--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/com/five_ten_sg/connectbot/util/RobustSQLiteOpenHelper.java	Thu May 22 10:41:19 2014 -0700
@@ -0,0 +1,135 @@
+/*
+ * ConnectBot: simple, powerful, open-source SSH client for Android
+ * Copyright 2007 Kenny Root, Jeffrey Sharkey
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.five_ten_sg.connectbot.util;
+
+import java.util.LinkedList;
+import java.util.List;
+
+import android.content.Context;
+import android.database.Cursor;
+import android.database.sqlite.SQLiteDatabase;
+import android.database.sqlite.SQLiteDatabase.CursorFactory;
+import android.database.sqlite.SQLiteException;
+import android.database.sqlite.SQLiteOpenHelper;
+
+/**
+ * @author Kenny Root
+ *
+ */
+public abstract class RobustSQLiteOpenHelper extends SQLiteOpenHelper {
+    private static List<String> mTableNames = new LinkedList<String>();
+    private static List<String> mIndexNames = new LinkedList<String>();
+
+    public RobustSQLiteOpenHelper(Context context, String name,
+                                  CursorFactory factory, int version) {
+        super(context, name, factory, version);
+    }
+
+    protected static void addTableName(String tableName) {
+        mTableNames.add(tableName);
+    }
+
+    protected static void addIndexName(String indexName) {
+        mIndexNames.add(indexName);
+    }
+
+    @Override
+    public void onCreate(SQLiteDatabase db) {
+        dropAllTables(db);
+    }
+
+    @Override
+    public final void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
+        try {
+            onRobustUpgrade(db, oldVersion, newVersion);
+        }
+        catch (SQLiteException e) {
+            // The database has entered an unknown state. Try to recover.
+            try {
+                regenerateTables(db);
+            }
+            catch (SQLiteException e2) {
+                dropAndCreateTables(db);
+            }
+        }
+    }
+
+    public abstract void onRobustUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) throws SQLiteException;
+
+    private void regenerateTables(SQLiteDatabase db) {
+        dropAllTablesWithPrefix(db, "OLD_");
+
+        for (String tableName : mTableNames)
+            db.execSQL("ALTER TABLE " + tableName + " RENAME TO OLD_"
+                       + tableName);
+
+        onCreate(db);
+
+        for (String tableName : mTableNames)
+            repopulateTable(db, tableName);
+
+        dropAllTablesWithPrefix(db, "OLD_");
+    }
+
+    private void repopulateTable(SQLiteDatabase db, String tableName) {
+        String columns = getTableColumnNames(db, tableName);
+        StringBuilder sb = new StringBuilder();
+        sb.append("INSERT INTO ")
+        .append(tableName)
+        .append(" (")
+        .append(columns)
+        .append(") SELECT ")
+        .append(columns)
+        .append(" FROM OLD_")
+        .append(tableName);
+        String sql = sb.toString();
+        db.execSQL(sql);
+    }
+
+    private String getTableColumnNames(SQLiteDatabase db, String tableName) {
+        StringBuilder sb = new StringBuilder();
+        Cursor fields = db.rawQuery("PRAGMA table_info(" + tableName + ")", null);
+
+        while (fields.moveToNext()) {
+            if (!fields.isFirst())
+                sb.append(", ");
+
+            sb.append(fields.getString(1));
+        }
+
+        fields.close();
+        return sb.toString();
+    }
+
+    private void dropAndCreateTables(SQLiteDatabase db) {
+        dropAllTables(db);
+        onCreate(db);
+    }
+
+    private void dropAllTablesWithPrefix(SQLiteDatabase db, String prefix) {
+        for (String indexName : mIndexNames)
+            db.execSQL("DROP INDEX IF EXISTS " + prefix + indexName);
+
+        for (String tableName : mTableNames)
+            db.execSQL("DROP TABLE IF EXISTS " + prefix + tableName);
+    }
+
+    private void dropAllTables(SQLiteDatabase db) {
+        dropAllTablesWithPrefix(db, "");
+    }
+}