Commit graph

382 commits

Author SHA1 Message Date
Junio C Hamano 26c816a67d Merge branch 'hw/doc-in-header'
* hw/doc-in-header:
  trace2: move doc to trace2.h
  submodule-config: move doc to submodule-config.h
  tree-walk: move doc to tree-walk.h
  trace: move doc to trace.h
  run-command: move doc to run-command.h
  parse-options: add link to doc file in parse-options.h
  credential: move doc to credential.h
  argv-array: move doc to argv-array.h
  cache: move doc to cache.h
  sigchain: move doc to sigchain.h
  pathspec: move doc to pathspec.h
  revision: move doc to revision.h
  attr: move doc to attr.h
  refs: move doc to refs.h
  remote: move doc to remote.h and refspec.h
  sha1-array: move doc to sha1-array.h
  merge: move doc to ll-merge.h
  graph: move doc to graph.h and graph.c
  dir: move doc to dir.h
  diff: move doc to diff.h and diffcore.h
2019-12-16 13:08:39 -08:00
Heba Waly 13c4d7eb22 diff: move doc to diff.h and diffcore.h
Move the documentation from Documentation/technical/api-diff.txt to both
diff.h and diffcore.h as it's easier for the developers to find the usage
information beside the code instead of looking for it in another doc file.

Also documentation/technical/api-diff.txt is removed because the information
it has is now redundant and it'll be hard to keep it up to date and
synchronized with the documentation in the header files.

There are three members documented in the doc file that weren't found in
the header files, assuming the doc wasn't up to date and the members
no longer exist:
touched_flags, COLOR_DIFF_WORDS and QUIET.

Signed-off-by: Heba Waly <heba.waly@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-11-18 15:21:28 +09:00
Daniel Ferreira e4cb659ebd diff: export diffstat interface
Make the diffstat interface (namely, the diffstat_t struct and
compute_diffstat) no longer be internal to diff.c and allow it to be used
by other parts of git.

This is helpful for code that may want to easily extract information
from files using the diff machinery, while flushing it differently from
how the show_* functions used by diff_flush() do it. One example is the
builtin implementation of git-add--interactive's status.

Signed-off-by: Daniel Ferreira <bnmvco@gmail.com>
Signed-off-by: Slavica Đukić <slawica92@hotmail.com>
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-11-14 11:10:04 +09:00
brian m. carlson 36261e42ec patch-id: convert to use the_hash_algo
Convert the two separate patch-id implementations to use the_hash_algo
in their implementation.

Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-08-19 15:04:57 -07:00
Thomas Gummerer 430be36eb5 range-diff: suppress line count in outer diff
The line count in the outer diff's hunk headers of a range diff is not
all that interesting.  It merely shows how far along the inner diff
are on both sides.  That number is of no use for human readers, and
range-diffs are not meant to be machine readable.

In a subsequent commit we're going to add some more contextual
information such as the filename corresponding to the diff to the hunk
headers.  Remove the unnecessary information, and just keep the "@@"
to indicate that a new hunk of the outer diff is starting.

Signed-off-by: Thomas Gummerer <t.gummerer@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-07-11 14:29:27 -07:00
Junio C Hamano 8202d12fca Merge branch 'sb/format-patch-base-patch-id-fix'
The "--base" option of "format-patch" computed the patch-ids for
prerequisite patches in an unstable way, which has been updated to
compute in a way that is compatible with "git patch-id --stable".

* sb/format-patch-base-patch-id-fix:
  format-patch: make --base patch-id output stable
  format-patch: inform user that patch-id generation is unstable
2019-06-13 13:18:46 -07:00
Junio C Hamano 20aa7c594f Merge branch 'nd/diff-parseopt'
A brown-paper-bag bugfix to a change already in 'master'.

* nd/diff-parseopt:
  parse-options: check empty value in OPT_INTEGER and OPT_ABBREV
  diff-parseopt: restore -U (no argument) behavior
  diff-parseopt: correct variable types that are used by parseopt
2019-05-30 10:50:44 -07:00
Nguyễn Thái Ngọc Duy 7f125ff909 diff-parseopt: correct variable types that are used by parseopt
Most number-related OPT_ macros store the value in an 'int'
variable. Many of the variables in 'struct diff_options' have a
different type, but during the conversion to using parse_options() I
failed to notice and correct.

The problem was reported on s360x which is a big-endian
architechture. The variable to store '-w' option in this case is
xdl_opts, 'long' type, 8 bytes. But since parse_options() assumes
'int' (4 bytes), it will store bits in the wrong part of xdl_opts. The
problem was found on little-endian platforms because parse_options()
will accidentally store at the right part of xdl_opts.

There aren't much to say about the type change (except that 'int' for
xdl_opts should still be big enough, since Windows' long is the same
size as 'int' and nobody has complained so far). Some safety checks may
be implemented in the future to prevent class of bugs.

Reported-by: Todd Zullinger <tmz@pobox.com>
Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-05-29 11:04:30 -07:00
Stephen Boyd a8f6855f48 format-patch: make --base patch-id output stable
We weren't flushing the context each time we processed a hunk in the
patch-id generation code in diff.c, but we were doing that when we
generated "stable" patch-ids with the 'patch-id' tool. Let's port that
similar logic over from patch-id.c into diff.c so we can get the same
hash when we're generating patch-ids for 'format-patch --base=' types of
command invocations.

Cc: Xiaolong Ye <xiaolong.ye@intel.com>
Signed-off-by: Stephen Boyd <sboyd@kernel.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-05-08 19:27:43 +09:00
Junio C Hamano dcd6a8c09a Merge branch 'nd/diff-parseopt-4'
Fourth batch to teach the diff machinery to use the parse-options
API.

