Confusion over handing of pnadd

[dlakaplan]

From what I can see, the way PINT handles -pnadd flags is:

• construct a phase array from the sum of -phase and -pnadd flags
• use that to populate the delta_pulse_number column
• add those values on a toa-by-toa basis to the residuals

However, we got a comment that this is not how TEMPO2 does it. The comment there is that:

the pulse number “-pn” is reset to 0 where “-pnadd” is provided. The “-pnadd” value gets added to the “-pn” values of all subsequent ToAs.
PINT does neither of these things. It does not set -pn to 0, and it only adds -pnadd to each TOA separately.

Can somebody clarify how TEMPO2 handles these things? Is the PINT behavior actually intentionally different? I don't see tests for it.