Fix handle leak

Author: cincuranet

src/Microsoft.Data.Sqlite.Core/SqliteConnectionInternal.cs

@@ -97,46 +97,54 @@ public SqliteConnectionInternal(SqliteConnectionStringBuilder connectionOptions,
                 ? connectionOptions.Vfs
                 : null;
             var rc = sqlite3_open_v2(filename, out _db, flags, vfs: vfs);
-            SqliteException.ThrowExceptionForRC(rc, _db);
-
-            if (connectionOptions.Password.Length != 0)
+            try
             {
-                if (SQLitePCLExtensions.EncryptionSupported(out var libraryName) == false)
+                SqliteException.ThrowExceptionForRC(rc, _db);
+
+                if (connectionOptions.Password.Length != 0)
                 {
-                    throw new InvalidOperationException(Resources.EncryptionNotSupported(libraryName));
+                    if (SQLitePCLExtensions.EncryptionSupported(out var libraryName) == false)
+                    {
+                        throw new InvalidOperationException(Resources.EncryptionNotSupported(libraryName));
+                    }
+
+                    // NB: SQLite doesn't support parameters in PRAGMA statements, so we escape the value using the
+                    //     quote function before concatenating.
+                    var quotedPassword = ExecuteScalar(
+                        "SELECT quote($password);",
+                        connectionOptions.Password,
+                        connectionOptions.DefaultTimeout);
+                    ExecuteNonQuery(
+                        "PRAGMA key = " + quotedPassword + ";",
+                        connectionOptions.DefaultTimeout);
+
+                    if (SQLitePCLExtensions.EncryptionSupported() != false)
+                    {
+                        // NB: Forces decryption. Throws when the key is incorrect.
+                        ExecuteNonQuery(
+                            "SELECT COUNT(*) FROM sqlite_master;",
+                            connectionOptions.DefaultTimeout);
+                    }
                 }
 
-                // NB: SQLite doesn't support parameters in PRAGMA statements, so we escape the value using the
-                //     quote function before concatenating.
-                var quotedPassword = ExecuteScalar(
-                    "SELECT quote($password);",
-                    connectionOptions.Password,
-                    connectionOptions.DefaultTimeout);
-                ExecuteNonQuery(
-                    "PRAGMA key = " + quotedPassword + ";",
-                    connectionOptions.DefaultTimeout);
-
-                if (SQLitePCLExtensions.EncryptionSupported() != false)
+                if (connectionOptions.ForeignKeys.HasValue)
                 {
-                    // NB: Forces decryption. Throws when the key is incorrect.
                     ExecuteNonQuery(
-                        "SELECT COUNT(*) FROM sqlite_master;",
+                        "PRAGMA foreign_keys = " + (connectionOptions.ForeignKeys.Value ? "1" : "0") + ";",
                         connectionOptions.DefaultTimeout);
                 }
-            }
 
-            if (connectionOptions.ForeignKeys.HasValue)
-            {
-                ExecuteNonQuery(
-                    "PRAGMA foreign_keys = " + (connectionOptions.ForeignKeys.Value ? "1" : "0") + ";",
-                    connectionOptions.DefaultTimeout);
+                if (connectionOptions.RecursiveTriggers)
+                {
+                    ExecuteNonQuery(
+                        "PRAGMA recursive_triggers = 1;",
+                        connectionOptions.DefaultTimeout);
+                }
             }
-
-            if (connectionOptions.RecursiveTriggers)
+            catch
             {
-                ExecuteNonQuery(
-                    "PRAGMA recursive_triggers = 1;",
-                    connectionOptions.DefaultTimeout);
+                _db.Dispose();
+                throw;
             }
 
             _pool = pool;

test/Microsoft.Data.Sqlite.Tests/SqliteConnectionTest.cs

@@ -1284,4 +1284,46 @@ public void GetSchema_ReservedWords_works()
             dataTable.Rows.Cast<DataRow>(),
             r => (string)r[DbMetaDataColumnNames.ReservedWord] == "SELECT");
     }
+
+    [Fact]
+    public void Open_releases_handle_when_constructor_fails()
+    {
+        var dbPath = Path.GetTempFileName();
+
+        // Create a file with invalid database content.
+        File.WriteAllText(dbPath, "this is not a database file but should still open with sqlite3_open_v2");
+
+        // Use password to trigger the encryption path in SqliteConnectionInternal ctor.
+        // This should fail during password verification when trying to decrypt the invalid file.
+        var connectionString = $"Data Source={dbPath};Password=test;Mode=ReadOnly;Pooling=False";
+
+        using (var connection = new SqliteConnection(connectionString))
+        {
+
+#if E_SQLITE3 || WINSQLITE3
+            var ex = Assert.Throws<InvalidOperationException>(connection.Open);
+            Assert.Equal(Resources.EncryptionNotSupported(GetNativeLibraryName()), ex.Message);
+            Assert.Equal(ConnectionState.Closed, connection.State);
+#elif E_SQLCIPHER || E_SQLITE3MC || SQLCIPHER
+            var ex = Assert.Throws<SqliteException>(connection.Open);
+            Assert.Equal(SQLITE_NOTADB, ex.SqliteErrorCode);
+            Assert.Equal(ConnectionState.Closed, connection.State);
+#else
+            // No code path in SqliteConnectionInternal ctor that would trigger exception
+            // and leave the handle open.
+#endif
+        }
+
+        if (Environment.OSVersion.Platform == PlatformID.Win32NT)
+        {
+            // On Windows, this will fail if there's a file handle leak.
+            File.Delete(dbPath);
+        }
+        else
+        {
+            // On Unix-like systems, we can still delete the file but cannot 
+            // reliably detect handle leaks this way.
+            File.Delete(dbPath);
+        }
+    }
 }