* nd/diff-parseopt-4:
  am: avoid diff_opt_parse()
  diff --no-index: use parse_options() instead of diff_opt_parse()
  range-diff: use parse_options() instead of diff_opt_parse()
  diff.c: allow --no-color-moved-ws
  diff-parseopt: convert --color-moved-ws
  diff-parseopt: convert --[no-]color-moved
  diff-parseopt: convert --inter-hunk-context
  diff-parseopt: convert --no-prefix
  diff-parseopt: convert --line-prefix
  diff-parseopt: convert --[src|dst]-prefix
  diff-parseopt: convert --[no-]abbrev
  diff-parseopt: convert --diff-filter
  diff-parseopt: convert --find-object
  diff-parseopt: convert -O
  diff-parseopt: convert --pickaxe-all|--pickaxe-regex
  diff-parseopt: convert -S|-G
  diff-parseopt: convert -l
  diff-parseopt: convert -z
  diff-parseopt: convert --ita-[in]visible-in-index
  diff-parseopt: convert --ws-error-highlight
2019-04-25 16:41:12 +09:00
Nguyễn Thái Ngọc Duy cdb5330a9b am: avoid diff_opt_parse()
diff_opt_parse() is a heavy hammer to just set diff filter. But it's
the only way because of the diff_status_letters[] mapping. Add a new
API to set diff filter and use it in git-am. diff_opt_parse()'s only
remaining call site in revision.c will be gone soon and having it here
just because of git-am does not make sense.

Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-03-24 22:21:24 +09:00
Nguyễn Thái Ngọc Duy 16bb3d714d diff --no-index: use parse_options() instead of diff_opt_parse()
While at there, move exit() back to the caller. It's easier to see the
flow that way than burying it in diff-no-index.c

Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-03-24 22:21:24 +09:00
Junio C Hamano 12e5bdd9c4 Merge branch 'jk/diff-no-index-initialize'
"git diff --no-index" may still want to access Git goodies like
--ext-diff and --textconv, but so far these have been ignored,
which has been corrected.

* jk/diff-no-index-initialize:
  diff: reuse diff setup for --no-index case
2019-03-07 09:59:59 +09:00
Junio C Hamano 1dc2f8c122 Merge branch 'jk/unused-params'
Code clean-up.

* jk/unused-params:
  ref-filter: drop unused "sz" parameters
  ref-filter: drop unused "obj" parameters
  ref-filter: drop unused buf/sz pairs
  files-backend: drop refs parameter from split_symref_update()
  pack-objects: drop unused parameter from oe_map_new_pack()
  merge-recursive: drop several unused parameters
  diff: drop complete_rewrite parameter from run_external_diff()
  diff: drop unused emit data parameter from sane_truncate_line()
  diff: drop unused color reset parameters
  diff: drop options parameter from diffcore_fix_diff_index()
2019-03-07 09:59:57 +09:00
Junio C Hamano c425d361f5 Merge branch 'en/combined-all-paths'
Output from "diff --cc" did not show the original paths when the
merge involved renames.  A new option adds the paths in the
original trees to the output.

* en/combined-all-paths:
  log,diff-tree: add --combined-all-paths option
2019-03-07 09:59:54 +09:00
Jeff King 287ab28bfa diff: reuse diff setup for --no-index case
When "--no-index" is in effect (or implied by the arguments), git-diff
jumps early to a special code path to perform that diff. This means we
miss out on some settings like enabling --ext-diff and --textconv by
default.

Let's jump to the no-index path _after_ we've done more setup on
rev.diffopt. Since some of the options don't affect us (e.g., items
related to the index), let's re-order the setup into two blocks (see the
in-code comments).

Note that we also need to stop re-initializing the diffopt struct in
diff_no_index(). This should not be necessary, as it will already have
been initialized by cmd_diff() (and there are no other callers). That in
turn lets us drop the "repository" argument from diff_no_index (which
never made much sense, since the whole point is that you don't need a
repository).

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-02-24 07:08:34 -08:00
Jeff King 784c0daed5 diff: drop options parameter from diffcore_fix_diff_index()
The sole purpose of this function is to fix the sorting order of the
queued diff entries. It doesn't need to know about any diff options, so
we can drop the unused parameter.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-02-14 15:26:14 -08:00
Elijah Newren d76ce4f734 log,diff-tree: add --combined-all-paths option
The combined diff format for merges will only list one filename, even if
rename or copy detection is active.  For example, with raw format one
might see:

  ::100644 100644 100644 fabadb8 cc95eb0 4866510 MM	describe.c
  ::100755 100755 100755 52b7a2d 6d1ac04 d2ac7d7 RM	bar.sh
  ::100644 100644 100644 e07d6c5 9042e82 ee91881 RR	phooey.c

This doesn't let us know what the original name of bar.sh was in the
first parent, and doesn't let us know what either of the original names
of phooey.c were in either of the parents.  In contrast, for non-merge
commits, raw format does provide original filenames (and a rename score
to boot).  In order to also provide original filenames for merge
commits, add a --combined-all-paths option (which must be used with
either -c or --cc, and is likely only useful with rename or copy
detection active) so that we can print tab-separated filenames when
renames are involved.  This transforms the above output to:

  ::100644 100644 100644 fabadb8 cc95eb0 4866510 MM	desc.c	desc.c	desc.c
  ::100755 100755 100755 52b7a2d 6d1ac04 d2ac7d7 RM	foo.sh	bar.sh	bar.sh
  ::100644 100644 100644 e07d6c5 9042e82 ee91881 RR	fooey.c	fuey.c	phooey.c

Further, in patch format, this changes the from/to headers so that
instead of just having one "from" header, we get one for each parent.
For example, instead of having

  --- a/phooey.c
  +++ b/phooey.c

we would see

  --- a/fooey.c
  --- a/fuey.c
  +++ b/phooey.c

Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-02-07 20:15:25 -08:00
Nguyễn Thái Ngọc Duy 4a28847839 diff.c: prepare to use parse_options() for parsing
This is a preparation step to start using parse_options() to parse
diff/revision options instead of what we have now. There are a couple
of good things from using parse_options():

- better help usage
- easier to add new options
- better completion support
- help usage generation
- better integration with main command option parser. We can just
  concat the main command's option array and diffopt's together and
  parse all in one go.
- detect colidding options (e.g. --reverse is used by revision code,
  so diff code can't use it as long name for -R)
- consistent syntax, e.g. option that takes mandatory argument will
  now accept both "--option=value" and "--option value".

