Actually, it is a diff option now, so you can say

	git diff --check

to ask if what you are about to commit is a good patch.

[jc: this also would work for fmt-patch, but the point is that
 the check is done before making a commit.  format-patch is run
 from an already created commit, and that is too late to catch
 whitespace damaged change.]
Signed-off-by: NJohannes Schindelin <Johannes.Schindelin@gmx.de>
Signed-off-by: NJunio C Hamano <junkio@cox.net>

Remove the need to pipe git diff through git apply to
get the extended headers summary.
Signed-off-by: NSean Estabrooks <seanlkml@sympatico.ca>
Signed-off-by: NJunio C Hamano <junkio@cox.net>

We used to parse "-U" and "--unified" as part of the GIT_DIFF_OPTS
environment variable, but strangely enough we would _not_ parse them as
part of the normal diff command line (where we only accepted "-u").

This adds parsing of -U and --unified, both with an optional numeric
argument. So now you can just say

	git diff --unified=5

to get a unified diff with a five-line context, instead of having to do
something silly like

	GIT_DIFF_OPTS="--unified=5" git diff -u

(that silly format does continue to still work, of course).
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>
Signed-off-by: NJunio C Hamano <junkio@cox.net>

This updates the user interface and generated diff data format.

 * "diff --binary" is used to signal that we want an e-mailable
   binary patch.  It implies --full-index and -p.

 * "apply --allow-binary-replacement" acquired a short synonym
   "apply --binary".

 * After the "GIT binary patch\n" header line there is a token
   to record which binary patch mechanism was used, so that we
   can extend it later.  Currently there are two mechanisms
   defined: "literal" and "delta".  The former records the
   deflated postimage and the latter records the deflated delta
   from the preimage to postimage.

   For purely implementation convenience, I added the deflated
   length after these "literal/delta" tokens (otherwise the
   decoding side needs to guess and reallocate the buffer while
   inflating).  Improvement patches are very welcomed.
Signed-off-by: NJunio C Hamano <junkio@cox.net>

"git diff(n)" without --base, --ours, etc. defaults to --cc,
which usually is the same as -p unless you are in the middle of
a conflicted merge, just like the shell script version.

"git diff(n) blobA blobB path" complains and dies.

"git diff(n) tree0 tree1 tree2...treeN" does combined diff that
shows a merge of tree1..treeN to result in tree0.

Giving "-c" option to any command that defaults to "--cc" turns
off dense-combined flag.
Signed-off-by: NJunio C Hamano <junkio@cox.net>

"diff-index -m" does not mean "do not ignore merges", but means
"pretend missing files match the index".

The previous round tried to address this, but failed because
setup_revisions() ate "-m" flag before the caller had a chance
to intervene.
Signed-off-by: NJunio C Hamano <junkio@cox.net>

The second installment to libify diff brothers.  The pathname
arguments are checked more strictly than before because we now
use the revision.c::setup_revisions() infrastructure.
Signed-off-by: NJunio C Hamano <junkio@cox.net>

This is the first installment to libify diff brothers.

The updated diff-files uses revision.c::setup_revisions()
infrastructure to parse its command line arguments, which means
the pathname arguments are checked more strictly than before.
The tests are adjusted to separate possibly missing paths from
the rest of arguments with double-dashes, to show the kosher
way.

As Linus pointed out, renaming diff.c to diff-lib.c was simply
stupid, so I am renaming it back.  The new diff-lib.c is to
contain pieces extracted from diff brothers.
Signed-off-by: NJunio C Hamano <junkio@cox.net>

On Sun, 16 Apr 2006, Junio C Hamano wrote:
>
> In the mid-term, I am hoping we can drop the generate_header()
> callchain _and_ the custom code that formats commit log in-core,
> found in cmd_log_wc().

Ok, this was nastier than expected, just because the dependencies between
the different log-printing stuff were absolutely _everywhere_, but here's
a patch that does exactly that.

The patch is not very easy to read, and the "--patch-with-stat" thing is
still broken (it does not call the "show_log()" thing properly for
merges). That's not a new bug. In the new world order it _should_ do
something like

	if (rev->logopt)
		show_log(rev, rev->logopt, "---\n");

but it doesn't. I haven't looked at the --with-stat logic, so I left it
alone.

