added workaround to comply with existing saved preference where the options array included more values than the new array has in newer versions, so this ListPreference extension checks for bounds to prevent IOBException and defaults to the system value

Author: mzorz

Simplenote/src/main/java/com/automattic/simplenote/PreferencesFragment.java

@@ -215,9 +215,6 @@ public boolean onPreferenceChange(Preference preference, Object newValue) {
             }
 
             private void updateTheme(Activity activity, int index) {
-                CharSequence[] entries = themePreference.getEntries();
-                themePreference.setSummary(entries[index]);
-
                 AnalyticsTracker.track(
                         AnalyticsTracker.Stat.SETTINGS_THEME_UPDATED,
                         AnalyticsTracker.CATEGORY_USER,

Simplenote/src/main/java/com/automattic/simplenote/utils/SafeThemeListPreference.kt

@@ -0,0 +1,42 @@
+package com.automattic.simplenote.utils
+
+import android.content.Context
+import android.util.AttributeSet
+import androidx.preference.ListPreference
+
+/**
+ * Custom ListPreference that handles invalid index values to prevent ArrayIndexOutOfBoundsException.
+ * This preference safely handles cases where the stored value doesn't match any of the available entries.
+ */
+class SafeThemeListPreference @JvmOverloads constructor(
+    context: Context,
+    attrs: AttributeSet? = null,
+    defStyleAttr: Int = androidx.preference.R.attr.preferenceStyle,
+    defStyleRes: Int = 0
+) : ListPreference(context, attrs, defStyleAttr, defStyleRes) {
+
+    override fun getSummary(): CharSequence? {
+        val value = getValue()
+        val entries = getEntries()
+        
+        if (entries == null || entries.isEmpty()) {
+            return super.getSummary()
+        }
+        
+        val index = findIndexOfValue(value)
+        
+        // If index is invalid (out of bounds or -1), fallback to default value
+        return if (index >= 0 && index < entries.size) {
+            entries[index]
+        } else {
+            // Get the default value (2 = theme_system) and return its entry
+            val defaultIndex = findIndexOfValue("2")
+            if (defaultIndex >= 0 && defaultIndex < entries.size) {
+                entries[defaultIndex]
+            } else {
+                // Ultimate fallback - return the first entry
+                entries[0]
+            }
+        }
+    }
+}

Simplenote/src/main/res/xml/preferences.xml

@@ -41,15 +41,14 @@
         android:key="pref_key_appearance_preferences"
         android:title="@string/appearance">
 
-        <ListPreference
+        <com.automattic.simplenote.utils.SafeThemeListPreference
             android:key="pref_key_theme"
             android:defaultValue="2"
             android:entries="@array/array_theme_names"
             android:entryValues="@array/array_theme_values"
-            android:summary="%s"
             android:title="@string/theme"
             tools:summary="@string/theme_system">
-        </ListPreference>
+        </com.automattic.simplenote.utils.SafeThemeListPreference>
 
         <Preference
             android:key="pref_key_style"