It sets up the normal git environment variables and a few helper
functions (currently just "die()"), and returns ok if it all looks like
a git archive. So use it something like
. git-sh-setup-script || die "Not a git archive"
to make the rest of the git scripts more careful and readable.
We codify the following different heads (in addition to the main "HEAD",
which points to the current branch, of course):
- FETCH_HEAD
Populated by "git fetch"
- ORIG_HEAD
The old HEAD before a "git pull/resolve" (successful or not)
- LAST_MERGE
The HEAD we're currently merging in "git pull/resolve"
- MERGE_HEAD
The previous head of a unresolved "git pull", which gets committed by
a "git commit" after manually resolving the result
We used to have "MERGE_HEAD" be populated directly by the fetch, and we
removed ORIG_HEAD and LAST_MERGE too aggressively.
