Follow-up from "Fix for -p -nc Bug": We need more tests for this
From 'man wget':
When running Wget with -r or -p, but without -N, -nd, or -nc, re-downloading a file will result in the new copy simply overwriting the old. Adding -nc will prevent this behavior, instead causing the original version to be preserved and any newer copies on the server to be ignored. When running Wget with -N, with or without -r or -p, the decision as to whether or not to download a newer copy of a file depends on the local and remote timestamp and size of the file. -nc may not be specified at the same time as -N.
So maybe we even need more tests (all combinations of -N, -r and -nc). At least we should follow the documented wget1.x behavior for backwards compatibility.