If user's TMPDIR is insanely long, return negative after
setting errno to ENAMETOOLONG, pretending that the underlying
mkstemp() choked on a temporary file path that is too long.
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

This would hopefully make it easier to maintain.  Initially we
would have "java" and "tex" defined, as they are the only ones
we already have.
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

The code shuffling mistakenly lost binariness specified with the
attribute mecahnism and made it always guess from the data.

Noticed by Johannes, with two test cases to t4020.
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

This updates the hunk header customization syntax.  The special
case 'funcname' attribute is gone.

You assign the name of the type of contents to path's "diff"
attribute as a string value in .gitattributes like this:

	*.java diff=java
	*.perl diff=perl
	*.doc diff=doc

If you supply "diff.<name>.funcname" variable via the
configuration mechanism (e.g. in $HOME/.gitconfig), the value is
used as the regexp set to find the line to use for the hunk
header (the variable is called "funcname" because such a line
typically is the one that has the name of the function in
programming language source text).

If there is no such configuration, built-in default is used, if
any.  Currently there are two default patterns: default and java.
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

This makes"diff -p" hunk headers customizable via gitattributes mechanism.
It is based on Johannes's earlier patch that allowed to define a single
regexp to be used for everything.

The mechanism to arrive at the regexp that is used to define hunk header
is the same as other use of gitattributes.  You assign an attribute, funcname
(because "diff -p" typically uses the name of the function the patch is about
as the hunk header), a simple string value.  This can be one of the names of
built-in pattern (currently, "java" is defined) or a custom pattern name, to
be looked up from the configuration file.

  (in .gitattributes)
  *.java   funcname=java
  *.perl   funcname=perl

  (in .git/config)
  [funcname]
    java = ... # ugly and complicated regexp to override the built-in one.
    perl = ... # another ugly and complicated regexp to define a new one.
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

The instances of xdemitconf_t were initialized member by member.
Instead, initialize them to all zero, so we do not have
to update those places each time we introduce a new member.

[jc: minimally fixed by getting rid of a new global]
Signed-off-by: NJohannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

This replaces an explicit initialization of filespec->is_binary
field used for rename/break followed by direct access to that
field with a wrapper function that lazily iniaitlizes and
accesses the field.  We would add more attribute accesses for
the use of diff routines, and it would be better to make this
abstraction earlier.
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

To prevent funky games with external diff engines, git-log and
friends prevent external diff engines from being called. That makes
sense in the context of git-format-patch or git-rebase.

However, for "git log -p" it is not so nice to get the message
that binary files cannot be compared, while "git diff" has no
problems with them, if you provided an external diff driver.

With this patch, "git log --ext-diff -p" will do what you expect,
and the option "--no-ext-diff" can be used to override that
setting.
Signed-off-by: NJohannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

Without this patch, an added file would be reported as /dev/null.

Noticed by David Kastrup.
Signed-off-by: NJohannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

diffcore-break and diffcore-rename would want to behave slightly
differently depending on the binary-ness of the data, so add one
bit to the filespec, as the structure is now passed down to
diffcore_count_changes() function.
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

Rounding down the printed (dis)similarity index allows us to use
"100%" as a special value that indicates complete rewrites and
fully equal file contents, respectively.
Signed-off-by: NRene Scharfe <rene.scharfe@lsrfire.ath.cx>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

Ok, I've really held off doing this too damn long, because I'm lazy, and I
was always hoping that somebody else would do it.

But no, people keep asking for it, but nobody actually did anything, so I
decided I might as well bite the bullet, and instead of telling people
they could add a "--follow" flag to "git log" to do what they want to do,
I decided that it looks like I just have to do it for them..

The code wasn't actually that complicated, in that the diffstat for this
patch literally says "70 insertions(+), 1 deletions(-)", but I will have
to admit that in order to get to this fairly simple patch, you did have to
know and understand the internal git diff generation machinery pretty
well, and had to really be able to follow how commit generation interacts
with generating patches and generating the log.

So I suspect that while I was right that it wasn't that hard, I might have
been expecting too much of random people - this patch does seem to be
firmly in the core "Linus or Junio" territory.

To make a long story short: I'm sorry for it taking so long until I just
did it.

