polish;
         default: return Language::AmericanEnglish;
         }
     }();
 
-    u32 index = u32(language);
+    const auto index = static_cast<size_t>(language);
 
-    if (index < language_entries.size() && !language_entries[index].GetApplicationName().empty()) {
+    if (index < language_entries.size() &&
+        !language_entries[index].GetApplicationName().empty()) {
         return language_entries[index];
     }
 
     for (const auto& entry : language_entries) {
-        if (!entry.GetApplicationName().empty())
-          return entry;
+        if (!entry.GetApplicationName().empty()) {
+            return entry;
+        }
+    }
+
+    if (!language_entries.empty()) {
+        return language_entries.front();
     }
 
-    return language_entries.at(static_cast<u8>(Language::AmericanEnglish));
+    static const LanguageEntry empty_entry{};
+    return empty_entry;
 }
 
 std::vector<std::string> NACP::GetApplicationNames() const {