None of the devices I own have ifIndexes that begin with 0 (arista, HP, brocade/foundry). Mainly noticed this with my Brocade devices as the vlan to port mappings were off.
I've attached a patch that uses the $vlan_ifindex_map someone setup but didn't complete implementation. This patch looks in the lowest index of $vlan_ifindex_map for the dot1dBasePortIfIndex to determine the lowest possible ifIndex and adds that to the index used to assign vlans found to ports as an offset.
I recommend not blindly accepting this patch and testing it in your own environment to ensure it doesn't break your stuff.
Major