Downloaded file already pre-tagged in Mavericks?

[maddux530]

I downloaded StatPlus:mac LE (a statistics/data analysis tool) tonight. It's an old, outdated program, but I need it for Excel 2011. After unzipping the file, I noticed the .dmg file and the ReadMe file were both already tagged Orange in Finder.

😕

I've never used the tagging system in Mavericks. I even had to Google what the orange dot next to the file was since I hadn't seen it before. How could a file come pre-tagged? It's especially peculiar because I think this particular software was last updated in 2010, long before Mavericks and long before tagging existed.

What the heck is going on? Thanks for your input.

 

[chown33]

A dmg preserves whatever metadata and attributes are already attached to the file. This is normal, because a dmg is a disk-image, so it intentionally emulates the behavior of a disk.

Before Mavericks, a file's assigned color was stored in the com.apple.FinderInfo xattr, a.k.a. the HFS/HFS+ FinderInfo structure. If a file has only a single tag in Mavericks, that's still where it's stored. Additional tags are stored in additional xattrs, and they too will be preserved should their file be copied to a dmg.

The FinderInfo is much older than even Mac OS X. As soon as color labels were introduced in Finder, coincident with the release of Color QuickDraw, a spot was reserved for it in the HFS metadata. You can still get .img files from that time, or .sit files (StuffIt), or HFS floppies, and they all can have the color label on any file or folder.

You can look up the technical details of exactly where this exists in HFS/HFS+ metadata, or how FinderInfo is mapped to the com.apple.FinderInfo xattr, or xattrs in general.

Short answer: it goes along with the file, and has done so since before OS X.