ResolvePrincipal returns SPPrincipalInfo with PrincipalId == -1

Question

When/why does SPUtility.ResolvePrincipal return a non-null SPPrincipalInfo with a PrincipalId of -1 ? I can manually assign rights to the user through the web interface. The user resides in an active directory. If I request a non existing user null is being returned as expected. The same logic works for a lot of other users.

SPPrincipalInfo principalInfo = SPUtility.ResolvePrincipal(currentWeb, objectPrincipal, SPPrincipalType.All, SPPrincipalSource.All, null, false);
if (principalInfo == null)
{
  result[i][j] = "Can not determine principalInfo for name: " + objectPrincipal;
  continue;
}
if (principalInfo.PrincipalId <= 0)
{
  result[i][j] = "Got invalid PrincipalId: " + principalInfo.PrincipalId + " in principalInfo for name: " + objectPrincipal;
  continue;
}

My log output:

Setting rights failed for user: DOMAIN\usr1 error: Got invalid PrincipalId: -1 in principalInfo for name: DOMAIN\usr1

Any ideas?

Answer 1

When null is returned the user does not exist, when PrincipalId -1 is returned I have now used the EnsureUser method to make the existing user known to the sharepoint system.