When MyDir/ABC/filea.txt is added to Git, the disk directory MyDir/ABC/
is renamed to mydir/aBc/, and then mydir/aBc/fileb.txt is added, the
index will contain MyDir/ABC/filea.txt and mydir/aBc/fileb.txt. Although
the earlier portions of this patch series account for those differences
in case, this patch makes the pathing consistent by folding the case of
newly added files against the first file added with that path.

In read-cache.c's add_to_index(), the index_name_exists() support used
for git status's case insensitive directory lookups is used to find the
proper directory case according to what the user already checked in.
That is, MyDir/ABC/'s case is used to alter the stored path for
fileb.txt to MyDir/ABC/fileb.txt (instead of mydir/aBc/fileb.txt).

This is especially important when cloning a repository to a case
sensitive file system. MyDir/ABC/ and mydir/aBc/ exist in the same
directory on a Windows machine, but on Linux, the files exist in two
separate directories. The update to add_to_index(), in effect, treats a
Windows file system as case sensitive by making path case consistent.
Signed-off-by: NJoshua Jensen <jjensen@workspacewhiz.com>
Signed-off-by: NJohannes Sixt <j6t@kdbg.org>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

Noticed with valgrind.
Signed-off-by: NJonathan Nieder <jrnieder@gmail.com>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

The new dircache extension CACHE_EXT_RESOLVE_UNDO, whose value is
0x52455543, is actually the ASCII sequence 'REUC', not the ASCII
sequence 'REUN'.
Signed-off-by: NShawn O. Pearce <spearce@spearce.org>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

The rule has always been that a cache entry that is ce_uptodate(ce)
means that we already have checked the work tree entity and we know
there is no change in the work tree compared to the index, and nobody
should have to double check.  Note that false ce_uptodate(ce) does not
mean it is known to be dirty---it only means we don't know if it is
clean.

There are a few codepaths (refresh-index and preload-index are among
them) that mark a cache entry as up-to-date based solely on the return
value from ie_match_stat(); this function uses lstat() to see if the
work tree entity has been touched, and for a submodule entry, if its
HEAD points at the same commit as the commit recorded in the index of
the superproject (a submodule that is not even cloned is considered
clean).

A submodule is no longer considered unmodified merely because its HEAD
matches the index of the superproject these days, in order to prevent
people from forgetting to commit in the submodule and updating the
superproject index with the new submodule commit, before commiting the
state in the superproject.  However, the patch to do so didn't update
the codepath that marks cache entries up-to-date based on the updated
definition and instead worked it around by saying "we don't trust the
return value of ce_uptodate() for submodules."

This makes ce_uptodate() trustworthy again by not marking submodule
entries up-to-date.

The next step _could_ be to introduce a few "in-core" flag bits to
cache_entry structure to record "this entry is _known_ to be dirty",
call is_submodule_modified() from ie_match_stat(), and use these new
bits to avoid running this rather expensive check more than once, but
that can be a separate patch.
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

Exal Sibeaz pointed out that some git files are way too big, and that
add_files_to_cache() brings in all the diff machinery to any git binary
that needs the basic git SHA1 object operations from read-cache.c. Which
is pretty much all of them.

It's doubly silly, since add_files_to_cache() is only used by builtin
programs (add, checkout and commit), so it's fairly easily fixed by just
moving the thing to builtin-add.c, and avoiding the dependency entirely.

I initially argued to Exal that it would probably be best to try to depend
on smart compilers and linkers, but after spending some time trying to
make -ffunction-sections work and giving up, I think Exal was right, and
the fix is to just do some trivial cleanups like this.

This trivial cleanup results in pretty stunning file size differences.
The diff machinery really is mostly used by just the builtin programs, and
you have things like these trivial before-and-after numbers:

  -rwxr-xr-x 1 torvalds torvalds 1727420 2010-01-21 10:53 git-hash-object
  -rwxrwxr-x 1 torvalds torvalds  940265 2010-01-21 11:16 git-hash-object

Now, I'm not saying that 940kB is good either, but that's mostly all the
debug information - you can see the real code with 'size':

   text	   data	    bss	    dec	    hex	filename
 418675	   3920	 127408	 550003	  86473	git-hash-object (before)
 230650	   2288	 111728	 344666	  5425a	git-hash-object (after)

ie we have a nice 24% size reduction from this trivial cleanup.

