If our size computation overflows size_t, we may allocate a
much smaller buffer than we expected and overflow it. It's
probably impossible to trigger an overflow in most of these
sites in practice, but it is easy enough convert their
additions and multiplications into overflow-checking
variants. This may be fixing real bugs, and it makes
auditing the code easier.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Using FLEX_ARRAY macros reduces the amount of manual
computation size we have to do. It also ensures we don't
overflow size_t, and it makes sure we write the same number
of bytes that we allocated.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
We frequently allocate strings as xmalloc(len + 1), where
the extra 1 is for the NUL terminator. This can be done more
simply with xmallocz, which also checks for integer
overflow.
There's no case where switching xmalloc(n+1) to xmallocz(n)
is wrong; the result is the same length, and malloc made no
guarantees about what was in the buffer anyway. But in some
cases, we can stop manually placing NUL at the end of the
allocated buffer. But that's only safe if it's clear that
the contents will always fill the buffer.
In each case where this patch does so, I manually examined
the control flow, and I tried to err on the side of caution.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Each of these cases can be converted to use ALLOC_ARRAY or
REALLOC_ARRAY, which has two advantages:
1. It automatically checks the array-size multiplication
for overflow.
2. It always uses sizeof(*array) for the element-size,
so that it can never go out of sync with the declared
type of the array.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Convert all instances of get_object_hash to use an appropriate reference
to the hash member of the oid member of struct object. This provides no
functional change, as it is essentially a macro substitution.
Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: Jeff King <peff@peff.net>
Convert most instances where the sha1 member of struct object is
dereferenced to use get_object_hash. Most instances that are passed to
functions that have versions taking struct object_id, such as
get_sha1_hex/get_oid_hex, or instances that can be trivially converted
to use struct object_id instead, are not converted.
Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: Jeff King <peff@peff.net>
When we call into xdiff to perform a diff, we generally lose
the return code completely. Typically by ignoring the return
of our xdi_diff wrapper, but sometimes we even propagate
that return value up and then ignore it later. This can
lead to us silently producing incorrect diffs (e.g., "git
log" might produce no output at all, not even a diff header,
for a content-level diff).
In practice this does not happen very often, because the
typical reason for xdiff to report failure is that it
malloc() failed (it uses straight malloc, and not our
xmalloc wrapper). But it could also happen when xdiff
triggers one our callbacks, which returns an error (e.g.,
outf() in builtin/rerere.c tries to report a write failure
in this way). And the next patch also plans to add more
failure modes.
Let's notice an error return from xdiff and react
appropriately. In most of the diff.c code, we can simply
die(), which matches the surrounding code (e.g., that is
what we do if we fail to load a file for diffing in the
first place). This is not that elegant, but we are probably
better off dying to let the user know there was a problem,
rather than simply generating bogus output.
We could also just die() directly in xdi_diff, but the
callers typically have a bit more context, and can provide a
better message (and if we do later decide to pass errors up,
we're one step closer to doing so).
There is one interesting case, which is in diff_grep(). Here
if we cannot generate the diff, there is nothing to match,
and we silently return "no hits". This is actually what the
existing code does already, but we make it a little more
explicit.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
"color.diff.plain" was a misnomer; give it 'color.diff.context' as
a more logical synonym.
* jk/color-diff-plain-is-context:
diff.h: rename DIFF_PLAIN color slot to DIFF_CONTEXT
diff: accept color.diff.context as a synonym for "plain"
The latter is a much more descriptive name (and we support
"color.diff.context" now). This also updates the name of any
local variables which were used to store the color.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Also, convert a constant to GIT_SHA1_HEXSZ.
Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
"git log --pretty/format=" with an empty format string did not mean
the more obvious "No output whatsoever" but "Use default format",
which was counterintuitive.
* jk/pretty-empty-format:
pretty: make empty userformats truly empty
pretty: treat "--format=" as an empty userformat
revision: drop useless string offset when parsing "--pretty"
When we do a combined diff, we individually diff against
each parent, and then use intersect_paths to do a parallel
walk through the sorted results and come up with a final
list of interesting paths.
