When cloning to a directory "C:\foo\bar" from Windows' cmd.exe where
"foo" does not exist yet, Git would throw an error like

    fatal: could not create work tree dir 'c:\foo\bar'.: No such file or directory

Fix this by not hard-coding a platform specific directory separator
into safe_create_leading_directories().

This patch, including its entire commit message, is derived from a
patch by Sebastian Schuberth.
Signed-off-by: NJohannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: NSebastian Schuberth <sschuberth@gmail.com>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>
Signed-off-by: NMichael Haggerty <mhagger@alum.mit.edu>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

If safe_create_leading_directories() fails because a file along the
path unexpectedly vanished, try again from the beginning.  Try at most
4 times.
Signed-off-by: NMichael Haggerty <mhagger@alum.mit.edu>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

This doesn't seem to be a likely error, but we've got the counter
anyway, so we might as well use it for an added bit of safety.

Please note that the first call to rename() is optimistic, and it is
normal for it to fail if there is a directory in the way.  So bump the
total number of allowed attempts to 4, to be sure that we can still
have at least 3 retries in the case of a race.
Signed-off-by: NMichael Haggerty <mhagger@alum.mit.edu>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

If a directory vanishes while renaming the temporary reflog file,
retry (up to 3 times).  This could happen if another process deletes
the directory created by safe_create_leading_directories() just before
we rename the file into the directory.

As far as I can tell, this race could not occur internal to git.  The
only time that a directory under $GIT_DIR/logs is deleted is if room
has to be made for a log file for a reference with the same name;
for example, in the following sequence:

    git branch foo/bar    # Creates file .git/logs/refs/heads/foo/bar
    git branch -d foo/bar # Deletes file but leaves .git/logs/refs/heads/foo/
    git branch foo        # Deletes .git/logs/refs/heads/foo/

But the only reason the last command deletes the directory is because
it wants to create a file with the same name.  So if another process
(e.g.,

    git branch foo/baz

) wants to create that directory, one of the two is doomed to failure
anyway because of a D/F conflict.
Signed-off-by: NMichael Haggerty <mhagger@alum.mit.edu>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

It's about to become a bit more complex.
Signed-off-by: NMichael Haggerty <mhagger@alum.mit.edu>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

If a file or directory that we are trying to remove disappears (e.g.,
because another process has pruned it), do not consider it an error.

However, if REMOVE_DIR_KEEP_TOPLEVEL is set, and the toplevel
directory is missing, then consider it an error (like before).
Signed-off-by: NMichael Haggerty <mhagger@alum.mit.edu>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

If opendir() fails on the top-level directory, it makes sense to try
to delete it anyway--but only if the failure was due to EACCES.
Signed-off-by: NMichael Haggerty <mhagger@alum.mit.edu>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

If hold_lock_file_for_update() fails with errno==ENOENT, it might be
because somebody else (for example, a pack-refs process) has just
deleted one of the lockfile's ancestor directories.  So if this
condition is detected, try again (up to 3 times).
Signed-off-by: NMichael Haggerty <mhagger@alum.mit.edu>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

If safe_create_leading_directories() fails because a file along the
path unexpectedly vanished, try again (up to 3 times).

This can occur if another process is deleting directories at the same
time as we are trying to make them.  For example, "git pack-refs
--all" tries to delete the loose refs and any empty directories that
are left behind.  If a pack-refs process is running, then it might
delete a directory that we need to put a new loose reference in.

If safe_create_leading_directories() thinks this might have happened,
then take its advice and try again (maximum three attempts).
Signed-off-by: NMichael Haggerty <mhagger@alum.mit.edu>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

Add a new possible error result that can be returned by
safe_create_leading_directories() and
safe_create_leading_directories_const(): SCLD_VANISHED.  This value
indicates that a file or directory on the path existed at one point
(either it already existed or the function created it), but then it
disappeared.  This probably indicates that another process deleted the
directory while we were working.  If SCLD_VANISHED is returned, the
caller might want to retry the function call, as there is a chance
that a new attempt will succeed.

Why doesn't safe_create_leading_directories() do the retrying
internally?  Because an empty directory isn't really ever safe until
it holds a file.  So even if safe_create_leading_directories() were
absolutely sure that the directory existed before it returned, there
would be no guarantee that the directory still existed when the caller
tried to write something in it.
Signed-off-by: NMichael Haggerty <mhagger@alum.mit.edu>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

safe_create_leading_directories_const() returns a non-zero value on
error.  The old code at this calling site recognized a couple of
particular error values, and treated all other return values as
success.  Instead, be more conservative: recognize the errors we are
interested in, but treat any other nonzero values as failures.  This
is more robust in case somebody adds another possible return value
without telling us.
Signed-off-by: NMichael Haggerty <mhagger@alum.mit.edu>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

Instead of returning magic integer values (which a couple of callers
go to the trouble of distinguishing), return values from an enum.  Add
a docstring.
Signed-off-by: NMichael Haggerty <mhagger@alum.mit.edu>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

Always restore the slash that we scribbled over at the end of the
loop, rather than also fixing it up at each premature exit from the
loop.  This makes it harder to forget to do the cleanup as new paths
are added to the code.
Signed-off-by: NMichael Haggerty <mhagger@alum.mit.edu>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

If the input path has multiple slashes between path components (e.g.,
"foo//bar"), then the old code was breaking the path at the last
slash, not the first one.  So in the above example, the second slash
was overwritten with NUL, resulting in the parent directory being
sought as "foo/".