It's not just that one file either. I get:

	[torvalds@nehalem git]$ du -s /home/torvalds/libexec/git-core
	45640	/home/torvalds/libexec/git-core (before)
	33508	/home/torvalds/libexec/git-core (after)

so we're talking 12MB of diskspace here.

(Of course, stripping all the binaries brings the 33MB down to 9MB, so the
whole debug information thing is still the bulk of it all, but that's a
separate issue entirely)

Now, I'm sure there are other things we should do, and changing our
compiler flags from -O2 to -Os would bring the text size down by an
additional almost 20%, but this thing Exal pointed out seems to be some
good low-hanging fruit.
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

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

Commit 9e8eceab (Add 'merge' mode to 'git reset', 2008-12-01) disallowed
"git reset --merge" when there was unmerged entries.  But it wished if
unmerged entries were reset as if --hard (instead of --merge) has been
used.  This makes sense because all "mergy" operations makes sure that
any path involved in the merge does not have local modifications before
starting, so resetting such a path away won't lose any information.

The previous commit changed the behavior of --merge to accept resetting
unmerged entries if they are reset to a different state than HEAD, but it
did not reset the changes in the work tree, leaving the conflict markers
in the resulting file in the work tree.

Fix it by doing three things:

 - Update the documentation to match the wish of original "reset --merge"
   better, namely, "An unmerged entry is a sign that the path didn't have
   any local modification and can be safely resetted to whatever the new
   HEAD records";

 - Update read_index_unmerged(), which reads the index file into the cache
   while dropping any higher-stage entries down to stage #0, not to copy
   the object name from the higher stage entry.  The code used to take the
   object name from the a stage entry ("base" if you happened to have
   stage #1, or "ours" if both sides added, etc.), which essentially meant
   that you are getting random results depending on what the merge did.

   The _only_ reason we want to keep a previously unmerged entry in the
   index at stage #0 is so that we don't forget the fact that we have
   corresponding file in the work tree in order to be able to remove it
   when the tree we are resetting to does not have the path.  In order to
   differentiate such an entry from ordinary cache entry, the cache entry
   added by read_index_unmerged() is marked as CE_CONFLICTED.

 - Update merged_entry() and deleted_entry() so that they pay attention to
   cache entries marked as CE_CONFLICTED.  They are previously unmerged
   entries, and the files in the work tree that correspond to them are
   resetted away by oneway_merge() to the version from the tree we are
   resetting to.
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

On big endian platforms with 8-byte unsigned long, the code reads the
size of the index extension section (which is a 4-byte network byte
order integer) incorrectly.
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

When resolving a conflict using "git add" to create a stage #0 entry, or
"git rm" to remove entries at higher stages, remove_index_entry_at()
function is eventually called to remove unmerged (i.e. higher stage)
entries from the index.  Introduce a "resolve_undo_info" structure and
keep track of the removed cache entries, and save it in a new index
extension section in the index_state.

Operations like "read-tree -m", "merge", "checkout [-m] <branch>" and
"reset" are signs that recorded information in the index is no longer
necessary.  The data is removed from the index extension when operations
start; they may leave conflicted entries in the index, and later user
actions like "git add" will record their conflicted states afresh.
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

Previously CE_MATCH_IGNORE_VALID flag is used by both valid and
skip-worktree bits. While the two bits have similar behaviour, sharing
this flag means "git update-index --really-refresh" will ignore
skip-worktree while it should not. Instead another flag is
introduced to ignore skip-worktree bit, CE_MATCH_IGNORE_VALID only
applies to valid bit.
Signed-off-by: NNguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

grep: turn on --cached for files that is marked skip-worktree
ls-files: do not check for deleted file that is marked skip-worktree
update-index: ignore update request if it's skip-worktree, while still allows removing
diff*: skip worktree version
Signed-off-by: NNguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

git reset without argument displays a summary of the local modification,
like this:

    $ git reset
    Makefile: locally modified

Some people have problems with this; they look like an error message.