The plan is migrate all diff/rev options to parse_options(). Then we
could get rid of diff_opt_parse() and expose parseopts[] directly to
the caller.

Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-01-27 16:28:18 -08:00
Nguyễn Thái Ngọc Duy 2b393ef357 diff.h: avoid bit fields in struct diff_flags
Bitfield addresses cannot be passed around in a pointer. This makes it
hard to use parse-options to set/unset them. Turn this struct to
normal integers. This of course increases the size of this struct
multiple times, but since we only have a handful of diff_options
variables around, memory consumption is not at all a concern.

Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-01-27 16:28:18 -08:00
Nguyễn Thái Ngọc Duy 4a1b13a397 diff.h: keep forward struct declarations sorted
Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-01-27 16:28:18 -08:00
Junio C Hamano 932b867be0 Merge branch 'sb/diff-color-moved-config-option-fixup'
Minor inconsistency fix.

* sb/diff-color-moved-config-option-fixup:
  diff: align move detection error handling with other options
2019-01-14 15:29:31 -08:00
Stefan Beller d173e799ea diff: align move detection error handling with other options
This changes the error handling for the options --color-moved-ws
and --color-moved-ws to be like the rest of the options.

Move the die() call out of parse_color_moved_ws into the parsing
of command line options. As the function returns a bit field, change
its signature to return an unsigned instead of an int; add a new bit
to signal errors. Once the error is signaled, we discard the other
bits, such that it doesn't matter if the error bit overlaps with any
other bit.

Signed-off-by: Stefan Beller <sbeller@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-11-14 16:27:50 +09:00
Nguyễn Thái Ngọc Duy bd7ad45b64 notes-cache.c: remove the_repository references
Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-11-12 14:50:06 +09:00
Nguyễn Thái Ngọc Duy ffc00a48ef diff-lib.c: remove the_repository references
Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-11-12 14:50:06 +09:00
Junio C Hamano 11877b9ebe Merge branch 'nd/the-index'
Various codepaths in the core-ish part learn to work on an
arbitrary in-core index structure, not necessarily the default
instance "the_index".

* nd/the-index: (23 commits)
  revision.c: reduce implicit dependency the_repository
  revision.c: remove implicit dependency on the_index
  ws.c: remove implicit dependency on the_index
  tree-diff.c: remove implicit dependency on the_index
  submodule.c: remove implicit dependency on the_index
  line-range.c: remove implicit dependency on the_index
  userdiff.c: remove implicit dependency on the_index
  rerere.c: remove implicit dependency on the_index
  sha1-file.c: remove implicit dependency on the_index
  patch-ids.c: remove implicit dependency on the_index
  merge.c: remove implicit dependency on the_index
  merge-blobs.c: remove implicit dependency on the_index
  ll-merge.c: remove implicit dependency on the_index
  diff-lib.c: remove implicit dependency on the_index
  read-cache.c: remove implicit dependency on the_index
  diff.c: remove implicit dependency on the_index
  grep.c: remove implicit dependency on the_index
  diff.c: remove the_index dependency in textconv() functions
  blame.c: rename "repo" argument to "r"
  combine-diff.c: remove implicit dependency on the_index
  ...
2018-10-19 13:34:02 +09:00
Nguyễn Thái Ngọc Duy acd00ea049 userdiff.c: remove implicit dependency on the_index
[jc: squashed in missing forward decl in userdiff.h found by Ramsay]

Helped-by: Ramsay Jones <ramsay@ramsayjones.plus.com>
Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-09-21 09:50:58 -07:00
Nguyễn Thái Ngọc Duy e675765235 diff.c: remove implicit dependency on the_index
A new variant repo_diff_setup() is added that takes 'struct repository *'
and diff_setup() becomes a thin macro around it that is protected by
NO_THE_REPOSITORY_COMPATIBILITY_MACROS, similar to NO_THE_INDEX_....
The plan is these macros will always be defined for all library files
and the macros are only accessible in builtin/

Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-09-21 09:48:10 -07:00
Nguyễn Thái Ngọc Duy 6afaf80785 diff.c: remove the_index dependency in textconv() functions
Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-09-21 09:48:10 -07:00
Nguyễn Thái Ngọc Duy b78ea5fc35 diff.c: reduce implicit dependency on the_index
diff and textconv code has so widespread use that it's hard to simply
update their api and all call sites at once because it would result in
a big patch. For now reduce the_index references to two places:
diff_setup() and fill_textconv().

Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-09-21 09:48:10 -07:00
Junio C Hamano 30035d1d60 Merge branch 'sb/range-diff-colors'
The color output support for recently introduced "range-diff"
command got tweaked a bit.

* sb/range-diff-colors:
  range-diff: indent special lines as context
  range-diff: make use of different output indicators
  diff.c: add --output-indicator-{new, old, context}
  diff.c: rewrite emit_line_0 more understandably
  diff.c: omit check for line prefix in emit_line_0
  diff: use emit_line_0 once per line
  diff.c: add set_sign to emit_line_0
  diff.c: reorder arguments for emit_line_ws_markup
  diff.c: simplify caller of emit_line_0
  t3206: add color test for range-diff --dual-color
  test_decode_color: understand FAINT and ITALIC
2018-09-17 13:53:54 -07:00
Stefan Beller 7648b79eee diff.c: add --output-indicator-{new, old, context}
This will prove useful in range-diff in a later patch as we will be able to
differentiate between adding a new file (that line is starting with +++
and then the file name) and regular new lines.

It could also be useful for experimentation in new patch formats, i.e.
we could teach git to emit moved lines with lines other than +/-.

Signed-off-by: Stefan Beller <sbeller@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-08-20 14:33:24 -07:00
Junio C Hamano 81eab6871e Merge branch 'js/range-diff'
"git tbdiff" that lets us compare individual patches in two
iterations of a topic has been rewritten and made into a built-in
command.

