Since 243b6c3b8fd3144450c477d99f01e31e7c3ebc0f (21-08-19), this bug can't be reproduced.

In `pysqlite_do_all_statements()`, 243b6c3 resets statements like this:

    sqlite3_stmt *stmt = NULL;
    while ((stmt = sqlite3_next_stmt(self->db, stmt))) {
        if (sqlite3_stmt_busy(stmt)) {
            (void)sqlite3_reset(stmt);
        }
    }
    
But the `pysqlite_Statement.in_use` flag is not reset.
In `_pysqlite_query_execute()` function, if `pysqlite_Statement.in_use` flag is 1, it creates a new `pysqlite_Statement` instance. So this line will use a new statement:

    gen = conn.execute("SELECT c FROM t WHERE ?", (1,))

The duplicate row is from `pysqlite_Cursor.next_row` before 3df0fc89bc2714f5ef03e36a926bc795dcd5e05a (21-08-25).

A digressive suggestion is whether it can be changed like this, and add a check for resetting statement. So that statements are not allowed to be reset by other Cursors, which may improve code robust:

    typedef struct
    {
        ...
-       int in_use;
+       pysqlite_Cursor *in_use; // points to the attached cursor
        ...
    } pysqlite_Statement;