This patch makes its output mimic how "git checkout $another_branch"
reports the paths with local modifications.  "git add --refresh --verbose"
is changed in the same way.

It also adds a header to make it clear that the output is informative,
and not an error.
Signed-off-by: NMatthieu Moy <Matthieu.Moy@imag.fr>

The change in the output is going to become more general than just saying
"changed", so let's make the variable name more general too.
Signed-off-by: NMatthieu Moy <Matthieu.Moy@imag.fr>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

Lots of die() calls did not actually report the kind of error, which
can leave the user confused as to the real problem.  Use die_errno()
where we check a system/library call that sets errno on failure, or
one of the following that wrap such calls:

  Function              Passes on error from
  --------              --------------------
  odb_pack_keep         open
  read_ancestry         fopen
  read_in_full          xread
  strbuf_read           xread
  strbuf_read_file      open or strbuf_read_file
  strbuf_readlink       readlink
  write_in_full         xwrite
Signed-off-by: NThomas Rast <trast@student.ethz.ch>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

Change calls to die(..., strerror(errno)) to use the new die_errno().

In the process, also make slight style adjustments: at least state
_something_ about the function that failed (instead of just printing
the pathname), and put paths in single quotes.
Signed-off-by: NThomas Rast <trast@student.ethz.ch>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

Commit e1afca4f "write_index(): update index_state->timestamp after
flushing to disk" on 2009-02-23 used stat.ctime to record the
timestamp of the index-file.  This is wrong, so fix this and use the
correct stat.mtime timestamp instead.

Commit 110c46a9 "Not all systems use st_[cm]tim field for ns
resolution file timestamp" on 2009-03-08, has a similar bug for the
builtin-fetch-pack.c file.
Signed-off-by: NKjetil Barvik <barvik@broadpark.no>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

Some codepaths do not still use the ST_[CM]TIME_NSEC() pair of macros
introduced by the previous commit but assumes all systems use st_mtim
and st_ctim fields in "struct stat" to record nanosecond resolution part
of the file timestamps.
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

Traditionally, the lack of USE_NSEC meant "do not record nor use the
nanosecond resolution part of the file timestamps".  To avoid problems on
filesystems that lose the ns part when the metadata is flushed to the disk
and then later read back in, disabling USE_NSEC has been a good idea in
general.

If you are on a filesystem without such an issue, it does not hurt to read
and store them in the cached stat data in the index entries even if your
git is compiled without USE_NSEC.  The index left with such a version of
git can be read by git compiled with USE_NSEC and it can make use of the
nanosecond part to optimize the check to see if the path on the filesystem
hsa been modified since we last looked at.
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

Since this timestamp is used to check for racy-clean files, it is
important to keep it uptodate.

For the 'git checkout' command without the '-q' option, this make a
huge difference.  Before, each and every file which was updated, was
racy-clean after the call to unpack_trees() and write_index() but
before the GIT process ended.

And because of the call to show_local_changes() in builtin-checkout.c,
we ended up reading those files back into memory, doing a SHA1 to
check if the files was really different from the index.  And, of
course, no file was different.

With this fix, 'git checkout' without the '-q' option should now be
almost as fast as with the '-q' option, but not quite, as we still do
some few lstat(2) calls more without the '-q' option.

Below is some average numbers for 10 checkout's to v2.6.27 and 10 to
v2.6.25 of the Linux kernel, to show the difference:

before (git version 1.6.2.rc1.256.g58a87):
 7.860 user  2.427 sys  19.465 real  52.8% CPU  faults: 0 major 95331 minor
after:
 6.184 user  2.160 sys  17.619 real  47.4% CPU  faults: 0 major 38994 minor
Signed-off-by: NKjetil Barvik <barvik@broadpark.no>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

Since the filesystem ext4 is now defined as stable in Linux v2.6.28,
and ext4 supports nanonsecond resolution timestamps natively, it is
time to make USE_NSEC work as expected.

This will make racy git situations less likely to happen.  For 'git
checkout' this means it will be less likely that we have to open, read
the contents of the file into RAM, and check if file is really
modified or not.  The result sould be a litle less used CPU time, less
pagefaults and a litle faster program, at least for 'git checkout'.

