[VFS] Fix STFS language slot resolution

Stop scanning past the max stfs values, and dedup english fallback logic
as well as fix the one place where it diverged and was writing japanese

src/xenia/vfs/devices/stfs_xbox.h

@@ -12,6 +12,7 @@
 
 #include <time.h>
 
+#include "xenia/base/logging.h"
 #include "xenia/base/string_util.h"
 #include "xenia/kernel/util/xex2_info.h"
 #include "xenia/xbox.h"
@@ -368,27 +369,33 @@ struct XContentMetadata {
     char16_t chars[kNumLanguagesV2 - kNumLanguagesV1][128];
   } description_ex_raw;
 
-  std::u16string display_name(XLanguage language) const {
-    uint32_t lang_id =
-        language == XLanguage::kInvalid ? 1 : uint32_t(language) - 1;
-
+  // Resolves a system language to an STFS metadata slot index. STFS headers
+  // only hold kNumLanguagesV2 languages; the extended languages and kInvalid
+  // have no slot and resolve to English. Warns only for values outside the
+  // enum, which signal a bad language id rather than a known format limit.
+  static uint32_t language_slot(XLanguage language) {
+    uint32_t lang_id = uint32_t(language) - 1;
     if (lang_id >= kNumLanguagesV2) {
-      assert_always();
-      // no room for this lang, read from english slot..
+      if (uint32_t(language) >= uint32_t(XLanguage::kMaxLanguages)) {
+        XELOGW("STFS metadata: invalid language {}, using English",
+               uint32_t(language));
+      }
       lang_id = uint32_t(XLanguage::kEnglish) - 1;
     }
+    return lang_id;
+  }
+
+  std::u16string display_name(XLanguage language) const {
+    uint32_t lang_id = language_slot(language);
 
     const be<uint16_t>* str = 0;
-    if (lang_id >= 0 && lang_id < kNumLanguagesV1) {
+    if (lang_id < kNumLanguagesV1) {
       str = display_name_raw.uint[lang_id];
-    } else if (lang_id >= kNumLanguagesV1 && lang_id < kNumLanguagesV2 &&
-               metadata_version >= 2) {
+    } else if (lang_id < kNumLanguagesV2 && metadata_version >= 2) {
       str = display_name_ex_raw.uint[lang_id - kNumLanguagesV1];
     }
 
     if (!str) {
-      // Invalid language ID?
-      assert_always();
       return u"";
     }
 
@@ -396,25 +403,16 @@ struct XContentMetadata {
   }
 
   std::u16string description(XLanguage language) const {
-    uint32_t lang_id = uint32_t(language) - 1;
-
-    if (lang_id >= kNumLanguagesV2) {
-      assert_always();
-      // no room for this lang, read from english slot..
-      lang_id = uint32_t(XLanguage::kEnglish) - 1;
-    }
+    uint32_t lang_id = language_slot(language);
 
     const be<uint16_t>* str = 0;
-    if (lang_id >= 0 && lang_id < kNumLanguagesV1) {
+    if (lang_id < kNumLanguagesV1) {
       str = description_raw.uint[lang_id];
-    } else if (lang_id >= kNumLanguagesV1 && lang_id < kNumLanguagesV2 &&
-               metadata_version >= 2) {
+    } else if (lang_id < kNumLanguagesV2 && metadata_version >= 2) {
       str = description_ex_raw.uint[lang_id - kNumLanguagesV1];
     }
 
     if (!str) {
-      // Invalid language ID?
-      assert_always();
       return u"";
     }
 
@@ -430,25 +428,16 @@ struct XContentMetadata {
   }
 
   bool set_display_name(XLanguage language, const std::u16string_view value) {
-    uint32_t lang_id = uint32_t(language) - 1;
-
-    if (lang_id >= kNumLanguagesV2) {
-      assert_always();
-      // no room for this lang, store in english slot..
-      lang_id = uint32_t(XLanguage::kEnglish) - 1;
-    }
+    uint32_t lang_id = language_slot(language);
 
     char16_t* str = 0;
-    if (lang_id >= 0 && lang_id < kNumLanguagesV1) {
+    if (lang_id < kNumLanguagesV1) {
       str = display_name_raw.chars[lang_id];
-    } else if (lang_id >= kNumLanguagesV1 && lang_id < kNumLanguagesV2 &&
-               metadata_version >= 2) {
+    } else if (lang_id < kNumLanguagesV2 && metadata_version >= 2) {
       str = display_name_ex_raw.chars[lang_id - kNumLanguagesV1];
     }
 
     if (!str) {
-      // Invalid language ID?
-      assert_always();
       return false;
     }
 
@@ -458,25 +447,16 @@ struct XContentMetadata {
   }
 
   bool set_description(XLanguage language, const std::u16string_view value) {
-    uint32_t lang_id = uint32_t(language) - 1;
-
-    if (lang_id >= kNumLanguagesV2) {
-      assert_always();
-      // no room for this lang, store in english slot..
-      lang_id = uint32_t(XLanguage::kEnglish) - 1;
-    }
+    uint32_t lang_id = language_slot(language);
 
     char16_t* str = 0;
-    if (lang_id >= 0 && lang_id < kNumLanguagesV1) {
+    if (lang_id < kNumLanguagesV1) {
       str = description_raw.chars[lang_id];
-    } else if (lang_id >= kNumLanguagesV1 && lang_id < kNumLanguagesV2 &&
-               metadata_version >= 2) {
+    } else if (lang_id < kNumLanguagesV2 && metadata_version >= 2) {
       str = description_ex_raw.chars[lang_id - kNumLanguagesV1];
     }
 
     if (!str) {
-      // Invalid language ID?
-      assert_always();
       return false;
     }
 

src/xenia/vfs/stfs_metadata.cc

@@ -95,7 +95,7 @@ std::optional<StfsMetadata> ExtractStfsMetadata(
     }
     if (str.empty()) {
       for (uint32_t i = uint32_t(XLanguage::kEnglish);
-           i < uint32_t(XLanguage::kMaxLanguages); ++i) {
+           i <= content_meta.kNumLanguagesV2; ++i) {
         auto candidate = static_cast<XLanguage>(i);
         if (candidate == language || candidate == XLanguage::kEnglish) {
           continue;