Spotlight: Fix timestamps and add additional attributes

[NJRoadfan]

Upstream patch from Samba. Fixes: #2258

[augmentcode]

🤖 Augment PR Summary

Summary: Pulls in an upstream Samba fix for Spotlight metadata encoding to address incorrect timestamps (Fixes: #2258).

Changes:

• Adds support for additional metadata keys: _kMDItemFileName, kMDItemLogicalSize, and kMDItemLastUsedDate.
• Corrects the Spotlight epoch definition (2001-01-01 UTC) and updates date marshalling/unmarshalling to use an IEEE-754 double with microsecond precision.

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[augmentcode]

Review completed. 2 suggestions posted.

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[rdmark]

great patch, I'm pleased to see the spotlight code getting some long-overdue love

I was thinking about attribution since this is ported from Samba; seems like portions were authored by Ralph in samba-team/samba@5d4ecea and samba-team/samba@5d4ecea

the convert_timespec_to_timeval structure was authored by Jeremy Allison in 2007 samba-team/samba@4952fe3 but maybe it can be considered boilerplate / trivial?

[NJRoadfan]

Some (all?) platforms have a macro called TIMESPEC_TO_TIMEVAL in <sys/time.h>.

[rdmark]

heads-up that this patch caused a breakage: when spotlight is active it's not possible to edit a file in-place on an AFP volume, e.g. with TextEdit on macOS

TextEdit warns that "another application has modified the file" and prevents you from saving, probably due to the timestamp changing in a way that it doesn't expect

[NJRoadfan]

Steps to reproduce?

TextEdit (at least in Catalina) is not producing the same issue on my end with Spotlight enabled. I would be curious to see if this can be reproduced on a Samba share with Spotlight enabled as it uses the same method of updating the "Last Opened" time on the server side.

I am opening a text file, making changes, then saving in place. I do get a note from TextEdit the first time I save that the file system doesn't support storing revisions, but other then that it works fine.

[NJRoadfan]

Give #2896 a try. I noticed a regression where mtime was being set to -1 on the filesystem. This is likely causing problems elsewhere.