Since the number of possible racy git situations would increase when
disks gets faster, this patch would be more and more helpfull as times
go by.  For a fast Solid State Disk, this patch should be helpfull.

Note that, when file operations starts to take less than 1 nanosecond,
one would again start to get more racy git situations.

For more info on racy git, see Documentation/technical/racy-git.txt
For more info on ext4, see http://kernelnewbies.org/Ext4Signed-off-by: NKjetil Barvik <barvik@broadpark.no>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

Below is oprofile output from GIT command 'git chekcout -q my-v2.6.25'
(move from tag v2.6.27 to tag v2.6.25 of the Linux kernel):

CPU: Core 2, speed 1999.95 MHz (estimated)
Counted CPU_CLK_UNHALTED events (Clock cycles when not halted) with a unit
                         mask of 0x00 (Unhalted core cycles) count 20000
Counted INST_RETIRED_ANY_P events (number of instructions retired) with a
                           unit mask of 0x00 (No unit mask) count 20000
CPU_CLK_UNHALT...|INST_RETIRED:2...|
  samples|      %|  samples|      %|
------------------------------------
   409247 100.000    342878 100.000 git
        CPU_CLK_UNHALT...|INST_RETIRED:2...|
          samples|      %|  samples|      %|
        ------------------------------------
           260476 63.6476    257843 75.1996 libz.so.1.2.3
           100876 24.6492     64378 18.7758 kernel-2.6.28.4_2.vmlinux
            30850  7.5382      7874  2.2964 libc-2.9.so
            14775  3.6103      8390  2.4469 git
             2020  0.4936      4325  1.2614 libcrypto.so.0.9.8
              191  0.0467        32  0.0093 libpthread-2.9.so
               58  0.0142        36  0.0105 ld-2.9.so
                1 2.4e-04         0       0 libldap-2.3.so.0.2.31

Detail list of the top 20 function entries (libz counted in one blob):

CPU_CLK_UNHALTED  INST_RETIRED_ANY_P
samples  %        samples  %        image name               symbol name
260476   63.6862  257843   75.2725  libz.so.1.2.3            /lib/libz.so.1.2.3
16587     4.0555  3636      1.0615  libc-2.9.so              memcpy
7710      1.8851  277       0.0809  libc-2.9.so              memmove
3679      0.8995  1108      0.3235  kernel-2.6.28.4_2.vmlinux d_validate
3546      0.8670  2607      0.7611  kernel-2.6.28.4_2.vmlinux __getblk
3174      0.7760  1813      0.5293  libc-2.9.so              _int_malloc
2396      0.5858  3681      1.0746  kernel-2.6.28.4_2.vmlinux copy_to_user
2270      0.5550  2528      0.7380  kernel-2.6.28.4_2.vmlinux __link_path_walk
2205      0.5391  1797      0.5246  kernel-2.6.28.4_2.vmlinux ext4_mark_iloc_dirty
2103      0.5142  1203      0.3512  kernel-2.6.28.4_2.vmlinux find_first_zero_bit
2077      0.5078  997       0.2911  kernel-2.6.28.4_2.vmlinux do_get_write_access
2070      0.5061  514       0.1501  git                      cache_name_compare
2043      0.4995  1501      0.4382  kernel-2.6.28.4_2.vmlinux rcu_irq_exit
2022      0.4944  1732      0.5056  kernel-2.6.28.4_2.vmlinux __ext4_get_inode_loc
2020      0.4939  4325      1.2626  libcrypto.so.0.9.8       /usr/lib/libcrypto.so.0.9.8
1965      0.4804  1384      0.4040  git                      patch_delta
1708      0.4176  984       0.2873  kernel-2.6.28.4_2.vmlinux rcu_sched_grace_period
1682      0.4112  727       0.2122  kernel-2.6.28.4_2.vmlinux sysfs_slab_alias
1659      0.4056  290       0.0847  git                      find_pack_entry_one
1480      0.3619  1307      0.3816  kernel-2.6.28.4_2.vmlinux ext4_writepage_trans_blocks

Notice the memmove line, where the CPU did 7710 / 277 = 27.8 cycles
per instruction, and compared to the total cycles spent inside the
source code of GIT for this command, all the memmove() calls
translates to (7710 * 100) / 14775 = 52.2% of this.

