Undefined version comparisions
While writing the version parsing for stem I noticed that the version spec [1] doesn't define how to compare empty tags and patch levels. For instance, if "1.2.3.4-myTag" is a greater or lower version than "1.2.3-myTag".
My suggestion would be to add a note that an undefined patch is zero and undefined tag equates to the empty string. Ie...
"1.2.3-myTag" == "1.2.3.0-myTag" "1.2.3.4" == "1.2.3.4-"
Cheers! -Damian
[1] https://gitweb.torproject.org/torspec.git/blob/HEAD:/version-spec.txt