* js/range-diff: (21 commits)
  range-diff: use dim/bold cues to improve dual color mode
  range-diff: make --dual-color the default mode
  range-diff: left-pad patch numbers
  completion: support `git range-diff`
  range-diff: populate the man page
  range-diff --dual-color: skip white-space warnings
  range-diff: offer to dual-color the diffs
  diff: add an internal option to dual-color diffs of diffs
  color: add the meta color GIT_COLOR_REVERSE
  range-diff: use color for the commit pairs
  range-diff: add tests
  range-diff: do not show "function names" in hunk headers
  range-diff: adjust the output of the commit pairs
  range-diff: suppress the diff headers
  range-diff: indent the diffs just like tbdiff
  range-diff: right-trim commit messages
  range-diff: also show the diff between patches
  range-diff: improve the order of the shown commits
  range-diff: first rudimentary implementation
  Introduce `range-diff` to compare iterations of a topic branch
  ...
2018-08-20 11:33:53 -07:00
Nguyễn Thái Ngọc Duy ff7fe37b05 diff.c: move read_index() code back to the caller
This code is only needed for diff-tree (since f0c6b2a2fd ([PATCH]
Optimize diff-tree -[CM] --stdin - 2005-05-27)). Let the caller do the
preparation instead and avoid read_index() in diff.c code.

read_index() should be avoided (in addition to the_index) because it
uses get_index_file() underneath to get the path $GIT_DIR/index. This
effectively pulls the_repository in and may become the only reason to
pull a 'struct repository *' in diff.c. Let's keep the dependencies as
few as possible and kick it back to diff-tree.c

Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-08-13 14:14:42 -07:00
Johannes Schindelin a7be92acd9 range-diff: use dim/bold cues to improve dual color mode
It *is* a confusing thing to look at a diff of diffs. All too easy is it
to mix up whether the -/+ markers refer to the "inner" or the "outer"
diff, i.e. whether a `+` indicates that a line was added by either the
old or the new diff (or both), or whether the new diff does something
different than the old diff.

To make things easier to process for normal developers, we introduced
the dual color mode which colors the lines according to the commit diff,
i.e. lines that are added by a commit (whether old, new, or both) are
colored in green. In non-dual color mode, the lines would be colored
according to the outer diff: if the old commit added a line, it would be
colored red (because that line addition is only present in the first
commit range that was specified on the command-line, i.e. the "old"
commit, but not in the second commit range, i.e. the "new" commit).

However, this dual color mode is still not making things clear enough,
as we are looking at two levels of diffs, and we still only pick a color
according to *one* of them (the outer diff marker is colored
differently, of course, but in particular with deep indentation, it is
easy to lose track of that outer diff marker's background color).

Therefore, let's add another dimension to the mix. Still use
green/red/normal according to the commit diffs, but now also dim the
lines that were only in the old commit, and use bold face for the lines
that are only in the new commit.

That way, it is much easier not to lose track of, say, when we are
looking at a line that was added in the previous iteration of a patch
series but the new iteration adds a slightly different version: the
obsolete change will be dimmed, the current version of the patch will be
bold.

At least this developer has a much easier time reading the range-diffs
that way.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-08-13 10:44:52 -07:00
Johannes Schindelin f7c3b4e2d8 diff: add an internal option to dual-color diffs of diffs
When diffing diffs, it can be quite daunting to figure out what the heck
is going on, as there are nested +/- signs.

Let's make this easier by adding a flag in diff_options that allows
color-coding the outer diff sign with inverted colors, so that the
preimage and postimage is colored like the diff it is.

Of course, this really only makes sense when the preimage and postimage
*are* diffs. So let's not expose this flag via a command-line option for
now.

This is a feature that was invented by git-tbdiff, and it will be used
by `git range-diff` in the next commit, by offering it via a new option:
`--dual-color`.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-08-13 10:44:51 -07:00
Johannes Schindelin 1cdde296a5 range-diff: suppress the diff headers
When showing the diff between corresponding patches of the two branch
versions, we have to make up a fake filename to run the diff machinery.

That filename does not carry any meaningful information, hence tbdiff
suppresses it. So we should, too.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-08-13 10:44:51 -07:00
Nguyễn Thái Ngọc Duy f758a7f8ac diff.h: remove extern from function declaration
Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-08-03 10:42:55 -07:00
Junio C Hamano a81575aa91 Merge branch 'sb/diff-color-move-more'
"git diff --color-moved" feature has further been tweaked.

* sb/diff-color-move-more:
  diff.c: offer config option to control ws handling in move detection
  diff.c: add white space mode to move detection that allows indent changes
  diff.c: factor advance_or_nullify out of mark_color_as_moved
  diff.c: decouple white space treatment from move detection algorithm
  diff.c: add a blocks mode for moved code detection
  diff.c: adjust hash function signature to match hashmap expectation
  diff.c: do not pass diff options as keydata to hashmap
  t4015: avoid git as a pipe input
  xdiff/xdiffi.c: remove unneeded function declarations
  xdiff/xdiff.h: remove unused flags
2018-08-02 15:30:40 -07:00
Stefan Beller ca1f4ae4df diff.c: add white space mode to move detection that allows indent changes
The option of --color-moved has proven to be useful as observed on the
mailing list. However when refactoring sometimes the indentation changes,
for example when partitioning a functions into smaller helper functions
the code usually mostly moved around except for a decrease in indentation.

To just review the moved code ignoring the change in indentation, a mode
to ignore spaces in the move detection as implemented in a previous patch
would be enough.  However the whole move coloring as motivated in commit
2e2d5ac (diff.c: color moved lines differently, 2017-06-30), brought
up the notion of the reviewer being able to trust the move of a "block".

As there are languages such as python, which depend on proper relative
indentation for the control flow of the program, ignoring any white space
change in a block would not uphold the promises of 2e2d5ac that allows
reviewers to pay less attention to the inside of a block, as inside
the reviewer wants to assume the same program flow.