I'm not going to guarantee that this works for everybody, but you really
can just look at the patch, and after the appropriate appreciative noises
("Ooh, aah") over how clever I am, you can then just notice that the code
itself isn't really that complicated.

All the real new code is in the new "try_to_follow_renames()" function. It
really isn't rocket science: we notice that the pathname we were looking
at went away, so we start a full tree diff and try to see if we can
instead make that pathname be a rename or a copy from some other previous
pathname. And if we can, we just continue, except we show *that*
particular diff, and ever after we use the _previous_ pathname.

One thing to look out for: the "rename detection" is considered to be a
singular event in the _linear_ "git log" output! That's what people want
to do, but I just wanted to point out that this patch is *not* carrying
around a "commit,pathname" kind of pair and it's *not* going to be able to
notice the file coming from multiple *different* files in earlier history.

IOW, if you use "git log --follow", then you get the stupid CVS/SVN kind
of "files have single identities" kind of semantics, and git log will just
pick the identity based on the normal move/copy heuristics _as_if_ the
history could be linearized.

Put another way: I think the model is broken, but given the broken model,
I think this patch does just about as well as you can do. If you have
merges with the same "file" having different filenames over the two
branches, git will just end up picking _one_ of the pathnames at the point
where the newer one goes away. It never looks at multiple pathnames in
parallel.

And if you understood all that, you probably didn't need it explained, and
if you didn't understand the above blathering, it doesn't really mtter to
you. What matters to you is that you can now do

	git log -p --follow builtin-rev-list.c

and it will find the point where the old "rev-list.c" got renamed to
"builtin-rev-list.c" and show it as such.
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

We already have two instances where we want to determine if a buffer
contains binary data as opposed to text.

[jc: cherry-picked 6bfce93e from 'master']
Signed-off-by: NJohannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

Earlier, a second "-C" on the command line had no effect.
But "--find-copies-harder" is so long to type, let's make doubled -C
enable that option.  It is in line with how "git blame" handles such
doubled options to mean "work harder".
Signed-off-by: NJohannes Schindelin <Johannes.Schindelin@gmx.de>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

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

This uses "git-apply --whitespace=strip" to fix whitespace errors that have
crept in to our source files over time.  There are a few files that need
to have trailing whitespaces (most notably, test vectors).  The results
still passes the test, and build result in Documentation/ area is unchanged.
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

We already have two instances where we want to determine if a buffer
contains binary data as opposed to text.
Signed-off-by: NJohannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

Signed-off-by: NJakub Narebski <jnareb@gmail.com>
Signed-off-by: NJunio C Hamano <junkio@cox.net>

Unify naming of plumbing dirlink/gitlink concept:

git ls-files -z '*.[ch]' |
xargs -0 perl -pi -e 's/dirlink/gitlink/g;' -e 's/DIRLNK/GITLINK/g;'
Signed-off-by: NJunio C Hamano <junkio@cox.net>

Signed-off-by: NFernando J. Pereda <ferdy@gentoo.org>
Signed-off-by: NJunio C Hamano <junkio@cox.net>

This patch fixes all calls to xread() where the return value is not
stored into an ssize_t. The patch should not have any effect whatsoever,
other than putting better/more appropriate type names on variables.
Signed-off-by: NJohan Herland <johan@herland.net>
Signed-off-by: NJunio C Hamano <junkio@cox.net>

diff_filespec has a slot to record the size of the data already,
so make use of it instead of a separate size cache.
Signed-off-by: NJunio C Hamano <junkio@cox.net>

This reduces the memory pressure when dealing with many paths.

An unscientific test of running "diff-tree --stat --summary -M"
between v2.6.19 and v2.6.20-rc1 in the linux kernel repository
indicates that the number of minor faults are reduced by 2/3.
Signed-off-by: NJunio C Hamano <junkio@cox.net>

We broke the size-cache handling when we changed the function
signature of sha1_object_info() in 21666f1a.  We obviously
wanted to cache the size we obtained when sha1_object_info()
succeeded, not when it failed.
Signed-off-by: NJunio C Hamano <junkio@cox.net>

This enhances the attributes mechanism so that external programs
meant for existing GIT_EXTERNAL_DIFF interface can be specifed
per path.

