Linus Torvalds [off-list ref] writes:
Considering that TRANSPORT_SUMMARY and TRANSPORT_SUMMARY_WIDTH are both used in exactly one place each, I'd suggest getting rid of that crazy macro, and just expanding it in those places to avoid these kinds of crazy "hiding variables inside complex defines thning". And maybe just deciding to hardcode TRANSPORT_SUMMARY_WIDTH to 17 (which was it's original default value and presumably is what the test is effectively hardcoded for too), and avoiding that complexity entirely.
For all fairness, when the WIDTH thing was introduced, there were two places that needed reference it at f1863d0d16 ("refactor duplicated code in builtin-send-pack.c and transport.c", 2010-02-16). But that is no longer the case, and it makes sense to hardcode it as 17 (or something derived from a symbolic constant that gives the new "default to default"). What TRANSPORT_SUMMARY() does is even more crazy and it really shouldn't be exposed as a public interface. Let's move it to its single calling place.