Error getting signer certificates from PKCS7

[Massimiliano Ziccardi]

Hi all.
The attached file is the PEM encoding of a file structured this way:

SIGNATURE 1
   COUNTER SIGNATURE 1 of SIGNATURE 1
       COUNTER SIGNATURE 1 of COUNTER SIGNATURE 1 of SIGNATURE 1

each signer has a different signature certificate (3 certificate total).

Why the
    STACK_OF(X509) *pSigners = PKCS7_get0_signers(m_pP7, NULL, 0);

retruns only 1 certificate?

Thanks in advance,
Massimiliano Ziccardi

test.pem
Description: Binary data