This new mode of white space ignorance will take this into account and will
only allow the same white space changes per line in each block. This patch
even allows only for the same change at the beginning of the lines.

As this is a white space mode, it is made exclusive to other white space
modes in the move detection.

This patch brings some challenges, related to the detection of blocks.
We need a wide net to catch the possible moved lines, but then need to
narrow down to check if the blocks are still intact. Consider this
example (ignoring block sizes):

 - A
 - B
 - C
 +    A
 +    B
 +    C

At the beginning of a block when checking if there is a counterpart
for A, we have to ignore all space changes. However at the following
lines we have to check if the indent change stayed the same.

Checking if the indentation change did stay the same, is done by computing
the indentation change by the difference in line length, and then assume
the change is only in the beginning of the longer line, the common tail
is the same. That is why the test contains lines like:

 - <TAB> A
 ...
 + A <TAB>
 ...

As the first line starting a block is caught using a compare function that
ignores white spaces unlike the rest of the block, where the white space
delta is taken into account for the comparison, we also have to think about
the following situation:

 - A
 - B
 -   A
 -   B
 +    A
 +    B
 +      A
 +      B

When checking if the first A (both in the + and - lines) is a start of
a block, we have to check all 'A' and record all the white space deltas
such that we can find the example above to be just one block that is
indented.

Signed-off-by: Stefan Beller <sbeller@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-07-19 12:02:54 -07:00
Stefan Beller b3095712f9 diff.c: decouple white space treatment from move detection algorithm
In the original implementation of the move detection logic the choice for
ignoring white space changes is the same for the move detection as it is
for the regular diff.  Some cases came up where different treatment would
have been nice.

Allow the user to specify that white space should be ignored differently
during detection of moved lines than during generation of added and removed
lines. This is done by providing analogs to the --ignore-space-at-eol,
-b, and -w options by introducing the option --color-moved-ws=<modes>
with the modes named "ignore-space-at-eol", "ignore-space-change" and
"ignore-all-space", which is used only during the move detection phase.

As we change the default, we'll adjust the tests.

For now we do not infer any options to treat white spaces in the move
detection from the generic white space options given to diff.
This can be tuned later to reasonable default.

As we plan on adding more white space related options in a later patch,
that interferes with the current white space options, use a flag field
and clamp it down to  XDF_WHITESPACE_FLAGS, as that (a) allows to easily
check at parse time if we give invalid combinations and (b) can reuse
parts of this patch.

By having the white space treatment in its own option, we'll also
make it easier for a later patch to have an config option for
spaces in the move detection.

Signed-off-by: Stefan Beller <sbeller@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-07-17 11:25:31 -07:00
Stefan Beller 51da15eb23 diff.c: add a blocks mode for moved code detection
The new "blocks" mode provides a middle ground between plain and zebra.
It is as intuitive (few colors) as plain, but still has the requirement
for a minimum of lines/characters to count a block as moved.

Suggested-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
 (https://public-inbox.org/git/87o9j0uljo.fsf@evledraar.gmail.com/)
Signed-off-by: Stefan Beller <sbeller@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-07-17 11:25:31 -07:00
Ben Peart 85b460305c merge: add merge.renames config setting
Add the ability to control rename detection for merge via a config setting.
This setting behaves the same and defaults to the value of diff.renames but only
applies to merge.

Reviewed-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Helped-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Ben Peart <benpeart@microsoft.com>
Reviewed-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-05-08 16:19:41 +09:00
Junio C Hamano 868f7d2338 Merge branch 'nd/diff-stat-with-summary'
"git diff" and friends learned "--compact-summary" that shows the
information usually given with the "--summary" option on the same
line as the diffstat output of the "--stat" option (which saves
vertical space and keeps info on a single path at the same place).

* nd/diff-stat-with-summary:
  diff: add --compact-summary
  diff.c: refactor pprint_rename() to use strbuf
2018-03-14 12:01:02 -07:00
Nguyễn Thái Ngọc Duy ddf88fa616 diff: add --compact-summary
Certain information is currently shown with --summary, but when used
in combination with --stat it's a bit hard to read since info of the
same file is in two places (--stat and --summary).

On top of that, commits that add or remove files double the number of
display lines, which could be a lot if you add or remove a lot of
files.

--compact-summary embeds most of --summary back in --stat in the
little space between the file name part and the graph line, e.g. with
commit 0433d533f1:

   Documentation/merge-config.txt         |  4 +
   builtin/merge.c                        |  2 +
   ...-pull-verify-signatures.sh (new +x) | 81 ++++++++++++++
   t/t7612-merge-verify-signatures.sh     | 45 ++++++++
   4 files changed, 132 insertions(+)

It helps both condensing information and saving some text
space. What's new in diffstat is:

- A new 0644 file is shown as (new)
- A new 0755 file is shown as (new +x)
- A new symlink is shown as (new +l)
- A deleted file is shown as (gone)
- A mode change adding executable bit is shown as (mode +x)
- A mode change removing it is shown as (mode -x)

Note that --compact-summary does not contain all the information
--summary provides. Rewrite percentage is not shown but it could be
added later, like R50% or C20%.

Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-02-27 15:22:47 -08:00
Junio C Hamano c0d75f0e2e Merge branch 'sb/diff-blobfind-pickaxe'
"diff" family of commands learned "--find-object=<object-id>" option
to limit the findings to changes that involve the named object.

* sb/diff-blobfind-pickaxe:
  diff: use HAS_MULTI_BITS instead of counting bits manually
  diff: properly error out when combining multiple pickaxe options
  diffcore: add a pickaxe option to find a specific blob
  diff: introduce DIFF_PICKAXE_KINDS_MASK
  diff: migrate diff_flags.pickaxe_ignore_case to a pickaxe_opts bit
  diff.h: make pickaxe_opts an unsigned bit field
2018-01-23 13:16:37 -08:00
Stefan Beller 15af58c1ad diffcore: add a pickaxe option to find a specific blob
Sometimes users are given a hash of an object and they want to
identify it further (ex.: Use verify-pack to find the largest blobs,
but what are these? or [1])

One might be tempted to extend git-describe to also work with blobs,
such that `git describe <blob-id>` gives a description as
'<commit-ish>:<path>'.  This was implemented at [2]; as seen by the sheer
number of responses (>110), it turns out this is tricky to get right.
The hard part to get right is picking the correct 'commit-ish' as that
could be the commit that (re-)introduced the blob or the blob that
removed the blob; the blob could exist in different branches.