When stat() is called on "foo/", it fails with ENOTDIR if "foo" exists
but is not a directory.  This caused the wrong path to be taken in the
subsequent logic.

So instead, split path components at the first intercomponent slash
rather than the last one.
Signed-off-by: NMichael Haggerty <mhagger@alum.mit.edu>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

Rename "pos" to "next_component", because now it always points at the
next component of the path name that has to be processed.
Signed-off-by: NMichael Haggerty <mhagger@alum.mit.edu>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

Keep track of the position of the slash character independently of
"pos", thereby making the purpose of each variable clearer and
working towards other upcoming changes.
Signed-off-by: NMichael Haggerty <mhagger@alum.mit.edu>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

This makes it more obvious that values of "st" don't persist across
loop iterations.
Signed-off-by: NMichael Haggerty <mhagger@alum.mit.edu>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

Signed-off-by: NMichael Haggerty <mhagger@alum.mit.edu>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

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

* rs/doc-submitting-patches:
  SubmittingPatches: document how to handle multiple patches

* tr/doc-git-cherry:
  Documentation: revamp git-cherry(1)

* nd/glossary-content-pathspec-markup:
  glossary-content.txt: fix documentation of "**" patterns

* jj/doc-markup-gitcli:
  Documentation/gitcli.txt: fix double quotes

* jj/doc-markup-hints-in-coding-guidelines:
  State correct usage of literal examples in man pages in the coding standards

* jj/log-doc:
  Documentation/git-log.txt: mark-up fix and minor rephasing
  Documentation/git-log: update "--log-size" description

* jj/rev-list-options-doc:
  Documentation/rev-list-options.txt: fix some grammatical issues and typos
  Documentation/rev-list-options.txt: fix mark-up

* tb/doc-fetch-pack-url:
  git-fetch-pack uses URLs like git-fetch

* mi/typofixes:
  contrib: typofixes
  Documentation/technical/http-protocol.txt: typofixes
  typofixes: fix misspelt comments

Two processes creating loose objects at the same time could have
failed unnecessarily when the name of their new objects started
with the same byte value, due to a race condition.

* jh/loose-object-dirs-creation-race:
  sha1_file.c:create_tmpfile(): Fix race when creating loose object dirs

"git am --abort" sometimes complained about not being able to write
a tree with an 0{40} object in it.

* jk/two-way-merge-corner-case-fix:
  t1005: add test for "read-tree --reset -u A B"
  t1005: reindent
  unpack-trees: fix "read-tree -u --reset A B" with conflicted index

"git cat-file --batch-check=ok" did not check the existence of the
named object.

* sb/sha1-loose-object-info-check-existence:
  sha1_loose_object_info(): do not return success on missing object

"git diff -- ':(icase)makefile'" was unnecessarily rejected at the
command line parser.

* nd/magic-pathspec:
  diff: restrict pathspec limitations to diff b/f case only

Its value is the same as the number of entries in the "names"
string_list, so just use "names.nr" in its place.
Signed-off-by: NMichael Haggerty <mhagger@alum.mit.edu>
Acked-by: NStefan Beller <stefanbeller@googlemail.com>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

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

The usage sample of add_submodule_odb() function in the Submodules
section expects non-zero return value for success, but the function
actually reports success with zero.
Helped-by: NRené Scharfe <l.s.r@web.de>
Reviewed-by: NHeiko Voigt <hvoigt@hvoigt.net>
Signed-off-by: NNick Townsend <nick.townsend@mac.com>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

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

When submodule.$name.update is given as hint from the upstream in
the .gitmodules file, we used to blindly copy it to .git/config,
unless there already is a value defined for the submodule.

However, there is no reason to expect that the update mode hinted by
the upstream is available in the version of Git the user is using,
and a really custom "!cmd" prepared by an upstream person running on
Linux may not even be available to a user on Windows.  It is simply
irresponsible to copy the setting blindly and to attempt to use it
during a later "submodule update" without validating it first.

Just show the suggested value to the diagnostic output, and set the
value to 'none' in the configuration, if it is not one of the ones
that are known to be supported by this version of Git.
Helped-by: NJens Lehmann <Jens.Lehmann@web.de>
Helped-by: NJeff King <peff@peff.net>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

git-cherry(1)'s "description" section has never really managed
to explain to me what the command does.  It contains too much
explanation of the algorithm instead of simply saying what
goals it achieves, and too much terminology that we otherwise
do not use (fork-point instead of merge-base).

Try a much more concise approach: state what it finds out, why
this is neat, and how the output is formatted, in a few short
paragraphs.  In return, provide much longer examples of how it
fits into a "format-patch | am" based workflow, and how it
compares to reading the same from git-log.

Also carefully avoid using "merge" in a context where it does
not mean something that comes from git-merge(1).  Instead, say
"apply" in an attempt to further link to patch workflow
concepts.

While there, also omit the language about _which_ upstream
branch we treat as the default.  I literally just learned that
we support having several, so let's not confuse new users
here, especially considering that git-config(1) does not
document this.

Prompted-by: a.huemer@commend.com on #git
Signed-off-by: NThomas Rast <tr@thomasrast.ch>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

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