That said, this patch removes more lines than it adds, and in particular,
the "cmd_log_wc()" loop is now a very clean:

	while ((commit = get_revision(rev)) != NULL) {
		log_tree_commit(rev, commit);
		free(commit->buffer);
		commit->buffer = NULL;
	}

so it doesn't get much prettier than this. All the complexity is entirely
hidden in log-tree.c, and any code that needs to flush the log literally
just needs to do the "if (rev->logopt) show_log(...)" incantation.

I had to make the combined_diff() logic take a "struct rev_info" instead
of just a "struct diff_options", but that part is pretty clean.

This does change "git whatchanged" from using "diff-tree" as the commit
descriptor to "commit", and I changed one of the tests to reflect that new
reality. Otherwise everything still passes, and my other tests look fine
too.
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>
Signed-off-by: NJunio C Hamano <junkio@cox.net>

With this option, git prepends a diffstat in front of the patch.

Since I really, really do not know what a diffstat of a combined diff
("merge diff") should look like, the diffstat is not generated for these.
Signed-off-by: NJohannes Schindelin <Johannes.Schindelin@gmx.de>
Signed-off-by: NJunio C Hamano <junkio@cox.net>

Now, you can say "git diff --stat" (to get an idea how many changes are
uncommitted), or "git log --stat".
Signed-off-by: NJohannes Schindelin <Johannes.Schindelin@gmx.de>
Signed-off-by: NJunio C Hamano <junkio@cox.net>

Signed-off-by: NPetr Baudis <pasky@suse.cz>
Signed-off-by: NJunio C Hamano <junkio@cox.net>

This new flag outputs the diff-raw output and diff-patch output
at the same time.  Requested by Cogito.
Signed-off-by: NJunio C Hamano <junkio@cox.net>

The way tree-diff was set up assumed we would use only one set
of pathspec during the entire life of the program.  Move the
pathspec related static variables out to diff_options structure
so that we can filter commits with one set of paths while show
the actual diffs using different set of paths.

I suspect this breaks blame.c, and makes "git log paths..." to
default to the --full-diff, the latter of which is dealt with
the next commit.
Signed-off-by: NJunio C Hamano <junkio@cox.net>

Nobody except diff-stages used it -- the callers instead filtered
the input to diffcore themselves.  Make diff-stages do that as
well and retire diffcore-pathspec.
Signed-off-by: NJunio C Hamano <junkio@cox.net>

git-diff-* --pickaxe-regex will change the -S pickaxe to match
POSIX extended regular expressions instead of fixed strings.

The regex.h library is a rather stupid interface and I like pcre too, but
with any luck it will be everywhere we will want to run Git on, it being
POSIX.2 and all. I'm not sure if we can expect platforms like AIX to
conform to POSIX.2 or if win32 has regex.h. We might add a flag to
Makefile if there is a portability trouble potential.
Signed-off-by: NPetr Baudis <pasky@suse.cz>

Introduce tree-walk.[ch] and move "struct tree_desc" and
associated functions from various places.

Rename DIFF_FILE_CANON_MODE(mode) macro to canon_mode(mode) and
move it to cache.h.  This macro returns the canonicalized
st_mode value in the host byte order for files, symlinks and
directories -- to be compared with a tree_desc entry.
create_ce_mode(mode) in cache.h is similar but is intended to be
used for index entries (so it does not work for directories) and
returns the value in the network byte order.
Signed-off-by: NJunio C Hamano <junkio@cox.net>

This shows "new file mode XXXX" and "deleted file mode XXXX"
lines like two-way diff-patch output does, by checking the
status from each parent.

The diff-raw output for combined diff is made a bit uglier by
showing diff status letters with each parent.  While most of the
case you would see "MM" in the output, an Evil Merge that
touches a path that was added by inheriting from one parent is
possible and it would be shown like these:

    $ git-diff-tree --abbrev -c HEAD
    2d7ca89675eb8888b0b88a91102f096d4471f09f
    ::000000 000000 100644 0000000... 0000000... 31dd686... AA	b
    ::000000 100644 100644 0000000... 6c884ae... c6d4fa8... AM	d
    ::100644 100644 100644 4f7cbe7... f8c295c... 19d5d80... RR	e
Signed-off-by: NJunio C Hamano <junkio@cox.net>

This way, diff-files can make use of it.  Also implement the
full suite of what diff_flush_raw() supports just for
consistency.  With this, 'diff-tree -c -r --name-status' would
show what is expected.

