[Ur] Almost 100% bug in request() algorithm

Sun Jun 15 17:10:23 EDT 2014

Hi! I've found a bug while debugging my FFI code!

Look at the request() from request.c. It contains the following pattern:

    ...
    }
    else if (fk == FATAL) {
      log_error(logger_data, "Fatal error: %s\n", uw_error_message(ctx));

      if (uw_get_app(ctx)->on_error && !had_error) {
        had_error = 1;
        strcpy(errmsg, uw_error_message(ctx));
      } else {
        uw_reset_keep_error_message(ctx);
        on_failure(ctx);
        uw_write_header(ctx, "Content-type: text/html\r\n");
        uw_write(ctx, "<html><head><title>Fatal Error</title></head><body>");
        uw_write(ctx, "Fatal error: ");
        uw_write(ctx, uw_error_message(ctx));
        uw_write(ctx, "\n</body></html>");

        try_rollback(ctx, 0, logger_data, log_error);

        return FAILED;
      }
    } else {
    ...

Note, that try_rollback() is executed _after_
uw_reset_keep_error_message(). It is an error because reset will
assign ctx->used_transactionals to 0 and prevent FFI cleanup handlers
from working! Let me suggest calling try_rollback() before reset.
Please, check!

Regards,
Sergey

PS
I didn't update the compiler up to the latest version yet.