The sort order here is that returned by the diffs, which
means it is in git's tree-order which sorts sub-trees as if
their paths have "/" at the end. When we do our parallel
walk, we need to use a comparison function which provides
the same order.
Since 8518ff8 (combine-diff: optimize combine_diff_path sets
intersection, 2014-01-20), we use a simple strcmp to
compare the pathnames, and get this wrong. It's somewhat
hard to trigger because normally a diff does not produce
tree entries at all, and therefore the sort order is the
same as a strcmp. However, if the "-t" option is used with
the diff, then we will produce diff_filepairs for both trees
and files.
We can use base_name_compare to do the comparison, just as
the tree-diff code does. Even though what we have are not
technically base names (they are full paths within the
tree), the end result is the same (we do not care about
interior slashes at all, only about the final character).
However, since we do not have the length of each path
stored, we take a slight shortcut: if neither of the entries
is a sub-tree then the comparison is equivalent to a strcmp.
This lets us skip the extra strlen calls in the common case
without having to reimplement base_name_compare from
scratch.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
If the user provides an empty format with "--format=", we
end up putting in extra whitespace that the user cannot
prevent. This comes from two places:
1. If the format is missing a terminating newline, we add
one automatically. This makes sense for --format=%h, but
not for a truly empty format.
2. We add an extra newline between the pretty-printed
format and a diff or diffstat. If the format is empty,
there's no point in doing so if there's nothing to
separate.
With this patch, one can get a diff with no other cruft out
of "diff-tree --format= $commit".
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
When git show -s is called for merge commit it prints extra newline
after any merge commit. This differs from output for commits with one
parent. Fix it by more thorough checking that diff output is disabled.
The code in question exists since commit 3969cf7db1. The additional
newline is really needed for cases when patch is requested, test
t4013-diff-various.sh contains cases which can demonstrate behavior when
the condition is restricted further.
Tests:
Added merge commit to 'set up a bit of history' case in t7007-show.sh to
cover the fix.
Existing tests are updated to demonstrate the new behaviour. Earlier,
the tests that used "git show -s --pretty=format:%s", even though
"--pretty=format:%s" calls for item separator semantics and does not ask
for the terminating newline after the last item, expected the output to
end with such a newline. They were relying on the buggy behaviour. Use
of "--format=%s", which is equivalent to "--pretty=tformat:%s" that asks
for a terminating newline after each item, is a more realistic way to
use the command.
In the test 'merge log messages' the expected data is changed, because
it was explicitly listing the extra newline. Also the msg.nologff and
msg.nolognoff expected files are replaced by one msg.nolog, because they
were diffing because of the bug, and now there should be no difference.
Signed-off-by: Max Kirillov <max@max630.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
As was recently shown in "combine-diff: optimize
combine_diff_path sets intersection", combine-diff runs very slowly. In
that commit we optimized paths sets intersection, but that accounted
only for ~ 25% of the slowness, and as my tracing showed, for linux.git
v3.10..v3.11, for merges a lot of time is spent computing
diff(commit,commit^2) just to only then intersect that huge diff to
almost small set of files from diff(commit,commit^1).
In previous commit, we described the problem in more details, and
reworked the diff tree-walker to be general one - i.e. to work in
multiple parent case too. Now is the time to take advantage of it for
finding paths for combine diff.
The implementation is straightforward - if we know, we can get generated
diff paths directly, and at present that means no diff filtering or
rename/copy detection was requested(*), we can call multiparent tree-walker
directly and get ready paths.
(*) because e.g. at present, all diffcore transformations work on
diff_filepair queues, but in the future, that limitation can be
lifted, if filters would operate directly on combine_diff_paths.
Timings for `git log --raw --no-abbrev --no-renames` without `-c` ("git log")
and with `-c` ("git log -c") and with `-c --merges` ("git log -c --merges")
before and after the patch are as follows:
linux.git v3.10..v3.11
log log -c log -c --merges
before 1.9s 16.4s 15.2s
after 1.9s 2.4s 1.1s
The result stayed the same.
