Ensure up-to-date copyright years

[lkuper]

People don't consistently update the year in the copyright block when they edit a file. Could we either (a) just globally update them all to the latest year when the year changes (as suggested by @thestinger on IRC), or (b) if we really have to have per-file copyright granularity, have tidy check that the copyright year matches the last-modified date of the file?

[thestinger]

cc @brson - probably just have to ping Mozilla's legal department and see if we could handle the copyright year on a project basis rather than a file basis

As far as I know, we only have the per-file headers to avoid mistakes if someone extracts a portion of the project, and to keep it clear which files are under different licenses.

[brson]

I've been given advice that the entire copyright line, including the date is legally all but worthless, so it basically doesn't matter whether we keep them up to date or not. It was suggested that we continue to do it on a best-effort basis and not sweat it, though I guess that's not too satisfying since putting any effort into something useless is kinda silly.

[brson]

Having them be inconsistent also just rubs one the wrong way too. If anyone feel strongly we should add some automation here we can still consider it.

[ahmedcharles]

Just curious, where's the check code that runs during the build to verify line lengths? That's probably easy to update to check the header of each file?

[brson]

@ahmedcharles src/etc/tidy.py and src/etc/licenseck.py

[frewsxcv]

/cc @gerv since he was consulted in #21481

IANAL, but realistically I wouldn't think there's much of a difference if the year in the header is off by a couple years.

[gerv]

The policy I recommend is:

• Don't bother to update them
• If someone does update them in a patch, ignore it (i.e. accept the patch without comment)

The actual copyright status of the file is unaffected by what it says at the top, so people for whom it's actually important when the copyright expires (i.e. no-one) will have to do more research in any case.

[frewsxcv]

@gerv Sounds very sane in my opinion. Given that response, this can be closed?

[lkuper]

Yeah, since filing this bug over a year ago I came to realize (from working on another project) that the dates in the files really don't matter. I also think it can be closed.

[alexcrichton]

Ok, thanks for the info @gerv!