Fixes crash when exporting after upgrading to v2.4.1-beta1 from v2.4.0

   The commudity UIDs across the database were invalidated.
   A new migration has been added to refresh them after a new import.
   This issue only affects beta1 users. Users who went directly from
   v2.4.0 to v2.4.1-beta2 are not affected

 - Properly refrsh the book name in the accounts activity

app/src/main/java/org/gnucash/android/db/DatabaseSchema.java

@@ -39,7 +39,7 @@ public class DatabaseSchema {
      * Version number of database containing accounts and transactions info.
      * With any change to the database schema, this number must increase
      */
-    public static final int DATABASE_VERSION = 16;
+    public static final int DATABASE_VERSION = 17;
 
     /**
      * Name of the database

app/src/main/java/org/gnucash/android/db/MigrationHelper.java

@@ -1653,4 +1653,26 @@ static int upgradeDbToVersion16(SQLiteDatabase db) {
 
         return dbVersion;
     }
+
+    /**
+     * Upgrades the database to version 17.
+     * This migration updates the foreign keys to the commodities in the splits table
+     * after a previous migration which overwrote the db table for commodities, rendering
+     * all foreign keys to commodity GUIDs invalid.
+     *
+     * @param db SQLite database to be upgraded
+     * @return New database version, 16 if migration succeeds, 15 otherwise
+     */
+    static int upgradeDbToVersion17(SQLiteDatabase db) {
+        Log.i(LOG_TAG, "Upgrading database to version 17");
+        int dbVersion = 16;
+
+        db.beginTransaction();
+        db.execSQL("UPDATE accounts SET commodity_uid = (SELECT uid FROM commodities WHERE mnemonic = accounts.currency_code)");
+        db.execSQL("UPDATE transactions SET commodity_uid = (SELECT uid FROM commodities WHERE commodities.mnemonic = transactions.currency_code)");
+
+        db.endTransaction();
+
+        return dbVersion + 1;
+    }
 }

app/src/main/java/org/gnucash/android/ui/account/AccountsActivity.java

@@ -37,6 +37,7 @@
 import android.support.v4.app.FragmentManager;
 import android.support.v4.app.FragmentPagerAdapter;
 import android.support.v4.view.ViewPager;
+import android.support.v7.app.ActionBar;
 import android.support.v7.app.AppCompatActivity;
 import android.support.v7.preference.PreferenceManager;
 import android.util.Log;
@@ -227,7 +228,6 @@ public void onCreate(Bundle savedInstanceState) {
 
         init();
 
-        getSupportActionBar().setSubtitle(BooksDbAdapter.getInstance().getActiveBookDisplayName());
         TabLayout tabLayout = (TabLayout) findViewById(R.id.tab_layout);
         tabLayout.addTab(tabLayout.newTab().setText(R.string.title_recent_accounts));
         tabLayout.addTab(tabLayout.newTab().setText(R.string.title_all_accounts));
@@ -269,6 +269,15 @@ public void onClick(View v) {
         });
 	}
 
+    @Override
+    protected void onResume() {
+        super.onResume();
+        ActionBar actionBar = getSupportActionBar();
+        if (actionBar != null) {
+            actionBar.setSubtitle(BooksDbAdapter.getInstance().getActiveBookDisplayName());
+        }
+    }
+
     @Override
     protected void onStart() {
         super.onStart();