Signed-off-by: Kirill Smelkov <kirr@mns.spb.ru>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Move code for finding paths for which diff(commit,parent_i) is not-empty
for all parents to separate function - at present we have generic (and
slow) code for this job, which translates 1 n-parent problem to n
1-parent problems and then intersect results, and will be adding another
limited, but faster, paths scanning implementation in the next patch.
Signed-off-by: Kirill Smelkov <kirr@mns.spb.ru>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Judging from sample outputs and tests nothing changes in diff -c output,
and this change will help later patches, when we'll be refactoring paths
scanning into its own function with several variants - the
show_log_first logic / code will stay common to all of them.
NOTE: only now we have to take care to explicitly not show anything if
parents array is empty, as in fact there are some clients in Git code,
which calls diff_tree_combined() in such a way.
Signed-off-by: Kirill Smelkov <kirr@mns.spb.ru>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Linus once said:
I actually wish more people understood the really core low-level
kind of coding. Not big, complex stuff like the lockless name
lookup, but simply good use of pointers-to-pointers etc. For
example, I've seen too many people who delete a singly-linked
list entry by keeping track of the "prev" entry, and then to
delete the entry, doing something like
if (prev)
prev->next = entry->next;
else
list_head = entry->next;
and whenever I see code like that, I just go "This person
doesn't understand pointers". And it's sadly quite common.
People who understand pointers just use a "pointer to the entry
pointer", and initialize that with the address of the
list_head. And then as they traverse the list, they can remove
the entry without using any conditionals, by just doing a "*pp =
entry->next".
Applying that simplification lets us lose 7 lines from this function
even while adding 2 lines of comment.
I was tempted to squash this into the original commit, but because
the benchmarking described in the commit log is without this
simplification, I decided to keep it a separate follow-up patch.
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The field was used in order to speed-up name comparison and also to
mark removed paths by setting it to 0.
Because the updated code does significantly less strcmp and also
just removes paths from the list and free right after we know a path
will not be needed, it is not needed anymore.
Signed-off-by: Kirill Smelkov <kirr@mns.spb.ru>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
When generating combined diff, for each commit, we intersect diff
paths from diff(parent_0,commit) to diff(parent_i,commit) comparing
all paths pairs, i.e. doing it the quadratic way. That is correct,
but could be optimized.
Paths come from trees in sorted (= tree) order, and so does diff_tree()
emits resulting paths in that order too. Now if we look at diffcore
transformations, all of them, except diffcore_order, preserve resulting
path ordering:
- skip_stat_unmatch, grep, pickaxe, filter
-- just skip elements -> order stays preserved
- break -- just breaks diff for a path, adding path
dup after the path -> order stays preserved
- detect rename/copy -- resulting paths are emitted sorted
(verified empirically)
So only diffcore_order changes diff paths ordering.
But diffcore_order meaning affects only presentation - i.e. only how to
show the diff, so we could do all the internal computations without
paths reordering, and order only resultant paths set. This is faster,
since, if we know two paths sets are all ordered, their intersection
could be done in linear time.
This patch does just that.
Timings for `git log --raw --no-abbrev --no-renames` without `-c` ("git log")
and with `-c` ("git log -c") before and after the patch are as follows:
linux.git v3.10..v3.11
log log -c
before 1.9s 20.4s
after 1.9s 16.6s
navy.git (private repo)
log log -c
before 0.83s 15.6s
after 0.83s 2.1s
P.S.
I think linux.git case is sped up not so much as the second one, since
in navy.git, there are more exotic (subtree, etc) merges.
P.P.S.
My tracing showed that the rest of the time (16.6s vs 1.9s) is usually
spent in computing huge diffs from commit to second parent. Will try to
deal with it, if I'll have time.
P.P.P.S.
For combine_diff_path, ->len is not needed anymore - will remove it in
the next noisy cleanup path, to maintain good signal/noise ratio here.
Signed-off-by: Kirill Smelkov <kirr@mns.spb.ru>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
"git mv A B" when moving a submodule A does "the right thing",
inclusing relocating its working tree and adjusting the paths in
the .gitmodules file.
