[PATCH v3 00/22] Clean up refname checks and normalization

This patch series cleans up refname checks and normalization in a different way than v1 and v2. (Unnormalized refnames are those that have extra leading slashes or runs of repeated slashes between components, like "//refs/heads///master".)

As discussed on the mailing list [1], adding consistent support for unnormalized refnames everywhere was becoming a bottomless pit, so instead I am taking the opposite approach--only accept normalized refnames. Support for unnormalized refnames was broken anyway, so it shouldn't be missed.

There is only one command that is now meant to accept unnormalized refnames:

    $ git check-ref-format --normalize //refs/heads///master
    refs/heads/master
    $

This command can be used to normalize refnames for use elsewhere.

I have added a few internal checks that refnames have the correct format; more tests should still be added. But this patch series is getting quite long already, so I would like to submit it.

During the development of this patch series, I discovered that fetch_with_import() in remote-helper.c sometimes passes NULL to read_ref(), and thereby to resolve_ref(). The two commits labeled "remote: *" fix this in a naive way. But somebody more familiar with this code should check whether the fix is OK and more specifically whether this is a symptom of a bigger problem in the remote-helper code.

I should mention that this cleanup is preparation for my main goal: storing ref caches hierarchically. But there is still a lot of tangled up and seemingly redundant code in refs.c, so it might be a while before I get to the main project.

[1] http://permalink.gmane.org/gmane.comp.version-control.git/181268

Michael Haggerty (22):
  t1402: add some more tests
  git check-ref-format: add options --allow-onelevel and
    --refspec-pattern
  Change bad_ref_char() to return a boolean value
  Change check_ref_format() to take a flags argument
  Refactor check_refname_format()
  Do not allow ".lock" at the end of any refname component
  Make collapse_slashes() allocate memory for its result
  Inline function refname_format_print()
  Change check_refname_format() to reject unnormalized refnames
  resolve_ref(): explicitly fail if a symlink is not readable
  resolve_ref(): use prefixcmp()
  resolve_ref(): only follow a symlink that contains a valid,
    normalized refname
  resolve_ref(): turn buffer into a proper string as soon as possible
  resolve_ref(): extract a function get_packed_ref()
  resolve_ref(): do not follow incorrectly-formatted symbolic refs
  remote: use xstrdup() instead of strdup()
  remote: avoid passing NULL to read_ref()
  resolve_ref(): verify that the input refname has the right format
  resolve_ref(): emit warnings for improperly-formatted references
  resolve_ref(): also treat a too-long SHA1 as invalid
  resolve_ref(): expand documentation
  add_ref(): verify that the refname is formatted correctly

 Documentation/git-check-ref-format.txt |   53 ++++++--
 builtin/check-ref-format.c             |   61 ++++++---
 builtin/checkout.c                     |    2 +-
 builtin/fetch-pack.c                   |    2 +-
 builtin/receive-pack.c                 |    2 +-
 builtin/replace.c                      |    2 +-
 builtin/show-ref.c                     |    2 +-
 builtin/tag.c                          |    4 +-
 cache.h                                |   34 +++++-
 connect.c                              |    2 +-
 environment.c                          |    2 +-
 fast-import.c                          |    7 +-
 git_remote_helpers/git/git.py          |    2 +-
 notes-merge.c                          |    5 +-
 pack-refs.c                            |    2 +-
 refs.c                                 |  222 +++++++++++++++++++-------------
 refs.h                                 |   21 +++-
 remote.c                               |   55 ++------
 sha1_name.c                            |    4 +-
 t/t1402-check-ref-format.sh            |  120 +++++++++++++++--
 transport-helper.c                     |   10 +-
 transport.c                            |   16 +--
 walker.c                               |    2 +-
 23 files changed, 408 insertions(+), 224 deletions(-)