Retesting with a GIT program compiled for gcov usage, I found out that
the memmove() calls came from remove_index_entry_at() in read-cache.c,
where we have:

        memmove(istate->cache + pos,
                istate->cache + pos + 1,
                (istate->cache_nr - pos) * sizeof(struct cache_entry *));

remove_index_entry_at() is called 4902 times from check_updates() in
unpack-trees.c, and each time called we move each cache_entry pointers
(from the removed one) one step to the left.

Since we have 28828 entries in the cache this time, and if we on
average move half of them each time, we in total move approximately
4902 * 0.5 * 28828 * 4 = 282 629 712 bytes, or twice this amount if
each pointer is 8 bytes (64 bit).

OK, is seems that the function check_updates() is called 28 times, so
the estimated guess above had been more correct if check_updates() had
been called only once, but the point is: we get lots of bytes moved.

To fix this, and use an O(N) algorithm instead, where N is the number
of cache_entries, we delete/remove all entries in one loop through all
entries.

From a retest, the new remove_marked_cache_entries() from the patch
below, ended up with the following output line from oprofile:

46        0.0105  15        0.0041  git                      remove_marked_cache_entries

If we can trust the numbers from oprofile in this case, we saved
approximately ((7710 - 46) * 20000) / (2 * 1000 * 1000 * 1000) = 0.077
seconds CPU time with this fix for this particular test.  And notice
that now the CPU did only 46 / 15 = 3.1 cycles/instruction.
Signed-off-by: NKjetil Barvik <barvik@broadpark.no>
Acked-by: NLinus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

After you resolve a conflicted merge to remove the path, "git add -u"
failed to record the removal.  Instead it errored out by saying that the
removed path is not found in the work tree, but that is what the user
already knows, and the wanted to record the removal as the resolution,
so the error does not make sense.
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

This simplifies the code, and also makes ce_compare_link now able to
handle filesystems with odd 'st_size' return values for symlinks.
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

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

Writing a tree out of an index with an "intent to add" entry is blocked.
This implies that you cannot "git commit" from such a state; however you
can still do "git commit -a" or "git commit $that_path".
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

This uses the extended index flag mechanism introduced earlier to mark
the entries added to the index via "git add -N" with CE_INTENT_TO_ADD.

The logic to detect an "intent to add" entry for the purpose of allowing
"git rm --cached $path" is tightened to check not just for a staged empty
blob, but with the CE_INTENT_TO_ADD bit.  This protects an empty blob that
was explicitly added and then modified in the work tree from being dropped
with this sequence:

	$ >empty
	$ git add empty
	$ echo "non empty" >empty
	$ git rm --cached empty
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

Earlier commit 55218834 (checkout: do not lose staged removal, 2008-09-07)
tightened the rule to prevent switching branches from losing local
changes, so that staged removal of paths can be protected, while
attempting to keep a loophole to still allow a special case of switching
out of an un-checked-out state.

However, the loophole was made a bit too tight, and did not allow
switching from one branch (in an un-checked-out state) to check out
another branch.

The change to builtin-checkout.c in this commit loosens it to allow this,
by not insisting the original commit and the new commit to be the same.

It also introduces a new function, is_index_unborn (and an associated
macro, is_cache_unborn), to check if the repository is truly in an
un-checked-out state more reliably, by making sure that $GIT_INDEX_FILE
did not exist when populating the in-core index structure.  A few places
the earlier commit 55218834 added the check for the initial checkout
condition are updated to use this function.
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

If a file is different between the working tree copy, the index, and the
HEAD, then we do not allow it to be deleted without --force.

However, this is overly tight in the face of "git add --intent-to-add":

  $ git add --intent-to-add file
  $ : oops, I don't actually want to stage that yet
  $ git rm --cached file
  error: 'empty' has staged content different from both the
  file and the HEAD (use -f to force removal)
  $ git rm -f --cached file

Unfortunately, there is currently no way to distinguish between an empty
file that has been added and an "intent to add" file. The ideal behavior
would be to disallow the former while allowing the latter.