* jl/submodule-mv: (53 commits)
rm: delete .gitmodules entry of submodules removed from the work tree
mv: update the path entry in .gitmodules for moved submodules
submodule.c: add .gitmodules staging helper functions
mv: move submodules using a gitfile
mv: move submodules together with their work trees
rm: do not set a variable twice without intermediate reading.
t6131 - skip tests if on case-insensitive file system
parse_pathspec: accept :(icase)path syntax
pathspec: support :(glob) syntax
pathspec: make --literal-pathspecs disable pathspec magic
pathspec: support :(literal) syntax for noglob pathspec
kill limit_pathspec_to_literal() as it's only used by parse_pathspec()
parse_pathspec: preserve prefix length via PATHSPEC_PREFIX_ORIGIN
parse_pathspec: make sure the prefix part is wildcard-free
rename field "raw" to "_raw" in struct pathspec
tree-diff: remove the use of pathspec's raw[] in follow-rename codepath
remove match_pathspec() in favor of match_pathspec_depth()
remove init_pathspec() in favor of parse_pathspec()
remove diff_tree_{setup,release}_paths
convert common_prefix() to use struct pathspec
...
Output from "git log --full-diff -- <pathspec>" looked strange,
because comparison was done with the previous ancestor that touched
the specified <pathspec>, causing the patches for paths outside the
pathspec to show more than the single commit has changed.
Tweak "git reflog -p" for the same reason using the same mechanism.
* tr/log-full-diff-keep-true-parents:
log: use true parents for diff when walking reflogs
log: use true parents for diff even when rewriting
When using pathspec filtering in combination with diff-based log
output, parent simplification happens before the diff is computed.
The diff is therefore against the *simplified* parents.
This works okay, arguably by accident, in the normal case:
simplification reduces to one parent as long as the commit is TREESAME
to it. So the simplified parent of any given commit must have the
same tree contents on the filtered paths as its true (unfiltered)
parent.
However, --full-diff breaks this guarantee, and indeed gives pretty
spectacular results when comparing the output of
git log --graph --stat ...
git log --graph --full-diff --stat ...
(--graph internally kicks in parent simplification, much like
--parents).
To fix it, store a copy of the parent list before simplification (in a
slab) whenever --full-diff is in effect. Then use the stored parents
instead of the simplified ones in the commit display code paths. The
latter do not actually check for --full-diff to avoid duplicated code;
they just grab the original parents if save_parents() has not been
called for this revision walk.
For ordinary commits it should be obvious that this is the right thing
to do.
Merge commits are a bit subtle. Observe that with default
simplification, merge simplification is an all-or-nothing decision:
either the merge is TREESAME to one parent and disappears, or it is
different from all parents and the parent list remains intact.
Redundant parents are not pruned, so the existing code also shows them
as a merge.
So if we do show a merge commit, the parent list just consists of the
rewrite result on each parent. Running, e.g., --cc on this in
--full-diff mode is not very useful: if any commits were skipped, some
hunks will disagree with all sides of the merge (with one side,
because commits were skipped; with the others, because they didn't
have those changes in the first place). This triggers --cc showing
these hunks spuriously.
Therefore I believe that even for merge commits it is better to show
the diffs wrt. the original parents.
Reported-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Helped-by: Junio C Hamano <gitster@pobox.com>
Helped-by: Ramsay Jones <ramsay@ramsay1.demon.co.uk>
Signed-off-by: Thomas Rast <trast@inf.ethz.ch>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
"git diff -c -p" was not showing a deleted line from a hunk when
another hunk immediately begins where the earlier one ends.
* mk/combine-diff-context-horizon-fix:
combine-diff.c: Fix output when changes are exactly 3 lines apart
In diff_tree_combined we make a copy of diffopts. In
try_to_follow_renames, called via diff_tree_sha1, we free and
re-initialize diffopts->pathspec->items. Since we did not make a deep
copy of diffopts in diff_tree_combined, the original diffopts does not
get the update. By the time we return from diff_tree_combined,
rev->diffopt->pathspec->items points to an invalid memory address. We
get a segfault next time we try to access that pathspec.
