JENKINS-2673, JENKINS-1406 Fix inappropriate cron warnings

[RichardBradley]

As the other commenters on https://issues.jenkins-ci.org/browse/JENKINS-2673 found, I was surprised to see a slightly confusing warning from Jenkins when I set my update schedule to "* * * * *".

This patch should:

• Not issue the minutes / hours warning in the "* * * * *" case, as it seems inappropriate
• Improve the warning in the cases where it is appropriate (see JENKINS-1406 for motivating examples)

I wasn't able to run the unit tests: would it be possible for whoever picks this up to run the tests before merging?

Thanks,

Rich

[kutzi]

I think this needs a unit test. I find this method quite hard to understand - mainly already because of the existing code and not your changes. But anyway a unit test would greatly help to document which pattern(s?) should be warned about and which not.

[daniel-beck]

This PR cannot be merged and the author did not respond to a request for a unit test in over a year, so I'm closing this. It could still be reconsidered as a new PR that can be merged and maybe has a test.

(IMO the existence of the warning is appropriate, as polling every minute is often just not a good idea -- the warning just needs to be rephrased to mention that the suggested alternative polls once per hour.)