3 files changed, 34 insertions, 23 deletions
diff --git a/ext/js/background/backend.js b/ext/js/background/backend.js
index c797bbf5..af847610 100644
--- a/ext/js/background/backend.js
+++ b/ext/js/background/backend.js
@@ -1066,7 +1066,7 @@ class Backend {
             if (
                 dictionaryEntries.length > 0 &&
                 originalTextLength > 0 &&
-                (originalTextLength !== character.length || this._japaneseUtil.isCodePointJapanese(codePoint))
+                (originalTextLength !== character.length || jp.isCodePointJapanese(codePoint))
             ) {
                 previousUngroupedSegment = null;
                 const {headwords: [{term, reading}]} = dictionaryEntries[0];
diff --git a/ext/js/display/query-parser.js b/ext/js/display/query-parser.js
index 0acf6ec8..cbcf7cff 100644
--- a/ext/js/display/query-parser.js
+++ b/ext/js/display/query-parser.js
@@ -208,8 +208,6 @@ class QueryParser extends EventDispatcher {
     }
 
     _createParseResult(data) {
-        const jp = this._japaneseUtil;
-        const readingMode = this._readingMode;
         const fragment = document.createDocumentFragment();
         for (const term of data) {
             const termNode = document.createElement('span');
@@ -218,7 +216,7 @@ class QueryParser extends EventDispatcher {
                 if (reading.length === 0) {
                     termNode.appendChild(document.createTextNode(text));
                 } else {
-                    const reading2 = jp.convertReading(text, reading, readingMode);
+                    const reading2 = this._convertReading(text, reading);
                     termNode.appendChild(this._createSegment(text, reading2));
                 }
             }
@@ -245,4 +243,26 @@ class QueryParser extends EventDispatcher {
 
         return segmentNode;
     }
+
+    _convertReading(term, reading) {
+        switch (this._readingMode) {
+            case 'hiragana':
+                return this._japaneseUtil.convertKatakanaToHiragana(reading);
+            case 'katakana':
+                return this._japaneseUtil.convertHiraganaToKatakana(reading);
+            case 'romaji':
+                if (this._japaneseUtil.convertToRomajiSupported()) {
+                    if (reading.length > 0) {
+                        return this._japaneseUtil.convertToRomaji(reading);
+                    } else if (this._japaneseUtil.isStringEntirelyKana(term)) {
+                        return this._japaneseUtil.convertToRomaji(term);
+                    }
+                }
+                return reading;
+            case 'none':
+                return '';
+            default:
+                return reading;
+        }
+    }
 }
diff --git a/ext/js/language/japanese-util.js b/ext/js/language/japanese-util.js
index 7ee726b2..9d7ad0d8 100644
--- a/ext/js/language/japanese-util.js
+++ b/ext/js/language/japanese-util.js
@@ -277,6 +277,10 @@ const JapaneseUtil = (() => {
             return this._getWanakana().toKana(text);
         }
 
+        convertToKanaSupported() {
+            return this._wanakana !== null;
+        }
+
         convertKatakanaToHiragana(text) {
             let result = '';
             const offset = (HIRAGANA_CONVERSION_RANGE[0] - KATAKANA_CONVERSION_RANGE[0]);
@@ -315,25 +319,8 @@ const JapaneseUtil = (() => {
             return wanakana.toRomaji(text);
         }
 
-        convertReading(term, reading, readingMode) {
-            switch (readingMode) {
-                case 'hiragana':
-                    return this.convertKatakanaToHiragana(reading);
-                case 'katakana':
-                    return this.convertHiraganaToKatakana(reading);
-                case 'romaji':
-                    if (reading.length > 0) {
-                        return this.convertToRomaji(reading);
-                    } else if (this.isStringEntirelyKana(term)) {
-                        return this.convertToRomaji(term);
-                    } else {
-                        return reading;
-                    }
-                case 'none':
-                    return '';
-                default:
-                    return reading;
-            }
+        convertToRomajiSupported() {
+            return this._wanakana !== null;
         }
 
         convertNumericToFullWidth(text) {
@@ -426,6 +413,10 @@ const JapaneseUtil = (() => {
             return result;
         }
 
+        convertAlphabeticToKanaSupported() {
+            return this._wanakana !== null;
+        }
+
         // Furigana distribution
 
         distributeFurigana(term, reading) {