git init --shared=0xxx, where '0xxx' is an octal number, will create
a repository with file modes set to '0xxx'. Users with a safe umask
value (0077) can use this option to force file modes. For example,
'0640' is a group-readable but not group-writable regardless of
user's umask value. Values compatible with old Git versions are written
as they were before, for compatibility reasons. That is, "1" for
"group" and "2" for "everybody".

"git config core.sharedRepository 0xxx" is also handled.
Signed-off-by: NHeikki Orsila <heikki.orsila@iki.fi>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

This new function can be used by config parsers to tell if a variable
is simply set, set to 1, or set to "true".
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

This is in an effort to make the source index of 'unpack_trees()' as
being const, and thus making the compiler help us verify that we only
access it for reading.

The constification also extended to some of the hashing helpers that get
called indirectly.
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

This new helper is identical to base_name_compare(), except it compares
conflicting directory/file entries as equal in order to help handling DF
conflicts (thus the name).

Note that while a directory name compares as equal to a regular file
with the new helper, they then individually compare _differently_ to a
filename that has a dot after the basename (because '\0' < '.' < '/').

So a directory called "foo/" will compare equal to a file "foo", even
though "foo.c" will compare after "foo" and before "foo/"

This will be used by routines that want to traverse the git namespace
but then handle conflicting entries together when possible.
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

The requirements are:
* it may not crash on NULL pointers
* a callback function is needed, as index-pack/unpack-objects
  need to do different things
* the type information is needed to check the expected <-> real type
  and print better error messages
Signed-off-by: NMartin Koegler <mkoegler@auto.tuwien.ac.at>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

Originally by Kristian Hï¿œgsberg; I fixed the conversion of rerere, which
had a different API.
Signed-off-by: NDaniel Barkalow <barkalow@iabervon.org>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

This converts git_config_alias to the public alias_lookup
function. Because of the nature of our config parser, we
still have to rely on setting static data. However, that
interface is wrapped so that you can just say

  value = alias_lookup(key);
Signed-off-by: NJeff King <peff@peff.net>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

This is used by git-apply but we can use it elsewhere by slightly
generalizing it.
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

We used to just memcpy() the index entry when we copied the stat() and
SHA1 hash information, which worked well enough back when the index
entry was just an exact bit-for-bit representation of the information on
disk.

However, these days we actually have various management information in
the cache entry too, and we should be careful to not overwrite it when
we copy the stat information from another index entry.
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

This makes the name hash removal function (which really just sets the
bit that disables lookups of it) available to external routines, and
makes read_cache_unmerged() use it when it drops an unmerged entry from
the index.

It's renamed to remove_index_entry(), and we drop the (unused) 'istate'
argument.
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

We handled the case of removing and re-inserting cache entries badly,
which is something that merging commonly needs to do (removing the
different stages, and then re-inserting one of them as the merged
state).

We even had a rather ugly special case for this failure case, where
replace_index_entry() basically turned itself into a no-op if the new
and the old entries were the same, exactly because the hash routines
didn't handle it on their own.

So what this patch does is to not just have the UNHASHED bit, but a
HASHED bit too, and when you insert an entry into the name hash, that
involves:

 - clear the UNHASHED bit, because now it's valid again for lookup
   (which is really all that UNHASHED meant)

 - if we're being lazy, we're done here (but we still want to clear the
   UNHASHED bit regardless of lazy mode, since we can become unlazy
   later, and so we need the UNHASHED bit to always be set correctly,
   even if we never actually insert the entry into the hash list)

 - if it was already hashed, we just leave it on the list

 - otherwise mark it HASHED and insert it into the list

this all means that unhashing and rehashing a name all just works
automatically.  Obviously, you cannot change the name of an entry (that
would be a serious bug), but nothing can validly do that anyway (you'd
have to allocate a new struct cache_entry anyway since the name length
could change), so that's not a new limitation.

The code actually gets simpler in many ways, although the lazy hashing
does mean that there are a few odd cases (ie something can be marked
unhashed even though it was never on the hash in the first place, and
isn't actually marked hashed!).
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

"git branch" and "git checkout -b" now honor --track option even when
the upstream branch is local.  Previously --track was silently ignored
when forking from a local branch.  Also the command did not error out
when --track was explicitly asked for but the forked point specified
was not an existing branch (i.e. when there is no way to set up the
tracking configuration), but now it correctly does.