Junio hinted at a different approach of solving this problem, which this
patch implements. Teach the diff machinery another flag for restricting
the information to what is shown. For example:

    $ ./git log --oneline --find-object=v2.0.0:Makefile
    b2feb64309 Revert the whole "ask curl-config" topic for now
    47fbfded53 i18n: only extract comments marked with "TRANSLATORS:"

we observe that the Makefile as shipped with 2.0 was appeared in
v1.9.2-471-g47fbfded53 and in v2.0.0-rc1-5-gb2feb6430b.  The
reason why these commits both occur prior to v2.0.0 are evil
merges that are not found using this new mechanism.

[1] https://stackoverflow.com/questions/223678/which-commit-has-this-blob
[2] https://public-inbox.org/git/20171028004419.10139-1-sbeller@google.com/

Signed-off-by: Stefan Beller <sbeller@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-01-04 15:02:40 -08:00
Stefan Beller cf63051ada diff: introduce DIFF_PICKAXE_KINDS_MASK
Currently the check whether to perform pickaxing is done via checking
`diffopt->pickaxe`, which contains the command line argument that we
want to pickaxe for. Soon we'll introduce a new type of pickaxing, that
will not store anything in the `.pickaxe` field, so let's migrate the
check to be dependent on pickaxe_opts.

It is not enough to just replace the check for pickaxe by pickaxe_opts,
because flags might be set, but pickaxing was not requested ('-i').
To cope with that, introduce a mask to check only for the bits indicating
the modes of operation.

Signed-off-by: Stefan Beller <sbeller@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-01-04 15:02:40 -08:00
Stefan Beller c1ddc4610c diff: migrate diff_flags.pickaxe_ignore_case to a pickaxe_opts bit
Currently flags for pickaxing are found in different places. Unify the
flags into the `pickaxe_opts` field, which will contain any pickaxe related
flags.

Signed-off-by: Stefan Beller <sbeller@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-01-04 15:02:40 -08:00
Stefan Beller 929ed70a72 diff.h: make pickaxe_opts an unsigned bit field
This variable is used as a bit field[1], and as we are about to add more
fields, indicate its usage as a bit field by making it unsigned.

[1] containing the bits

    #define DIFF_PICKAXE_ALL	1
    #define DIFF_PICKAXE_REGEX	2
    #define DIFF_PICKAXE_KIND_S	4
    #define DIFF_PICKAXE_KIND_G	8

Signed-off-by: Stefan Beller <sbeller@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-01-04 15:02:40 -08:00
Jonathan Tan 2477ab2ea8 diff: support anchoring line(s)
Teach diff a new algorithm, one that attempts to prevent user-specified
lines from appearing as a deletion or addition in the end result. The
end user can use this by specifying "--anchored=<text>" one or more
times when using Git commands like "diff" and "show".

Signed-off-by: Jonathan Tan <jonathantanmy@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-11-28 10:40:04 +09:00
Junio C Hamano 8cc633286a Merge branch 'bw/diff-opt-impl-to-bitfields'
A single-word "unsigned flags" in the diff options is being split
into a structure with many bitfields.

* bw/diff-opt-impl-to-bitfields:
  diff: make struct diff_flags members lowercase
  diff: remove DIFF_OPT_CLR macro
  diff: remove DIFF_OPT_SET macro
  diff: remove DIFF_OPT_TST macro
  diff: remove touched flags
  diff: add flag to indicate textconv was set via cmdline
  diff: convert flags to be stored in bitfields
  add, reset: use DIFF_OPT_SET macro to set a diff flag
2017-11-09 14:31:27 +09:00
Junio C Hamano f4c214b529 Merge branch 'jk/revision-pruning-optim'
Pathspec-limited revision traversal was taught not to keep finding
unneeded differences once it knows two trees are different inside
given pathspec.

* jk/revision-pruning-optim:
  revision: quit pruning diff more quickly when possible
2017-11-06 14:24:26 +09:00
Brandon Williams 0d1e0e7801 diff: make struct diff_flags members lowercase
Now that the flags stored in struct diff_flags are being accessed
directly and not through macros, change all struct members from being
uppercase to lowercase.
This conversion is done using the following semantic patch:

	@@
	expression E;
	@@
	- E.RECURSIVE
	+ E.recursive

	@@
	expression E;
	@@
	- E.TREE_IN_RECURSIVE
	+ E.tree_in_recursive

	@@
	expression E;
	@@
	- E.BINARY
	+ E.binary

	@@
	expression E;
	@@
	- E.TEXT
	+ E.text

	@@
	expression E;
	@@
	- E.FULL_INDEX
	+ E.full_index

	@@
	expression E;
	@@
	- E.SILENT_ON_REMOVE
	+ E.silent_on_remove

	@@
	expression E;
	@@
	- E.FIND_COPIES_HARDER
	+ E.find_copies_harder

	@@
	expression E;
	@@
	- E.FOLLOW_RENAMES
	+ E.follow_renames

	@@
	expression E;
	@@
	- E.RENAME_EMPTY
	+ E.rename_empty

	@@
	expression E;
	@@
	- E.HAS_CHANGES
	+ E.has_changes

	@@
	expression E;
	@@
	- E.QUICK
	+ E.quick

	@@
	expression E;
	@@
	- E.NO_INDEX
	+ E.no_index

	@@
	expression E;
	@@
	- E.ALLOW_EXTERNAL
	+ E.allow_external

	@@
	expression E;
	@@
	- E.EXIT_WITH_STATUS
	+ E.exit_with_status

	@@
	expression E;
	@@
	- E.REVERSE_DIFF
	+ E.reverse_diff

	@@
	expression E;
	@@
	- E.CHECK_FAILED
	+ E.check_failed

	@@
	expression E;
	@@
	- E.RELATIVE_NAME
	+ E.relative_name

	@@
	expression E;
	@@
	- E.IGNORE_SUBMODULES
	+ E.ignore_submodules

	@@
	expression E;
	@@
	- E.DIRSTAT_CUMULATIVE
	+ E.dirstat_cumulative

	@@
	expression E;
	@@
	- E.DIRSTAT_BY_FILE
	+ E.dirstat_by_file

	@@
	expression E;
	@@
	- E.ALLOW_TEXTCONV
	+ E.allow_textconv

	@@
	expression E;
	@@
	- E.TEXTCONV_SET_VIA_CMDLINE
	+ E.textconv_set_via_cmdline

	@@
	expression E;
	@@
	- E.DIFF_FROM_CONTENTS
	+ E.diff_from_contents

	@@
	expression E;
	@@
	- E.DIRTY_SUBMODULES
	+ E.dirty_submodules

	@@
	expression E;
	@@
	- E.IGNORE_UNTRACKED_IN_SUBMODULES
	+ E.ignore_untracked_in_submodules

	@@
	expression E;
	@@
	- E.IGNORE_DIRTY_SUBMODULES
	+ E.ignore_dirty_submodules

	@@
	expression E;
	@@
	- E.OVERRIDE_SUBMODULE_CONFIG
	+ E.override_submodule_config

	@@
	expression E;
	@@
	- E.DIRSTAT_BY_LINE
	+ E.dirstat_by_line

	@@
	expression E;
	@@
	- E.FUNCCONTEXT
	+ E.funccontext

	@@
	expression E;
	@@
	- E.PICKAXE_IGNORE_CASE
	+ E.pickaxe_ignore_case

	@@
	expression E;
	@@
	- E.DEFAULT_FOLLOW_RENAMES
	+ E.default_follow_renames

Signed-off-by: Brandon Williams <bmwill@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-11-01 11:51:40 +09:00
Brandon Williams b2100e5291 diff: remove DIFF_OPT_CLR macro
Remove the `DIFF_OPT_CLR` macro and instead set the flags directly.
This conversion is done using the following semantic patch:

	@@
	expression E;
	identifier fld;
	@@
	- DIFF_OPT_CLR(&E, fld)
	+ E.flags.fld = 0

	@@
	type T;
	T *ptr;
	identifier fld;
	@@
	- DIFF_OPT_CLR(ptr, fld)
	+ ptr->flags.fld = 0

Signed-off-by: Brandon Williams <bmwill@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-11-01 11:51:30 +09:00
Brandon Williams 23dcf77f48 diff: remove DIFF_OPT_SET macro
Remove the `DIFF_OPT_SET` macro and instead set the flags directly.
This conversion is done using the following semantic patch:

	@@
	expression E;
	identifier fld;
	@@
	- DIFF_OPT_SET(&E, fld)
	+ E.flags.fld = 1

	@@
	type T;
	T *ptr;
	identifier fld;
	@@
	- DIFF_OPT_SET(ptr, fld)
	+ ptr->flags.fld = 1

Signed-off-by: Brandon Williams <bmwill@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-11-01 11:50:03 +09:00
Brandon Williams 3b69daed86 diff: remove DIFF_OPT_TST macro
Remove the `DIFF_OPT_TST` macro and instead access the flags directly.
This conversion is done using the following semantic patch:

	@@
	expression E;
	identifier fld;
	@@
	- DIFF_OPT_TST(&E, fld)
	+ E.flags.fld

	@@
	type T;
	T *ptr;
	identifier fld;
	@@
	- DIFF_OPT_TST(ptr, fld)
	+ ptr->flags.fld

Signed-off-by: Brandon Williams <bmwill@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-11-01 11:50:03 +09:00
Brandon Williams 25567af805 diff: remove touched flags
Now that the set of parallel touched flags are no longer being used,
remove them.

Signed-off-by: Brandon Williams <bmwill@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-11-01 11:50:02 +09:00
Brandon Williams afa73c5384 diff: add flag to indicate textconv was set via cmdline
git-show is unique in that it wants to use textconv by default except
for when it is showing blobs.  When asked to show a blob, show doesn't
want to use textconv unless the user explicitly requested that it be
used by providing the command line flag '--textconv'.

Currently this is done by using a parallel set of 'touched' flags which
get set every time a particular flag is set or cleared.  In a future
patch we want to eliminate this parallel set of flags so instead of
relying on if the textconv flag has been touched, add a new flag
'TEXTCONV_SET_VIA_CMDLINE' which is only set if textconv is set to true
via the command line.

Signed-off-by: Brandon Williams <bmwill@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-11-01 11:50:02 +09:00
Brandon Williams 02f2f56bc3 diff: convert flags to be stored in bitfields
We cannot add many more flags to the diff machinery due to the
limitations of the number of flags that can be stored in a single
unsigned int.  In order to allow for more flags to be added to the diff
machinery in the future this patch converts the flags to be stored in
bitfields in 'struct diff_flags'.

Signed-off-by: Brandon Williams <bmwill@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-11-01 11:50:02 +09:00
Jeff King a937b37e76 revision: quit pruning diff more quickly when possible
When the revision traversal machinery is given a pathspec,
we must compute the parent-diff for each commit to determine
which ones are TREESAME. We set the QUICK diff flag to avoid
looking at more entries than we need; we really just care
whether there are any changes at all.

But there is one case where we want to know a bit more: if
--remove-empty is set, we care about finding cases where the
change consists only of added entries (in which case we may
prune the parent in try_to_simplify_commit()). To cover that
case, our file_add_remove() callback does not quit the diff
upon seeing an added entry; it keeps looking for other types
of entries.