This patch loosens the safety valve to allow the deletion only if we are
deleting the cached entry and the cached content is empty.  This covers
the intent-to-add situation, and assumes there is little harm in not
protecting users who have legitimately added an empty file.  In many
cases, the file will still be empty, in which case the safety valve does
not trigger anyway (since the content remains untouched in the working
tree). Otherwise, we do remove the fact that no content was staged, but
given that the content is by definition empty, it is not terribly
difficult for a user to recreate it.

However, we still document the desired behavior in the form of two
tests. One checks the correct removal of an intent-to-add file. The other
checks that we still disallow removal of empty files, but is marked as
expect_failure to indicate this compromise. If the intent-to-add feature
is ever extended to differentiate between normal empty files and
intent-to-add files, then the safety valve can be re-tightened.
Signed-off-by: NJeff King <peff@peff.net>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

When aborting a failed merge that has brought in a new path using "git
reset --hard" or "git read-tree --reset -u", we used to first forget about
the new path (via read_cache_unmerged) and then matched the working tree
to what is recorded in the index, thus ending up leaving the new path in
the work tree.
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

When the "git status" display code was originally converted
to C, we copied the code from ls-files to discover whether a
pathname returned by read_directory was an "other", or
untracked, file.

Much later, 5698454e updated the code in ls-files to handle
some new cases caused by gitlinks.  This left the code in
wt-status.c broken: it would display submodule directories
as untracked directories. Nobody noticed until now, however,
because unless status.showUntrackedFiles was set to "all",
submodule directories were not actually reported by
read_directory. So the bug was only triggered in the
presence of a submodule _and_ this config option.

This patch pulls the ls-files code into a new function,
cache_name_is_other, and uses it in both places. This should
leave the ls-files functionality the same and fix the bug
in status.
Signed-off-by: NJeff King <peff@peff.net>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

The on-disk format of index only saves 16 bit flags, nearly all have
been used. The last bit (CE_EXTENDED) is used to for future extension.

This patch extends index entry format to save more flags in future.
The new entry format will be used when CE_EXTENDED bit is 1.

Because older implementation may not understand CE_EXTENDED bit and
misread the new format, if there is any extended entry in index, index
header version will turn 3, which makes it incompatible for older git.
If there is none, header version will return to 2 again.
Signed-off-by: NNguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: NShawn O. Pearce <spearce@spearce.org>

Many call sites use strbuf_init(&foo, 0) to initialize local
strbuf variable "foo" which has not been accessed since its
declaration. These can be replaced with a static initialization
using the STRBUF_INIT macro which is just as readable, saves a
function call, and takes up fewer lines.
Signed-off-by: NBrandon Casey <casey@nrlssc.navy.mil>
Signed-off-by: NShawn O. Pearce <spearce@spearce.org>

If verification of path failed, it is always better to print an
error message saying this than relying on the caller function to
print a meaningful error message (especially when the callee already
prints error message for another situation).

Because the callers of add_index_entry_with_check() did not print
any error message, it resulted that the user would not notice the
problem when checkout of an invalid path failed.
Signed-off-by: NDmitry Potapov <dpotapov@gmail.com>
Signed-off-by: NShawn O. Pearce <spearce@spearce.org>

On ARM I have the following compilation errors:

    CC fast-import.o
In file included from cache.h:8,
                 from builtin.h:6,
                 from fast-import.c:142:
arm/sha1.h:14: error: conflicting types for 'SHA_CTX'
/usr/include/openssl/sha.h:105: error: previous declaration of 'SHA_CTX' was here
arm/sha1.h:16: error: conflicting types for 'SHA1_Init'
/usr/include/openssl/sha.h:115: error: previous declaration of 'SHA1_Init' was here
arm/sha1.h:17: error: conflicting types for 'SHA1_Update'
/usr/include/openssl/sha.h:116: error: previous declaration of 'SHA1_Update' was here
arm/sha1.h:18: error: conflicting types for 'SHA1_Final'
/usr/include/openssl/sha.h:117: error: previous declaration of 'SHA1_Final' was here
make: *** [fast-import.o] Error 1

This is because openssl header files are always included in
git-compat-util.h since commit 684ec6c6 whenever NO_OPENSSL is not
set, which somehow brings in <openssl/sha1.h> clashing with the custom
ARM version.  Compilation of git is probably broken on PPC too for the
same reason.