The configuration setting branch.autosetupmerge can now be set to
"always", which is equivalent to using --track from the command line.
Setting branch.autosetupmerge to "true" will retain the former behavior
of only setting up branch.*.merge for remote upstream branches.

Includes test cases for the new functionality.
Signed-off-by: NJay Soffian <jaysoffian@gmail.com>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

This helper function is the core of "$object^{type}" parser.
Now it is made available to callers outside sha1_name.c

Also use "git_config_string" to simplify "config.c" code
where "excludes_file" is set.
Signed-off-by: NChristian Couder <chriscool@tuxfamily.org>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

Also use "git_config_string" to simplify "config.c" code
where "editor_program" is set.
Signed-off-by: NChristian Couder <chriscool@tuxfamily.org>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

Also use "git_config_string" to simplify "config.c" code
where "pager_program" is set.
Signed-off-by: NChristian Couder <chriscool@tuxfamily.org>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

In many places we just check if a value from the config file is not
NULL, then we duplicate it and return 0. This patch introduces the new
'git_config_string' function to do that.

This function is also used to refactor some code in 'config.c'.
Refactoring other files is left for other patches.

Also not all the code in "config.c" is refactored, because the function
takes a "const char **" as its first parameter, but in many places a
"char *" is used instead of a "const char *". (And C does not allow
using a "char **" instead of a "const char **" without a warning.)
Signed-off-by: NChristian Couder <chriscool@tuxfamily.org>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

This is used to report misconfigured configuration file that does not
give any value to a non-boolean variable, e.g.

	[section]
		var

It is perfectly fine to say it if the section.var is a boolean (it means
true), but if a variable expects a string value it should be flagged as
a configuration error.
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

It's small, but it was in three places already, so it should be in the
library.
Signed-off-by: NDaniel Barkalow <barkalow@iabervon.org>

The GIT_CONFIG_NOGLOBAL and GIT_CONFIG_NOSYSTEM environment
variables are magic undocumented switches that can be used
to ensure a totally clean environment. This is necessary for
running reliable tests, since those config files may contain
settings that change the outcome of tests.
Signed-off-by: NJeff King <peff@peff.net>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

CRLF conversion bears a slight chance of corrupting data.
autocrlf=true will convert CRLF to LF during commit and LF to
CRLF during checkout.  A file that contains a mixture of LF and
CRLF before the commit cannot be recreated by git.  For text
files this is the right thing to do: it corrects line endings
such that we have only LF line endings in the repository.
But for binary files that are accidentally classified as text the
conversion can corrupt data.

If you recognize such corruption early you can easily fix it by
setting the conversion type explicitly in .gitattributes.  Right
after committing you still have the original file in your work
tree and this file is not yet corrupted.  You can explicitly tell
git that this file is binary and git will handle the file
appropriately.

Unfortunately, the desired effect of cleaning up text files with
mixed line endings and the undesired effect of corrupting binary
files cannot be distinguished.  In both cases CRLFs are removed
in an irreversible way.  For text files this is the right thing
to do because CRLFs are line endings, while for binary files
converting CRLFs corrupts data.

This patch adds a mechanism that can either warn the user about
an irreversible conversion or can even refuse to convert.  The
mechanism is controlled by the variable core.safecrlf, with the
following values:

 - false: disable safecrlf mechanism
 - warn: warn about irreversible conversions
 - true: refuse irreversible conversions

The default is to warn.  Users are only affected by this default
if core.autocrlf is set.  But the current default of git is to
leave core.autocrlf unset, so users will not see warnings unless
they deliberately chose to activate the autocrlf mechanism.

The safecrlf mechanism's details depend on the git command.  The
general principles when safecrlf is active (not false) are:

 - we warn/error out if files in the work tree can modified in an
   irreversible way without giving the user a chance to backup the
   original file.

 - for read-only operations that do not modify files in the work tree
   we do not not print annoying warnings.

There are exceptions.  Even though...