There is no way to get the historical output (useful for
debugging and low-level Plumbing work) anymore, so tentatively
it makes '-m' to mean "do not combine and show individual diffs
with parents".

diff-files matches diff-tree to produce raw output for -c.  For
textual combined diff, use -p -c.
Signed-off-by: NJunio C Hamano <junkio@cox.net>

NOTE! This makes "-c" be the default, which effectively means that merges 
are never ignored any more, and "-m" is a no-op. So it changes semantics.

I would also like to make "--cc" the default if you do patches, but didn't 
actually do that.

The raw output format is not wonderfully pretty, but it's distinguishable 
from a "normal patch" in that a normal patch with just one parent has just 
one colon at the beginning, while a multi-parent raw diff has <n> colons 
for <n> parents.

So now, in the kernel, when you do

	git-diff-tree cce0cac125623f9b68f25dd1350f6d616220a8dd

(to see the manual ARM merge that had a conflict in arch/arm/Kconfig), you 
get

	cce0cac125623f9b68f25dd1350f6d616220a8dd
	::100644 100644 100644 4a63a8e2e45247a11c068c6ed66c6e7aba29ddd9 77eee38762d69d3de95ae45dd9278df9b8225e2c 2f61726d2f4b636f6e66696700dbf71a59dad287       arch/arm/Kconfig

ie you see two colons (two parents), then three modes (parent modes 
followed by result mode), then three sha1s (parent sha1s followed by
result sha1).

Which is pretty close to the normal raw diff output.

Cool/stupid exercise:

	$ git-whatchanged | grep '^::' | cut -f2- | sort |
	  uniq -c | sort -n | less -S

will show which files have needed the most file-level merge conflict
resolution. Useful? Probably not. But kind of interesting.

For the kernel, it's

     ....
     10 arch/ia64/Kconfig
     11 drivers/scsi/Kconfig
     12 drivers/net/Makefile
     17 include/linux/libata.h
     18 include/linux/pci_ids.h
     23 drivers/net/Kconfig
     24 drivers/scsi/libata-scsi.c
     28 drivers/scsi/libata-core.c
     43 MAINTAINERS
Signed-off-by: NJunio C Hamano <junkio@cox.net>

Signed-off-by: NJunio C Hamano <junkio@cox.net>

Now --always flag is available in diff-tree, there is no reason
to have that hack in the diffcore side.
Signed-off-by: NJunio C Hamano <junkio@cox.net>

We have operations to "extract" and "update" a "struct tree_desc", but we
only used them in tree-diff.c and they were static to that file.

But other tree traversal functions can use them to their advantage
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>
Signed-off-by: NJunio C Hamano <junkio@cox.net>

The minimum length of abbreviated object name was hardcoded in
different places to be 4, risking inconsistencies in the future.
Also there were three different "default abbreviation
precision".  Use two C preprocessor symbols to clean up this
mess.
Signed-off-by: NJunio C Hamano <junkio@cox.net>

This ports the "combined diff" to diff-files so that differences
to the working tree files since stage 2 and stage 3 are shown
the same way as combined diff output from diff-tree for the
merge commit would be shown if the current working tree files
are committed.
Signed-off-by: NJunio C Hamano <junkio@cox.net>

Building on the previous '-c' (combined) option, '--cc' option
squelches the output further by omitting hunks that consist of
difference with solely one parent.
Signed-off-by: NJunio C Hamano <junkio@cox.net>

A new option '-c' to diff-tree changes the way a merge commit is
displayed when generating a patch output.  It shows a "combined
diff" (hence the option letter 'c'), which looks like this:

    $ git-diff-tree --pretty -c -p fec9ebf1 | head -n 18
    diff-tree fec9ebf1... (from parents)
    Merge: 0620db36... 8a263aeb...
    Author: Junio C Hamano <junkio@cox.net>
    Date:   Sun Jan 15 22:25:35 2006 -0800

	Merge fixes up to GIT 1.1.3

    diff --combined describe.c
    @@@ +98,7 @@@
	    return (a_date > b_date) ? -1 : (a_date == b_date) ? 0 : 1;
       }

    -  static void describe(char *arg)
     - static void describe(struct commit *cmit, int last_one)
    ++ static void describe(char *arg, int last_one)
       {
     +      unsigned char sha1[20];
     +      struct commit *cmit;

There are a few things to note about this feature:

 - The '-c' option implies '-p'.  It also implies '-m' halfway
   in the sense that "interesting" merges are shown, but not all
   merges.

