httpcache.Syncer interface: Fetch() (bool, error) — satisfied by both
*httpcache.Cacher and *gitshallow.Repo (new Fetch method + LightGC field).
httpcache.Cacher.Fetch now errors on zero-length 200 response instead of
clobbering the existing file with empty content.
Sources.Fetch/Init drop the lightGC param (baked into Repo.LightGC).
Sources.syncs []httpcache.Syncer replaces the separate git/httpInbound/
httpOutbound fields — Fetch iterates syncs uniformly, no more switch.
Sources itself satisfies httpcache.Syncer.
httpcache.Cacher gains:
- Username/Password: Basic Auth, stripped before following redirects
- MaxAge: skip HTTP if local file mtime is within this duration
- MinInterval: skip HTTP if last Fetch attempt was within this duration
- Transform: post-process response body (e.g. extract .mmdb from tar.gz)
geoip.Downloader now builds an httpcache.Cacher via NewCacher(), removing
its own HTTP client. ExtractMMDB is now exported for use as a Transform.
check-ip-blacklist renamed to check-ip; adds -city-db / -asn-db flags
for GeoLite2 lookup (country, city, subdivision, ASN) printed after each
blocklist result.