 - "git add" itself does not touch the files in the work tree, the
   next checkout would, so the safety triggers;

 - "git apply" to update a text file with a patch does touch the files
   in the work tree, but the operation is about text files and CRLF
   conversion is about fixing the line ending inconsistencies, so the
   safety does not trigger;

 - "git diff" itself does not touch the files in the work tree, it is
   often run to inspect the changes you intend to next "git add".  To
   catch potential problems early, safety triggers.

The concept of a safety check was originally proposed in a similar
way by Linus Torvalds.  Thanks to Dimitry Potapov for insisting
on getting the naked LF/autocrlf=true case right.
Signed-off-by: NSteffen Prohaska <prohaska@zib.de>

A pattern "foo/" in the exclude list did not match directory
"foo", but a pattern "foo" did.  This attempts to extend the
exclude mechanism so that it would while not matching a regular
file or a symbolic link "foo".  In order to differentiate a
directory and non directory, this passes down the type of path
being checked to excluded() function.

A downside is that the recursive directory walk may need to run
lstat(2) more often on systems whose "struct dirent" do not give
the type of the entry; earlier it did not have to do so for an
excluded path, but we now need to figure out if a path is a
directory before deciding to exclude it.  This is especially bad
because an idea similar to the earlier CE_UPTODATE optimization
to reduce number of lstat(2) calls would by definition not apply
to the codepaths involved, as (1) directories will not be
registered in the index, and (2) excluded paths will not be in
the index anyway.
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

This new error mode allows a line to have a carriage return at the
end of the line when checking and fixing trailing whitespace errors.

Some people like to keep CRLF line ending recorded in the repository,
and still want to take advantage of the automated trailing whitespace
stripping.  We still show ^M in the diff output piped to "less" to
remind them that they do have the CR at the end, but these carriage
return characters at the end are no longer flagged as errors.
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

This delays the hashing of index names until it becomes necessary for
the first time.
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

This creates a hash index of every single file added to the index.
Right now that hash index isn't actually used for much: I implemented a
"cache_name_exists()" function that uses it to efficiently look up a
filename in the index without having to do the O(logn) binary search,
but quite frankly, that's not why this patch is interesting.

No, the whole and only reason to create the hash of the filenames in the
index is that by modifying the hash function, you can fairly easily do
things like making it always hash equivalent names into the same bucket.

That, in turn, means that suddenly questions like "does this name exist
in the index under an _equivalent_ name?" becomes much much cheaper.

Guiding principles behind this patch:

 - it shouldn't be too costly. In fact, my primary goal here was to
   actually speed up "git commit" with a fully populated kernel tree, by
   being faster at checking whether a file already existed in the index. I
   did succeed, but only barely:

	Best before:
		[torvalds@woody linux]$ time git commit > /dev/null
		real    0m0.255s
		user    0m0.168s
		sys     0m0.088s

	Best after:

		[torvalds@woody linux]$ time ~/git/git commit > /dev/null
		real    0m0.233s
		user    0m0.144s
		sys     0m0.088s

   so some things are actually faster (~8%).

   Caveat: that's really the best case. Other things are invariably going
   to be slightly slower, since we populate that index cache, and quite
   frankly, few things really use it to look things up.

   That said, the cost is really quite small. The worst case is probably
   doing a "git ls-files", which will do very little except puopulate the
   index, and never actually looks anything up in it, just lists it.

	Before:
		[torvalds@woody linux]$ time git ls-files > /dev/null
		real    0m0.016s
		user    0m0.016s
		sys     0m0.000s

	After:
		[torvalds@woody linux]$ time ~/git/git ls-files > /dev/null
		real    0m0.021s
		user    0m0.012s
		sys     0m0.008s

   and while the thing has really gotten relatively much slower, we're
   still talking about something almost unmeasurable (eg 5ms). And that
   really should be pretty much the worst case.

   So we lose 5ms on one "benchmark", but win 22ms on another. Pick your
   poison - this patch has the advantage that it will _likely_ speed up
   the cases that are complex and expensive more than it slows down the
   cases that are already so fast that nobody cares. But if you look at
   relative speedups/slowdowns, it doesn't look so good.

 - It should be simple and clean

   The code may be a bit subtle (the reasons I do hash removal the way I
   do etc), but it re-uses the existing hash.c files, so it really is
   fairly small and straightforward apart from a few odd details.

