In response to my recent patches attempting to fix pacman's repetitive
output with --noprogressbar, agregory kindly pointed out an obvious
error I missed and suggested that I tackle the problem by making alpm's
download callback function return normalized output[1].
[1]: https://wiki.archlinux
From: Ivy Foster
When curl calls alpm's dlcb, alpm calls the frontend's cb with the
following (dlsize, totalsize) arguments:
0, -1: initialize
0, 0: no change since last call
x {x>0, x0}: data downloaded, total size known
x {x>0}, x: download finished
If total size is not known, do not call fro