Turns out that the only file requiring openssl/ssl.h and openssl/err.h
is imap-send.c.  But only moving those problematic includes there
doesn't solve the issue as it also includes cache.h which brings in the
conflicting local SHA1 header file.

As suggested by Jeff King, the best solution is to rename our references
to SHA1 functions and structure to something git specific, and define those
according to the implementation used.
Signed-off-by: NNicolas Pitre <nico@cam.org>
Signed-off-by: NShawn O. Pearce <spearce@spearce.org>

This adds "--intent-to-add" option to "git add".  This is to let the
system know that you will tell it the final contents to be staged later,
iow, just be aware of the presense of the path with the type of the blob
for now.  It is implemented by staging an empty blob as the content.

With this sequence:

    $ git reset --hard
    $ edit newfile
    $ git add -N newfile
    $ edit newfile oldfile
    $ git diff

the diff will show all changes relative to the current commit.  Then you
can do:

    $ git commit -a ;# commit everything

or

    $ git commit oldfile ;# only oldfile, newfile not yet added

to pretend you are working with an index-free system like CVS.
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

unpack_trees() rebuilds the in-core index from scratch by allocating a new
structure and finishing it off by copying the built one to the final
index.

The resulting in-core index is Ok for most use, but read_cache() does not
recognize it as such.  The function is meant to be no-op if you already
have loaded the index, until you call discard_cache().

This change the way read_cache() detects an already initialized in-core
index, by introducing an extra bit, and marks the handcrafted in-core
index as initialized, to avoid this problem.

A better fix in the longer term would be to change the read_cache() API so
that it will always discard and re-read from the on-disk index to avoid
confusion.  But there are higher level API that have relied on the current
semantics, and they and their users all need to get converted, which is
outside the scope of 'maint' track.

An example of such a higher level API is write_cache_as_tree(), which is
used by git-write-tree as well as later Porcelains like git-merge, revert
and cherry-pick.  In the longer term, we should remove read_cache() from
there and add one to cmd_write_tree(); other callers expect that the
in-core index they prepared is what gets written as a tree so no other
change is necessary for this particular codepath.

The original version of this patch marked the index by pointing an
otherwise wasted malloc'ed memory with o->result.alloc, but this version
uses Linus's idea to use a new "initialized" bit, which is conceptually
much cleaner.
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

We forgot to reset name_hash_initialized bit when discarding the in-core index.
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

We do not have any more bits in the on-disk index flags word, but we would
need to have more in the future.  Use the last remaining bits as a signal
to tell us that the index entry we are looking at is an extended one.

Since we do not understand the extended format yet, we will just error out
when we see it.
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

The ie_modified() function is the workhorse for refresh_cache_entry(),
i.e. checking if an index entry that is stat-dirty actually has changes.

After running quicker check to compare cached stat information with
results from the latest lstat(2) to answer "has modification" early, the
code goes on to check if there really is a change by comparing the staged
data with what is on the filesystem by asking ce_modified_check_fs().
However, this function always said "no change" for any gitlinks that has a
directory at the corresponding path.  This made ie_modified() to miss
actual changes in the subproject.

The patch fixes this first by modifying an existing short-circuit logic
before calling the ce_modified_check_fs() function.  It knows that for any
filesystem entity to which ie_match_stat() says its data has changed, if
its cached size is nonzero then the contents cannot match, which is a
correct optimization only for blob objects.  We teach gitlink objects to
this special case, as we already know that any gitlink that
ie_match_stat() says is modified is indeed modified at this point in the
codepath.

With the above change, we could leave ce_modified_check_fs() broken, but
it also futureproofs the code by teaching it to use ce_compare_gitlink(),
instead of assuming (incorrectly) that any directory is unchanged.

Originally noticed by Alex Riesen on Cygwin.
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

A new configuration variable 'core.trustctime' is introduced to
allow ignoring st_ctime information when checking if paths
in the working tree has changed, because there are situations where
it produces too much false positives.  Like when file system crawlers
keep changing it when scanning and using the ctime for marking scanned
files.

The default is to notice ctime changes.
Signed-off-by: NAlex Riesen <raa.lkml@gmail.com>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>