Now, this patch on its own doesn't really do much, but I think it's worth
looking at, if only because if done correctly, the name hashing really can
make an improvement to the whole issue of "do we have a filename that
looks like this in the index already". And at least it gets real testing
by being used even by default (ie there is a real use-case for it even
without any insane filesystems).

NOTE NOTE NOTE! The current hash is a joke. I'm ashamed of it, I'm just
not ashamed of it enough to really care. I took all the numbers out of my
nether regions - I'm sure it's good enough that it works in practice, but
the whole point was that you can make a really much fancier hash that
hashes characters not directly, but by their upper-case value or something
like that, and thus you get a case-insensitive hash, while still keeping
the name and the index itself totally case sensitive.
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

Aside from the lstat(2) done for work tree files, there are
quite many lstat(2) calls in refname dwimming codepath.  This
patch is not about reducing them.

 * It adds a new ce_flag, CE_UPTODATE, that is meant to mark the
   cache entries that record a regular file blob that is up to
   date in the work tree.  If somebody later walks the index and
   wants to see if the work tree has changes, they do not have
   to be checked with lstat(2) again.

 * fill_stat_cache_info() marks the cache entry it just added
   with CE_UPTODATE.  This has the effect of marking the paths
   we write out of the index and lstat(2) immediately as "no
   need to lstat -- we know it is up-to-date", from quite a lot
   fo callers:

    - git-apply --index
    - git-update-index
    - git-checkout-index
    - git-add (uses add_file_to_index())
    - git-commit (ditto)
    - git-mv (ditto)

 * refresh_cache_ent() also marks the cache entry that are clean
   with CE_UPTODATE.

 * write_index is changed not to write CE_UPTODATE out to the
   index file, because CE_UPTODATE is meant to be transient only
   in core.  For the same reason, CE_UPDATE is not written to
   prevent an accident from happening.
Signed-off-by: NJunio C Hamano <gitster@pobox.com>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

We currently use lower 12-bit (masked with CE_NAMEMASK) in the
ce_flags field to store the length of the name in cache_entry,
without checking the length parameter given to
create_ce_flags().  This can make us store incorrect length.

Currently we are mostly protected by the fact that many
codepaths first copy the path in a variable of size PATH_MAX,
which typically is 4096 that happens to match the limit, but
that feels like a bug waiting to happen.  Besides, that would
not allow us to shorten the width of CE_NAMEMASK to use the bits
for new flags.

This redefines the meaning of the name length stored in the
cache_entry.  A name that does not fit is represented by storing
CE_NAMEMASK in the field, and the actual length needs to be
computed by actually counting the bytes in the name[] field.
This way, only the unusually long paths need to suffer.
Signed-off-by: NJunio C Hamano <gitster@pobox.com>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

This converts the index explicitly on read and write to its on-disk
format, allowing the in-core format to contain more flags, and be
simpler.

In particular, the in-core format is now host-endian (as opposed to the
on-disk one that is network endian in order to be able to be shared
across machines) and as a result we can dispense with all the
htonl/ntohl on accesses to the cache_entry fields.

This will make it easier to make use of various temporary flags that do
not exist in the on-disk format.
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

fast-import was relying on the fact that on most systems mmap() and
write() are synchronized by the filesystem's buffer cache.  We were
relying on the ability to mmap() 20 bytes beyond the current end
of the file, then later fill in those bytes with a future write()
call, then read them through the previously obtained mmap() address.

This isn't always true with some implementations of NFS, but it is
especially not true with our NO_MMAP=YesPlease build time option used
on some platforms.  If fast-import was built with NO_MMAP=YesPlease
we used the malloc()+pread() emulation and the subsequent write()
call does not update the trailing 20 bytes of a previously obtained
"mmap()" (aka malloc'd) address.

Under NO_MMAP that behavior causes unpack_entry() in sha1_file.c to
be unable to read an object header (or data) that has been unlucky
enough to be written to the packfile at a location such that it
is in the trailing 20 bytes of a window previously opened on that
same packfile.

This bug has gone unnoticed for a very long time as it is highly data
dependent.  Not only does the object have to be placed at the right
position, but it also needs to be positioned behind some other object
that has been accessed due to a branch cache invalidation.  In other
words the stars had to align just right, and if you did run into
this bug you probably should also have purchased a lottery ticket.

Fortunately the workaround is a lot easier than the bug explanation.

