Add a finalizer and prevent double dispose of SQLiteDatabaseConnection.

Author: bordoley

SQLitePCL.pretty.tests/DatabaseConnectionTests.cs

@@ -26,6 +26,16 @@ namespace SQLitePCL.pretty.tests
     [TestFixture]
     public class SQLiteDatabaseConnectionTests
     {
+        [Test]
+        public void TestFinalize()
+        {
+            // There is no way to assert, so this test is primarily for code coverage.
+            var db = SQLite3.Open(":memory:");
+            var stmt = db.PrepareStatement("SELECT 1;");
+
+            GC.Collect();
+        }
+
         [Test]
         public void TestDispose()
         {

SQLitePCL.pretty/DatabaseConnection.cs

@@ -1126,6 +1126,14 @@ public void RemoveCommitHook()
         /// <inheritdoc/>
         public void Dispose()
         {
+            Dispose(true);
+            GC.SuppressFinalize(this);
+        }
+
+        private void Dispose(bool disposing)
+        {
+            if (disposed) { return; }
+
             this.Disposing(this, null);
 
             disposed = true;
@@ -1134,6 +1142,12 @@ public void Dispose()
             raw.sqlite3_close(db);
         }
 
+        /// <inheritdoc/>
+        ~SQLiteDatabaseConnection()
+        {
+            Dispose(false);
+        }
+
         private sealed class CtxState<T>
         {
             private readonly T value;