Instead, along with the copy of diffopts, make a copy pathspec->items as
well.
We would also have to make a copy of pathspec->raw to keep it consistent
with pathspec->items, but nobody seems to rely on that.
Signed-off-by: Clemens Buchacher <drizzd@aon.at>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
When a deletion is followed by exactly 3 (or whatever the number of
context lines) unchanged lines, followed by another change, the combined
diff output would hide the first deletion, resulting in a malformed
diff.
This happened because the 3 lines before each change are painted
interesting, but also marked as no_pre_delete to prevent showing deletes
that were previously marked as uninteresting. This behaviour was
introduced in c86fbe53 (diff -c/--cc: do not include uninteresting
deletion before leading context). However, as a side effect, this could
also mark deletes that were already interesting as no_pre_delete. This
would happen only if the delete was exactly 3 lines away from the next
change, since lines farther away would not be touched by the "paint
three lines before the change" code and lines closer would be painted
by the "merge two adjacent hunks" code instead, which does not set the
no_pre_delete flag.
This commit fixes this problem by only setting the no_pre_delete flag
for changes that were previously uninteresting.
Signed-off-by: Matthijs Kooijman <matthijs@stdin.nl>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This replaces the greedy implementation to coalesce lost lines by using
dynamic programming to find the Longest Common Subsequence.
The O(n²) time complexity is obviously bigger than previous
implementation but it can produce shorter diff results (and most likely
easier to read).
List of lost lines is now doubly-linked because we reverse-read it when
reading the direction matrix.
Signed-off-by: Antoine Pelisse <apelisse@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The combined diff --cc output does not honor options to ignore
whitespace changes (-b, -w, and --ignore-space-at-eol).
Correct this by passing diff flags to diff engine, so that combined
diff behaves as normal diff does with spaces, and by coalescing
lines that are removed from both (or more) parents, honoring the
same rule to ignore whitespace changes.
With this change, a conflict-less merge done using a ignore-*
strategy option will not show any conflict if shown in combined-diff
using the same option.
Signed-off-by: Antoine Pelisse <apelisse@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Refactors a lot of repetitive code sequence from the graph drawing
code and adds it to the combined diff output.
* jk/diff-graph-cleanup:
combine-diff.c: teach combined diffs about line prefix
diff.c: use diff_line_prefix() where applicable
diff: add diff_line_prefix function
diff.c: make constant string arguments const
diff: write prefix to the correct file
graph: output padding for merge subsequent parents
When running "git log --graph --cc -p" the diff output for merges is not
indented by the graph structure, unlike the diffs of non-merge commits
(added in commit 7be5761 - diff.c: Output the text graph padding before
each diff line).
Fix this by teaching the combined diff code to output diff_line_prefix()
before each line.
Signed-off-by: John Keeping <john@keeping.me.uk>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The "raw" format of combine-diff output is supposed to have as many
colons as there are parents at the beginning, then blob modes for
these parents, and then object names for these parents.
We weren't however prepared to handle a more than 32-way merge and
did not show the correct number of colons in such a case.
Signed-off-by: Junio C Hamano <gitster@pobox.com>
"git diff" had a confusion between taking data from a path in the
working tree and taking data from an object that happens to have
name 0{40} recorded in a tree.
* jk/maint-null-in-trees:
fsck: detect null sha1 in tree entries
do not write null sha1s to on-disk index
diff: do not use null sha1 as a sentinel value
We do not want a link to 0{40} object stored anywhere in our objects.
* jk/maint-null-in-trees:
fsck: detect null sha1 in tree entries
do not write null sha1s to on-disk index
diff: do not use null sha1 as a sentinel value
The diff code represents paths using the diff_filespec
struct. This struct has a sha1 to represent the sha1 of the
content at that path, as well as a sha1_valid member which
indicates whether its sha1 field is actually useful. If
sha1_valid is not true, then the filespec represents a
working tree file (e.g., for the no-index case, or for when
the index is not up-to-date).
