5 files changed, 60 insertions, 11 deletions
diff --git a/ext/bg/js/database.js b/ext/bg/js/database.js
index 2d309f85..c6717560 100644
--- a/ext/bg/js/database.js
+++ b/ext/bg/js/database.js
@@ -332,9 +332,11 @@ class Database {
         return result;
     }
 
-    async importDictionary(archive, progressCallback, exceptions) {
+    async importDictionary(archive, progressCallback, exceptions, details) {
         this.validate();
 
+        const prefixWildcardsSupported = details.prefixWildcardsSupported;
+
         const maxTransactionLength = 1000;
         const bulkAdd = async (objectStoreName, items, total, current) => {
             const db = this.db;
@@ -389,9 +391,7 @@ class Database {
                         rules,
                         score,
                         glossary,
-                        dictionary: summary.title,
-                        expressionReverse: stringReverse(expression),
-                        readingReverse: stringReverse(reading)
+                        dictionary: summary.title
                     });
                 }
             } else {
@@ -405,13 +405,18 @@ class Database {
                         glossary,
                         sequence,
                         termTags,
-                        dictionary: summary.title,
-                        expressionReverse: stringReverse(expression),
-                        readingReverse: stringReverse(reading)
+                        dictionary: summary.title
                     });
                 }
             }
 
+            if (prefixWildcardsSupported) {
+                for (const row of rows) {
+                    row.expressionReverse = stringReverse(row.expression);
+                    row.readingReverse = stringReverse(row.reading);
+                }
+            }
+
             await bulkAdd('terms', rows, total, current);
         };
 
diff --git a/ext/bg/js/options.js b/ext/bg/js/options.js
index e53a8a13..2d13f6d9 100644
--- a/ext/bg/js/options.js
+++ b/ext/bg/js/options.js
@@ -378,7 +378,15 @@ function profileOptionsUpdateVersion(options) {
  * ]
  */
 
-const optionsVersionUpdates = [];
+const optionsVersionUpdates = [
+    (options) => {
+        options.global = {
+            database: {
+                prefixWildcardsSupported: false
+            }
+        };
+    }
+];
 
 function optionsUpdateVersion(options, defaultProfileOptions) {
     // Ensure profiles is an array
@@ -423,6 +431,11 @@ function optionsUpdateVersion(options, defaultProfileOptions) {
         profile.options = profileOptionsUpdateVersion(profile.options);
     }
 
+    // Version
+    if (typeof options.version !== 'number') {
+        options.version = 0;
+    }
+
     // Generic updates
     return optionsGenericApplyUpdates(options, optionsVersionUpdates);
 }
diff --git a/ext/bg/js/settings/dictionaries.js b/ext/bg/js/settings/dictionaries.js
index 065a8abc..926b05b7 100644
--- a/ext/bg/js/settings/dictionaries.js
+++ b/ext/bg/js/settings/dictionaries.js
@@ -356,6 +356,7 @@ async function dictSettingsInitialize() {
     document.querySelector('#dict-file-button').addEventListener('click', (e) => onDictionaryImportButtonClick(e), false);
     document.querySelector('#dict-file').addEventListener('change', (e) => onDictionaryImport(e), false);
     document.querySelector('#dict-main').addEventListener('change', (e) => onDictionaryMainChanged(e), false);
+    document.querySelector('#database-enable-prefix-wildcard-searches').addEventListener('change', (e) => onDatabaseEnablePrefixWildcardSearchesChanged(e), false);
 
     const optionsContext = getOptionsContext();
     const options = await apiOptionsGet(optionsContext);
@@ -366,6 +367,9 @@ async function dictSettingsInitialize() {
 async function onDictionaryOptionsChanged(options) {
     if (dictionaryUI === null) { return; }
     dictionaryUI.setOptionsDictionaries(options.dictionaries);
+
+    const optionsFull = await apiOptionsGetFull();
+    document.querySelector('#database-enable-prefix-wildcard-searches').checked = optionsFull.global.database.prefixWildcardsSupported;
 }
 
 async function onDatabaseUpdated(options) {
@@ -575,6 +579,12 @@ async function onDictionaryImport(e) {
         const exceptions = [];
         const files = [...e.target.files];
 
+        const optionsFull = await apiOptionsGetFull();
+
+        const importDetails = {
+            prefixWildcardsSupported: optionsFull.global.database.prefixWildcardsSupported
+        };
+
         for (let i = 0, ii = files.length; i < ii; ++i) {
             setProgress(0.0);
             if (ii > 1) {
@@ -582,7 +592,7 @@ async function onDictionaryImport(e) {
                 dictImportInfo.textContent = `(${i + 1} of ${ii})`;
             }
 
-            const summary = await utilDatabaseImport(files[i], updateProgress, exceptions);
+            const summary = await utilDatabaseImport(files[i], updateProgress, exceptions, importDetails);
             for (const options of toIterable(await getOptionsArray())) {
                 const dictionaryOptions = SettingsDictionaryListUI.createDictionaryOptions();
                 dictionaryOptions.enabled = true;
@@ -616,3 +626,12 @@ async function onDictionaryImport(e) {
         dictProgress.hide();
     }
 }
+
+
+async function onDatabaseEnablePrefixWildcardSearchesChanged(e) {
+    const optionsFull = await apiOptionsGetFull();
+    const v = !!e.target.checked;
+    if (optionsFull.global.database.prefixWildcardsSupported === v) { return; }
+    optionsFull.global.database.prefixWildcardsSupported = !!e.target.checked;
+    await settingsSaveOptions();
+}
diff --git a/ext/bg/js/util.js b/ext/bg/js/util.js
index 3dd5fd55..8175fdff 100644
--- a/ext/bg/js/util.js
+++ b/ext/bg/js/util.js
@@ -94,13 +94,13 @@ function utilDatabaseDeleteDictionary(dictionaryName, onProgress) {
     return utilBackend().translator.database.deleteDictionary(dictionaryName, onProgress);
 }
 
-async function utilDatabaseImport(data, progress, exceptions) {
+async function utilDatabaseImport(data, progress, exceptions, details) {
     // Edge cannot read data on the background page due to the File object
     // being created from a different window. Read on the same page instead.
     if (EXTENSION_IS_BROWSER_EDGE) {
         data = await utilReadFile(data);
     }
-    return utilBackend().translator.database.importDictionary(data, progress, exceptions);
+    return utilBackend().translator.database.importDictionary(data, progress, exceptions, details);
 }
 
 function utilReadFile(file) {
diff --git a/ext/bg/settings.html b/ext/bg/settings.html
index 1a61a290..ac19a020 100644
--- a/ext/bg/settings.html
+++ b/ext/bg/settings.html
@@ -491,6 +491,18 @@
                     <div hidden><input type="file" id="dict-file" accept=".zip,application/zip" multiple></div>
                 </div>
 
+                <div>
+                    <h3>Dictionary Options</h3>
+                </div>
+
+                <div class="checkbox">
+                    <label><input type="checkbox" id="database-enable-prefix-wildcard-searches"> Enable prefix wildcard searches</label>
+                    <p class="help-block">
+                        This option only applies to newly imported dictionaries.
+                        Enabling this option will also cause dictionary data to take up slightly more storage space.
+                    </p>
+                </div>
+
                 <div class="modal fade" tabindex="-1" role="dialog" id="dict-purge-modal">
                     <div class="modal-dialog modal-dialog-centered">
                         <div class="modal-content">