SQLCipherStatement.close() never closes its Cursor, leaking a CursorWindow per Room query #97

SQLCipherStatement.close() sets closed = true and never closes the Cursor that step() created. Only reset() closes it:

public void reset() {
    if (cursor != null) {
        cursor.close();
        cursor = null;
    }
    stepped = false;
}

public void close() {
    closed = true;
}

Room 3 (androidx.room3 3.0.3) prepares, steps and closes a statement per query, and it never calls reset() before close(). So every query leaves a CursorWindow for the finalizer to free.

Versions: sqlcipher-android 4.18.0 through 4.19.1 and the current default branch, with Room 3.0.3 and SQLCipherDriver.

Measured: we ran 20,000 point reads of one 20 KB row through Room with SQLCipherDriver, on Android emulators, with no manual GC.

The framework's AndroidSQLiteDriver showed 24 KB over the same reads.

Workaround: we wrap the driver so that each statement's close() calls reset() first:

private class CursorClosingStatement(private val delegate: SQLiteStatement) : SQLiteStatement by delegate {
    override fun close() {
        delegate.reset()
        delegate.close()
    }
}

Suggested fix: in close(), close the cursor if it is open, as reset() does, before setting closed = true.