The diff_filespec is only used internally, though. At the
interfaces to the diff subsystem, callers feed the sha1
directly, and we create a diff_filespec from it. It's at
that point that we look at the sha1 and decide whether it is
valid or not; callers may pass the null sha1 as a sentinel
value to indicate that it is not.
We should not typically see the null sha1 coming from any
other source (e.g., in the index itself, or from a tree).
However, a corrupt tree might have a null sha1, which would
cause "diff --patch" to accidentally diff the working tree
version of a file instead of treating it as a blob.
This patch extends the edges of the diff interface to accept
a "sha1_valid" flag whenever we accept a sha1, and to use
that flag when creating a filespec. In some cases, this
means passing the flag through several layers, making the
code change larger than would be desirable.
One alternative would be to simply die() upon seeing
corrupted trees with null sha1s. However, this fix more
directly addresses the problem (while bogus sha1s in a tree
are probably a bad thing, it is really the sentinel
confusion sending us down the wrong code path that is what
makes it devastating). And it means that git is more capable
of examining and debugging these corrupted trees. For
example, you can still "diff --raw" such a tree to find out
when the bogus entry was introduced; you just cannot do a
"--patch" diff (just as you could not with any other
corrupted tree, as we do not have any content to diff).
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Fixes an age old corner case bug in combine diff (only triggered with -U0
and the hunk at the beginning of the file needs to be shown).
By René Scharfe
* rs/combine-diff-zero-context-at-the-beginning:
combine-diff: fix loop index underflow
If both la and context are zero at the start of the loop, la wraps around
and we end up reading from memory far away. Skip the loop in that case
instead.
Reported-by: Julia Lawall <julia.lawall@lip6.fr>
Signed-off-by: Rene Scharfe <rene.scharfe@lsrfire.ath.cx>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Instead of passing the hash of a commit and then searching that
same commit in the single caller, simply pass the commit directly.
Signed-off-by: René Scharfe <rene.scharfe@lsrfire.ath.cx>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Maintaining an array of hashes is easier using sha1_array than
open-coding it. This patch also fixes a leak of the SHA1 array
in diff_tree_combined_merge().
Signed-off-by: René Scharfe <rene.scharfe@lsrfire.ath.cx>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
* jk/color-and-pager:
want_color: automatically fallback to color.ui
diff: don't load color config in plumbing
config: refactor get_colorbool function
color: delay auto-color decision until point of use
git_config_colorbool: refactor stdout_is_tty handling
diff: refactor COLOR_DIFF from a flag into an int
setup_pager: set GIT_PAGER_IN_USE
t7006: use test_config helpers
test-lib: add helper functions for config
t7006: modernize calls to unset
Conflicts:
builtin/commit.c
parse-options.c
This teaches combine-diff machinery to feed a combined merge to a callback
function when DIFF_FORMAT_CALLBACK is specified.
So far, format callback functions are not used for anything but 2-way
diffs. A callback is given a diff_queue_struct, which is an array of
diff_filepair. As its name suggests, a diff_filepair is a _pair_ of
diff_filespec that represents a single preimage and a single postimage.
Since "diff -c" is to compare N parents with a single merge result and
filter out any paths whose result match one (or more) of the parent(s),
its output has to be able to represent N preimages and 1 postimage. For
this reason, a callback function that inspects a diff_filepair that
results from this new infrastructure can and is expected to view the
preimage side (i.e. pair->one) as an array of diff_filespec. Each element
in the array, except for the last one, is marked with "has_more_entries"
bit, so that the same callback function can be used for 2-way diffs and
combined diffs.
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This lets us store more than just a bit flag for whether we
want color; we can also store whether we want automatic
colors. This can be useful for making the automatic-color
decision closer to the point of use.
This mostly just involves replacing DIFF_OPT_* calls with
manipulations of the flag. The biggest exception is that
calls to DIFF_OPT_TST must check for "o->use_color > 0",
which lets an "unknown" value (i.e., the default) stay at
"no color". In the previous code, a value of "-1" was not
propagated at all.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