Before we allow unpack_entry() to read data from a pack window
that has also (possibly) been modified through write() we force
all existing windows on that packfile to be closed.  By closing
the windows we ensure that any new access via the emulated mmap()
will reread the packfile, updating to the current file content.

This comes at a slight performance degredation as we cannot reuse
previously cached windows when we update the packfile.  But it
is a fairly minor difference as the window closes happen at only
two points:

 - When the packfile is finalized and its .idx is generated:

   At this stage we are getting ready to update the refs and any
   data access into the packfile is going to be random, and is
   going after only the branch tips (to ensure they are valid).
   Our existing windows (if any) are not likely to be positioned
   at useful locations to access those final tip commits so we
   probably were closing them before anyway.

 - When the branch cache missed and we need to reload:

   At this point fast-import is getting change commands for the next
   commit and it needs to go re-read a tree object it previously
   had written out to the packfile.  What windows we had (if any)
   are not likely to cover the tree in question so we probably were
   closing them before anyway.

We do try to avoid unnecessarily closing windows in the second case
by checking to see if the packfile size has increased since the
last time we called unpack_entry() on that packfile.  If the size
has not changed then we have not written additional data, and any
existing window is still vaild.  This nicely handles the cases where
fast-import is going through a branch cache reload and needs to read
many trees at once.  During such an event we are not likely to be
updating the packfile so we do not cycle the windows between reads.

With this change in place t9301-fast-export.sh (which was broken
by c3b0dec5) finally works again.
Signed-off-by: NShawn O. Pearce <spearce@spearce.org>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

The lockfile API is a handy way to obtain a file that is cleaned
up if you die().  But sometimes you would need this sequence to
work:

 1. hold_lock_file_for_update() to get a file descriptor for
    writing;

 2. write the contents out, without being able to decide if the
    results should be committed or rolled back;

 3. do something else that makes the decision --- and this
    "something else" needs the lockfile not to have an open file
    descriptor for writing (e.g. Windows do not want a open file
    to be renamed);

 4. call commit_lock_file() or rollback_lock_file() as
    appropriately.

This adds close_lock_file() you can call between step 2 and 3 in
the above sequence.
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

This commit unifies three separate places where whitespace checking was
performed:

 - the whitespace checking previously done in builtin-apply.c is
extracted into a function in ws.c

 - the equivalent logic in "git diff" is removed

 - the emit_line_with_ws() function is also removed because that also
rechecks the whitespace, and its functionality is rolled into ws.c

The new function is called check_and_emit_line() and it does two things:
checks a line for whitespace errors and optionally emits it. The checking
is based on lines of content rather than patch lines (in other words, the
caller must strip the leading "+" or "-"); this was suggested by Junio on
the mailing list to allow for a future extension to "git show" to display
whitespace errors in blobs.

At the same time we teach it to report all classes of whitespace errors
found for a given line rather than reporting only the first found error.
Signed-off-by: NWincent Colaiuta <win@wincent.com>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

When deciding whether or not to turn on automatic color
support, git_config_colorbool checks whether stdout is a
tty. However, because we run a pager, if stdout is not a
tty, we must check whether it is because we started the
pager. This used to be done by checking the pager_in_use
variable.

This variable was set only when the git program being run
started the pager; there was no way for an external program
running git indicate that it had already started a pager.
This patch allows a program to set GIT_PAGER_IN_USE to a
true value to indicate that even though stdout is not a tty,
it is because a pager is being used.
Signed-off-by: NJeff King <peff@peff.net>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

An earlier fix to the said commit was incomplete; it mixed up the
meaning of the flag parameter passed to the internal fmt_ident()
function, so this corrects it.

git_author_info() and git_committer_info() can be told to issue a
warning when no usable user information is found, and optionally can be
told to error out.  Operations that actually use the information to
record a new commit or a tag will still error out, but the caller to
leave reflog record will just silently use bogus user information.

Not warning on misconfigured user information while writing a reflog
entry is somewhat debatable, but it is probably nicer to the users to
silently let it pass, because the only information you are losing is who
checked out the branch.

 * git_author_info() and git_committer_info() used to take 1 (positive
   int) to error out with a warning on misconfiguration; this is now
   signalled with a symbolic constant IDENT_ERROR_ON_NO_NAME.