To configure such a custom diff driver, first define a custom
diff driver in the configuration:

	[diff "my-c-diff"]
		command = <<your command string comes here>>

Then mark the paths that you want to use this custom driver
using the attribute mechanism.

	*.c	diff=my-c-diff

The intent of this separation is that the attribute mechanism is
used for specifying the type of the contents, while the
configuration mechanism is used to define what needs to be done
to that type of the contents, which would be specific to both
platform and personal taste.
Signed-off-by: NJunio C Hamano <junkio@cox.net>

Signed-off-by: NAlex Riesen <raa.lkml@gmail.com>
Signed-off-by: NJunio C Hamano <junkio@cox.net>

It was bothering me a lot that I abused small integer values
casted to (void *) to represent non string values in
gitattributes.  This corrects it by making the type of attribute
values (const char *), and using the address of a few statically
allocated character buffer to denote true/false.  Unset attributes
are represented as having NULLs as their values.

Added in-header documentation to explain how git_checkattr()
routine should be called.
Signed-off-by: NJunio C Hamano <junkio@cox.net>

This allows you to define three values (and possibly more) to
each attribute: true, false, and unset.

Typically the handlers that notice and act on attribute values
treat "unset" attribute to mean "do your default thing"
(e.g. crlf that is unset would trigger "guess from contents"),
so being able to override a setting to an unset state is
actually useful.

 - If you want to set the attribute value to true, have an entry
   in .gitattributes file that mentions the attribute name; e.g.

	*.o	binary

 - If you want to set the attribute value explicitly to false,
   use '-'; e.g.

	*.a	-diff

 - If you want to make the attribute value _unset_, perhaps to
   override an earlier entry, use '!'; e.g.

	*.a	-diff
	c.i.a	!diff

This also allows string values to attributes, with the natural
syntax:

	attrname=attrvalue

but you cannot use it, as nobody takes notice and acts on
it yet.
Signed-off-by: NJunio C Hamano <junkio@cox.net>

This is in the same spirit as the previous one.  Earlier 'diff'
meant 'do the built-in binary heuristics and disable patch text
generation based on it' while '!diff' meant 'do not guess, do
not generate patch text'.  There was no way to say 'do generate
patch text even when the heuristics says it has NUL in it'.
Signed-off-by: NJunio C Hamano <junkio@cox.net>

The same way we generate diffs on symlinks as the the diff of text of the
symlink, we can generate subproject diffs (when not recursing into them!)
as the diff of the text that describes the subproject.

Of course, since what descibes a subproject is just the SHA1, that's what
we'll use. Add some pretty-printing to make it a bit more obvious what is
going on, and we're done.

So with this, we can get both raw diffs and "textual" diffs of subproject
changes:

 - git diff --raw:

	:160000 160000 2de597b5ad348b7db04bd10cdd38cd81cbc93ab5 0000000... M    sub-A

 - git diff:

	diff --git a/sub-A b/sub-A
	index 2de597b..e8f11a4 160000
	--- a/sub-A
	+++ b/sub-A
	@@ -1 +1 @@
	-Subproject commit 2de597b5ad348b7db04bd10cdd38cd81cbc93ab5
	+Subproject commit e8f11a45c5c6b9e2fec6d136d3fb5aff75393d42

NOTE! We'll also want to have the ability to recurse into the subproject
and actually diff it recursively, but that will involve a new command line
option (I'd suggest "--subproject" and "-S", but the latter is in use by
pickaxe), and some very different code.

But regardless of ay future recursive behaviour, we need the non-recursive
version too (and it should be the default, at least in the absense of
config options, so that large superprojects don't default to something
extremely expensive).
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: NJunio C Hamano <junkio@cox.net>

This makes paths that explicitly unset 'diff' attribute not to
produce "textual" diffs from 'git-diff' family.
Signed-off-by: NJunio C Hamano <junkio@cox.net>

Previously, a binary file in the diffstat would show as:

 some-binary-file.bin       |  Bin

The space after the "Bin" was never used.  This patch changes binary
lines in the diffstat to be:

 some-binary-file.bin       |  Bin 12345 -> 123456 bytes

The very nice "->" notation was suggested by Johannes Schindelin, and
shows the before and after sizes more clearly than "+" and "-" would.
If a size is 0 it's not shown (although it would probably be better to
treat no-file differently from zero-byte-file).

