Change checkout.c to check if a ref exists instead of checking if a loose ref
file exists when deciding if to delete an orphaned log file. Otherwise, if a
ref only exists as a packed ref without a corresponding loose ref for the
currently checked out branch, we risk that the reflog will be deleted when we
switch to a different branch.

Update the reflog tests to check for this bug.

The following reproduces the bug:
$ git init-db
$ git config core.logallrefupdates true
$ git commit -m Initial --allow-empty
    [master (root-commit) bb11abe] Initial
$ git reflog master
    [8561dcb master@{0}: commit (initial): Initial]
$ find .git/{refs,logs} -type f | grep master
    [.git/refs/heads/master]
    [.git/logs/refs/heads/master]
$ git branch foo
$ git pack-refs --all
$ find .git/{refs,logs} -type f | grep master
    [.git/logs/refs/heads/master]
$ git checkout foo
$ find .git/{refs,logs} -type f | grep master
    ... reflog file is missing ...
$ git reflog master
    ... nothing ...

Signed-off-by: Ronnie Sahlberg <sahlberg@google.com>
Acked-by: Michael Haggerty <mhagger@alum.mit.edu>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

Add two new functions, reflog_exists and delete_reflog, to hide the internal
reflog implementation (that they are files under .git/logs/...) from callers.
Update checkout.c to use these functions in update_refs_for_switch instead of
building pathnames and calling out to file access functions. Update reflog.c
to use these to check if the reflog exists. Now there are still many places
in reflog.c where we are still leaking the reflog storage implementation but
this at least reduces the number of such dependencies by one. Finally
change two places in refs.c itself to use the new function to check if a ref
exists or not isntead of build-path-and-stat(). Now, this is strictly not all
that important since these are in parts of refs that are implementing the
actual file storage backend but on the other hand it will not hurt either.

Signed-off-by: Ronnie Sahlberg <sahlberg@google.com>
Acked-by: Michael Haggerty <mhagger@alum.mit.edu>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

Describe one last minute one-liner fix for regression introduced in
1.9, and fix a grave mischaracterization on a recent remote-hg/bzr
change, pointed out by Felipe.

Signed-off-by: Junio C Hamano <gitster@pobox.com>

Fixes a regression in 1.9.0 with an obviously correct single-liner.

* cl/p4-use-diff-tree:
  git-p4: format-patch to diff-tree change breaks binary patches

When applying binary patches a full index is required. format-patch
already handles this, but diff-tree needs '--full-index' argument
to always output full index. When git-p4 runs git-apply to test
the patch, git-apply rejects the patch due to abbreviated blob
object names. This is the error message git-apply emits in this
case:

    error: cannot apply binary patch to '<filename>' without full index line
    error: <filename>: patch does not apply

Signed-off-by: Tolga Ceylan <tolga.ceylan@gmail.com>
Acked-by: Pete Wyckoff <pw@padd.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

Signed-off-by: Øyvind A. Holm <sunny@sunbase.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

A finishing touch fix to a new change already in 'master'.

* mw/symlinks:
  setup: fix windows path buffer over-stepping

* km/git-svn-workaround-older-getopt-long:
  t9117: use --prefix "" instead of --prefix=""

* rh/prompt-pcmode-avoid-eval-on-refname:
  git-prompt.sh: don't put unsanitized branch names in $PS1