 * These functions used to take -1 (negative int) to warn but continue;
   this is now signalled with a symbolic constant IDENT_WARN_ON_NO_NAME.

 * fmt_ident() function implements the above error reporting behaviour
   common to git_author_info() and git_committer_info().  A symbolic
   constant IDENT_NO_DATE can be or'ed in to the flag parameter to make
   it return only the "Name <email@address.xz>".

 * fmt_name() is a thin wrapper around fmt_ident() that always passes
   IDENT_ERROR_ON_NO_NAME and IDENT_NO_DATE.
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

The `core.whitespace` configuration variable allows you to define what
`diff` and `apply` should consider whitespace errors for all paths in
the project (See gitlink:git-config[1]).  This attribute gives you finer
control per path.

For example, if you have these in the .gitattributes:

    frotz   whitespace
    nitfol  -whitespace
    xyzzy   whitespace=-trailing

all types of whitespace problems known to git are noticed in path 'frotz'
(i.e. diff shows them in diff.whitespace color, and apply warns about
them), no whitespace problem is noticed in path 'nitfol', and the
default types of whitespace problems except "trailing whitespace" are
noticed for path 'xyzzy'.  A project with mixed Python and C might want
to have:

    *.c    whitespace
    *.py   whitespace=-indent-with-non-tab

in its toplevel .gitattributes file.
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

Now that str_buf takes care of all the allocations, there is
no more gain to pass an argument count.

So this patch removes the "count" argument from:
	- "sq_quote_argv"
	- "trace_argv_printf"
and all the callers.
Signed-off-by: NChristian Couder <chriscool@tuxfamily.org>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

Introduce fmt_name() specifically meant for formatting the name and
email pair, to add signed-off-by value.  This reverts parts of
13208572 (builtin-commit: fix --signoff)
so that an empty datestamp string given to fmt_ident() by mistake will
error out as before.
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

When we consider if a path has been totally rewritten, we did not
touch changes from symlinks to files or vice versa.  But a change
that modifies even the type of a blob surely should count as a
complete rewrite.

While we are at it, modernise diffcore-break to be aware of gitlinks (we
do not want to touch them).
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

This separates the logic to limit the extent of change to the
index by where you are (controlled by "prefix") and what you
specify from the command line (controlled by "pathspec").
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

This exports three helper functions from ls-files.

 * pathspec_match() checks if a given path matches a set of pathspecs
   and optionally records which pathspec was used.  This function used
   to be called "match()" but renamed to be a bit less vague.

 * report_path_error() takes a set of pathspecs and the record
   pathspec_match() above leaves, and gives error message.  This
   was split out of the main function of ls-files.

 * overlay_tree_on_cache() takes a tree-ish (typically "HEAD")
   and overlays it on the current in-core index.  By iterating
   over the resulting index, the caller can find out the paths
   in either the index or the HEAD.  This function used to be
   called "overlay_tree()" but renamed to be a bit more
   descriptive.
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

The old rules used by fetch were coded as a series of ifs.  The old
rules are:
1) match full refname if it starts with "refs/" or matches "HEAD"
2) verify that full refname starts with "refs/"
3) match abbreviated name in "refs/" if it starts with "heads/",
    "tags/", or "remotes/".
4) match abbreviated name in "refs/heads/"

This is replaced by the new rules
a) match full refname
b) match abbreviated name prefixed with "refs/"
c) match abbreviated name prefixed with "refs/heads/"

The details of the new rules are different from the old rules.  We no
longer verify that the full refname starts with "refs/".  The new rule
(a) matches any full string.  The old rules (1) and (2) were stricter.
Now, the caller is responsible for using sensible full refnames.  This
should be the case for the current code.  The new rule (b) is less
strict than old rule (3).  The new rule accepts abbreviated names that
start with a non-standard prefix below "refs/".

Despite this modifications the new rules should handle all cases as
expected.  Two tests are added to verify that fetch does not resolve
short tags or HEAD in remotes.

We may even think about loosening the rules a bit more and unify them
with the rev-parse rules.  This would be done by replacing
ref_ref_fetch_rules with ref_ref_parse_rules.  Note, the two new test
would break.
Signed-off-by: NSteffen Prohaska <prohaska@zib.de>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>