[0/3] fast-export, fast-import: let tags specify a different refname

Message

Luke Shumaker April 22, 2021, 1:06 a.m. UTC

From: Luke Shumaker <[e-mail]>

After receiving positive feedback on the RFC, here's the polished-up
v1.

This patchset adds an optional "refname" sub-command to fast-import's "tag"
top-level-command; the stream

    tag foo
    refname refs/tags/bar
    ...

will create a tag at "refs/tags/bar" that says "tag foo" internally.
If there is no "refname" line, it will continue with the existing
behavior of using "refs/tags/<tagname>" as the refname.

This makes it now-possible for fast-export/fast-import to represent
tags for which the internal tagname and the refname disagree.  It also
adds support for tags with refnames that do not begin with
"refs/tags/".  I discuss the motivation for supporting this in the
commit message of the 3rd patch.

Changes from the RFC:

 - I've flipped it around; the existing `tag` line now specifices the
   tagname, and the added `refname` line now specifies the refname
   (rather than having the `tag` line specify the suffix of the
   refname, and the added `name` line specify the tagname).  This
   allows for tags whose refnames to not begin with "refs/tags/".
 - I've added prose documentation, rather than just updating the BNF.
   (The wording is based on what Junio suggested on the RFC.)
 - I added tests.
 - After responding to feedback, I ended up with just enough "moving
   and renaming things" noise that in the single commit that for v1 I
   split that out in to a econd commit.
 - While implementing the tests, I discovered a pre-existing bug with
   nested tags, so I added a separate third commit to fix that.

This passes all of the GitHub Actions CI checks, and passes all but
one of the Travis-CI checks; the failing Travis-CI check seems to be
an unrelated 404 from `apt-get`.
https://github.com/LukeShu/git/runs/2405478827

[1]: https://lore.kernel.org/git/[e-mail]/

Luke Shumaker (3):
  fast-export, fast-import: make stylistic changes
  fast-export: fix bug with nested tags
  fast-export, fast-import: let tags specify a different refname

 Documentation/git-fast-import.txt | 22 +++++++++------
 builtin/fast-export.c             | 47 ++++++++++++++++++++++++++-----
 builtin/fast-import.c             | 47 +++++++++++++++++++------------
 t/t9350-fast-export.sh            | 20 ++++++++++---
 4 files changed, 98 insertions(+), 38 deletions(-)