 - When a blob matches one of the parents, we do not show a diff
   for that path at all.  For a merge commit, this option shows
   paths with real file-level merge (aka "interesting things").

 - As a concequence of the above, an "uninteresting" merge is
   not shown at all.  You can use '-m' in addition to '-c' to
   show the commit log for such a merge, but there will be no
   combined diff output.

 - Unlike "gitk", the output is monochrome.

A '-' character in the nth column means the line is from the nth
parent and does not appear in the merge result (i.e. removed
from that parent's version).

A '+' character in the nth column means the line appears in the
merge result, and the nth parent does not have that line
(i.e. added by the merge itself or inherited from another
parent).

The above example output shows that the function signature was
changed from either parents (hence two "-" lines and a "++"
line), and "unsigned char sha1[20]", prefixed by a " +", was
inherited from the first parent.

The code as sent to the list was buggy in few corner cases,
which I have fixed since then.

It does not bother to keep track of and show the line numbers
from parent commits, which it probably should.
Signed-off-by: NJunio C Hamano <junkio@cox.net>

It was implemented there but was not advertised.
Signed-off-by: NJunio C Hamano <junkio@cox.net>

When I show transcripts to explain how something works, I often
find myself hand-editing the diff-raw output to shorten various
object names in the output.

This adds --abbrev option to the diff family, which shortens
diff-raw output and diff-tree commit id headers.
Signed-off-by: NJunio C Hamano <junkio@cox.net>

Otherwise we would end up linking all the unneeded stuff into git-daemon
only to link with git_default_config.
Signed-off-by: NJunio C Hamano <junkio@cox.net>

Signed-off-by: NJunio C Hamano <junkio@cox.net>

A new option, --full-index, is introduced to diff family.  This
causes the full object name of pre- and post-images to appear on
the index line of patch formatted output, to be used in
conjunction with --allow-binary-replacement option of git-apply.
Signed-off-by: NJunio C Hamano <junkio@cox.net>

Update docs and usages regarding '-r' recursive option for git-diff-tree.
Remove '-r' from common diff options, mention it only for git-diff-tree.
Remove one extraneous use of '-r' with git-diff-files in get-merge.sh.
Sync the synopsis and usage string for git-diff-tree.

Signed-off-by: Chris Shoemaker <c.shoemaker at cox.net>
Signed-off-by: NJunio C Hamano <junkio@cox.net>

This makes the tree diff functionality independent of the "git-diff-tree"
program, by splitting the core functionality up into a library file.

This will be needed for when we teach git-rev-list to only follow a
specified set of pathnames, rather than the global revision history.

Most of it is a fairly straightforward code move, but it also involves
some calling convention cleanup, and moving some of the static variables
from diff-tree.c into the options structure.

The actual tree change callback routines also become paramterized by the
diff_options structure, allowing the library functionality to do something
else than just show the diff on stdout.

Right now the only user of this functionality remains git-diff-tree
itself.
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>
Signed-off-by: NJunio C Hamano <junkio@cox.net>

When we updated the marker for new files from 'N' to 'A', we forgot to
notice that the letter is already taken by the All-Or-None mark.
Change the All-Or-None marker to '*' to resolve this conflict.

	git-diff-tree -r --diff-filter='R*' -M

shows all the changes (not just renames) that are contained in commits
that have renames, in comparison with:

	git-diff-tree -r --diff-filter='R' -M

shows the same set of changes but the diff output are limited only to
renaming changes.
Signed-off-by: NJunio C Hamano <junkio@cox.net>

The new output format shows only the status letter and paths.
Signed-off-by: NJunio C Hamano <junkio@cox.net>

When many paths are modified, rename detection takes a lot of time.
The new option -l<num> can be used to disable rename detection when
more than <num> paths are possibly created as renames.
Signed-off-by: NJunio C Hamano <junkio@cox.net>

This is a long overdue clean-up to the code for parsing and passing
diff options.  It also tightens some constness issues.
Signed-off-by: NJunio C Hamano <junkio@cox.net>

The textual diff generation with built-in '-p' in diff-* brothers has
proven to be useful enough that git-diff-helper outlived its usefulness.
Signed-off-by: NJunio C Hamano <junkio@cox.net>

This actually changes the diff-raw status letter from N to A
for added files.
Signed-off-by: NJunio C Hamano <junkio@cox.net>