I was talking to a colleague about one rather unexpected/undesired behavior of some package we use. Although there is an easy fix (or at least workaround) on our end without any apparent side effect, he strongly suggested extending the relevant code by hard patching it and posting the patch upstream, hopefully to be accepted at some point in the future. In fact we maintain patches against specific versions of several packages that are applied automatically on each new build. The main argument is that this is the right thing to do, as opposed to an "ugly" workaround or a fragile monkey patch. On the other hand, I favor practicality over purity and my general rule of thumb is that "no patch" > "monkey patch" > "hard patch", at least for anything other than a (critical) bug fix.

So I'm wondering if there is a consensus on when it's better to (hard) patch, monkey patch or just try to work around a third party package that doesn't do exactly what one would like. Does it have mainly to do with the reason for the patch (e.g. fixing a bug, modifying behavior, adding missing feature), the given package (size, complexity, maturity, developer responsiveness), something else or there are no general rules and one should decide on a case-by-case basis ?