I had asked,
| >You mean LOGABSTRACT=all now logs `c'-flag pipe actions again?
Note the adverb "again" -- it used to, but it had stopped.
Philip responded,
| That's what makes LOGABSTRACT=all different from LOGABSTRACT=on. If
| the 'c' flag is all that keeps a recipe from being a delivering recipe,
| then LOGABSTACT=all will still log it if it succeeds. The bug in
| procmail version 3.11preX was that the LOGABSTRACT=all would log all
| successful recipes with the 'c' flag, regardless of whether that
| changed their delivering nature.
... and in several other releases since then, LOGABSTRACT=all logged nothing
except final delivery and `c' deliveries to folders; it didn't log `c'
deliveries to pipes nor `c' forwards to other address. That is why I used
the adverb "again."