Re: Figured out how to get Mozilla into git

Rogan Dawes [off-list ref] writes:

Here's an idea. How about separating trees and commits from the actual
blobs (e.g. in separate packs)?

If I remember my numbers correctly, trees for any project with a
size that matters contribute nonnegligible amount of the total
pack weight.  Perhaps 10-25%.

In this way, the user has a history that will show all of the commit
messages, and would be able to see _which_ files have changed over
time e.g. gitk would still work - except for the actual file level
diff, "git log" should also still work, etc

I suspect it would make a very unpleasant system to use.
Sometimes "git diff -p" would show diffs, and other times it
mysteriously complain saying that it lacks necessary blobs to do
its job.  You cannot even run fsck and tell from its output
which missing objects are OK (because you chose to create such a
sparse repository) and which are real corruption.

A shallow clone with explicit cauterization in grafts file at
least would not have that problem. Although the user will still
not see the exact same result as what would happen in a full
repository, at least we can say "your git log ends at that
commit because your copy of the history does not go back beyond
that" and the user would understand.