The user can see what changed in the binary file, and how big the new
file is.  This is in keeping with the information in the rest of the
diffstat.

The diffstat_t members "added" and "deleted" were unused when the file
was binary, so this patch loads them with the file sizes in
builtin_diffstat().  These figures are then read in show_stats() when
the file is marked binary.
Signed-off-by: NAndy Parkins <andyparkins@gmail.com>
Signed-off-by: NJunio C Hamano <junkio@cox.net>

This adds the command line option 'quiet' to tell 'git diff-*'
that we are not interested in the actual diff contents but only
want to know if there is any change.  This option automatically
turns --exit-code on, and turns off output formatting, as it
does not make much sense to show the first hit we happened to
have found.

The --quiet option is silently turned off (but --exit-code is
still in effect, so is silent output) if postprocessing filters
such as pickaxe and diff-filter are used.  For all practical
purposes I do not think of a reason to want to use these filters
and not viewing the diff output.

The backends have not been taught about the option with this patch.
That is a topic for later rounds.
Signed-off-by: NJunio C Hamano <junkio@cox.net>

This was only used by diff-tree-helper program, whose purpose
was to translate a raw diff to a patch.
Signed-off-by: NJunio C Hamano <junkio@cox.net>

This introduces a new command-line option: --exit-code. The diff
programs will return 1 for differences, return 0 for equality, and
something else for errors.
Signed-off-by: NAlex Riesen <raa.lkml@gmail.com>
Signed-off-by: NJunio C Hamano <junkio@cox.net>

Some systems have sizeof(off_t) == 8 while sizeof(size_t) == 4.
This implies that we are able to access and work on files whose
maximum length is around 2^63-1 bytes, but we can only malloc or
mmap somewhat less than 2^32-1 bytes of memory.

On such a system an implicit conversion of off_t to size_t can cause
the size_t to wrap, resulting in unexpected and exciting behavior.
Right now we are working around all gcc warnings generated by the
-Wshorten-64-to-32 option by passing the off_t through xsize_t().

In the future we should make xsize_t on such problematic platforms
detect the wrapping and die if such a file is accessed.
Signed-off-by: NShawn O. Pearce <spearce@spearce.org>
Signed-off-by: NJunio C Hamano <junkio@cox.net>

The earlier commit to read from stdin was full of problems, and
this corrects them.

 - The mode bits should have been set to satisify S_ISREG(); we
   forgot to the S_IFREG bits and hardcoded 0644;
 - We did not give escape hatch to name a path whose name is
   really "-".  Allow users to say "./-" for that;
 - Use of xread() was not prepared to see short read (e.g. reading
   from tty) nor handing read errors.
Signed-off-by: NJunio C Hamano <junkio@cox.net>

This allows you to say

	echo Hello World | git diff x -

to compare the contents of file "x" with the line "Hello World".
This automatically switches to --no-index mode.
Signed-off-by: NJohannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: NJunio C Hamano <junkio@cox.net>

We currently have two parallel notation for dealing with object types
in the code: a string and a numerical value.  One of them is obviously
redundent, and the most used one requires more stack space and a bunch
of strcmp() all over the place.

This is an initial step for the removal of the version using a char array
found in object reading code paths.  The patch is unfortunately large but
there is no sane way to split it in smaller parts without breaking the
system.
Signed-off-by: NNicolas Pitre <nico@cam.org>
Signed-off-by: NJunio C Hamano <junkio@cox.net>

diff sets the exit status to 0 when no changes were found, to 1
when changes were found, and 2 means error.

We imitate this to be able to use "git diff" in the test scripts.
(Actually, keeping in line with the rest of git, -1 is returned
on error, which corresponds to an exit status 255).

To find out if the diff is not empty, a member called
"found_changes" was introduced in struct diff_options, which is
set in builtin_diff() and fn_out_consume().
Signed-off-by: NJohannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: NJunio C Hamano <junkio@cox.net>