But this means when --remove-empty is not set (and it is not
by default), we compute more of the diff than is necessary.
You can see this in a pathological case where a commit adds
a very large number of entries, and we limit based on a
broad pathspec. E.g.:

  perl -e '
    chomp(my $blob = `git hash-object -w --stdin </dev/null`);
    for my $a (1..1000) {
      for my $b (1..1000) {
        print "100644 $blob\t$a/$b\n";
      }
    }
  ' | git update-index --index-info
  git commit -qm add

  git rev-list HEAD -- .

This case takes about 100ms now, but after this patch only
needs 6ms. That's not a huge improvement, but it's easy to
get and it protects us against even more pathological cases
(e.g., going from 1 million to 10 million files would take
ten times as long with the current code, but not increase at
all after this patch).

This is reported to minorly speed-up pathspec limiting in
real world repositories (like the 100-million-file Windows
repository), but probably won't make a noticeable difference
outside of pathological setups.

This patch actually covers the case without --remove-empty,
and the case where we see only deletions. See the in-code
comment for details.

Note that we have to add a new member to the diff_options
struct so that our callback can see the value of
revs->remove_empty_trees. This callback parameter could be
passed to the "add_remove" and "change" callbacks, but
there's not much point. They already receive the
diff_options struct, and doing it this way avoids having to
update the function signature of the other callbacks
(arguably the format_callback and output_prefix functions
could benefit from the same simplification).

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-10-14 11:43:49 +09:00
Jonathan Tan f0b8fb6e59 diff: define block by number of alphanumeric chars
The existing behavior of diff --color-moved=zebra does not define the
minimum size of a block at all, instead relying on a heuristic applied
later to filter out sets of adjacent moved lines that are shorter than 3
lines long. This can be confusing, because a block could thus be colored
as moved at the source but not at the destination (or vice versa),
depending on its neighbors.

Instead, teach diff that the minimum size of a block is 20 alphanumeric
characters, the same heuristic used by "git blame". This allows diff to
still exclude uninteresting lines appearing on their own (such as those
solely consisting of one or a few closing braces), as was the intention
of the adjacent-moved-line heuristic.

This requires a change in some tests in that some of their lines are no
longer considered to be part of a block, because they are too short.

Signed-off-by: Jonathan Tan <jonathantanmy@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-08-16 11:44:00 -07:00
Stefan Beller 86b452e276 diff.c: add dimming to moved line detection
Any lines inside a moved block of code are not interesting. Boundaries
of blocks are only interesting if they are next to another block of moved
code.

Signed-off-by: Stefan Beller <sbeller@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-06-30 13:59:42 -07:00
Stefan Beller 176841f0c9 diff.c: color moved lines differently, plain mode
Add the 'plain' mode for move detection of code. This omits the checking
for adjacent blocks, so it is not as useful. If you have a lot of the
same blocks moved in the same patch, the 'Zebra' would end up slow as it
is O(n^2) (n is number of same blocks). So this may be useful there and
is generally easy to add. Instead be very literal at the move detection,
do not skip over short blocks here.

Signed-off-by: Stefan Beller <sbeller@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-06-30 13:59:42 -07:00
Stefan Beller 2e2d5ac184 diff.c: color moved lines differently
When a patch consists mostly of moving blocks of code around, it can
be quite tedious to ensure that the blocks are moved verbatim, and not
undesirably modified in the move. To that end, color blocks that are
moved within the same patch differently. For example (OM, del, add,
and NM are different colors):

    [OM]  -void sensitive_stuff(void)
    [OM]  -{
    [OM]  -        if (!is_authorized_user())
    [OM]  -                die("unauthorized");
    [OM]  -        sensitive_stuff(spanning,
    [OM]  -                        multiple,
    [OM]  -                        lines);
    [OM]  -}

           void another_function()
           {
    [del] -        printf("foo");
    [add] +        printf("bar");
           }

    [NM]  +void sensitive_stuff(void)
    [NM]  +{
    [NM]  +        if (!is_authorized_user())
    [NM]  +                die("unauthorized");
    [NM]  +        sensitive_stuff(spanning,
    [NM]  +                        multiple,
    [NM]  +                        lines);
    [NM]  +}

However adjacent blocks may be problematic. For example, in this
potentially malicious patch, the swapping of blocks can be spotted:

    [OM]  -void sensitive_stuff(void)
    [OM]  -{
    [OMA] -        if (!is_authorized_user())
    [OMA] -                die("unauthorized");
    [OM]  -        sensitive_stuff(spanning,
    [OM]  -                        multiple,
    [OM]  -                        lines);
    [OMA] -}

           void another_function()
           {
    [del] -        printf("foo");
    [add] +        printf("bar");
           }

    [NM]  +void sensitive_stuff(void)
    [NM]  +{
    [NMA] +        sensitive_stuff(spanning,
    [NMA] +                        multiple,
    [NMA] +                        lines);
    [NM]  +        if (!is_authorized_user())
    [NM]  +                die("unauthorized");
    [NMA] +}

If the moved code is larger, it is easier to hide some permutation in the
code, which is why some alternative coloring is needed.

This patch implements the first mode:
* basic alternating 'Zebra' mode
  This conveys all information needed to the user.  Defer customization to
  later patches.

First I implemented an alternative design, which would try to fingerprint
a line by its neighbors to detect if we are in a block or at the boundary.
This idea iss error prone as it inspected each line and its neighboring
lines to determine if the line was (a) moved and (b) if was deep inside
a hunk by having matching neighboring lines. This is unreliable as the
we can construct hunks which have equal neighbors that just exceed the
number of lines inspected. (Think of 'AXYZBXYZCXYZD..' with each letter
as a line, that is permutated to AXYZCXYZBXYZD..').

Instead this provides a dynamic programming greedy algorithm that finds
the largest moved hunk and then has several modes on highlighting bounds.

A note on the options '--submodule=diff' and '--color-words/--word-diff':
In the conversion to use emit_line in the prior patches both submodules
as well as word diff output carefully chose to call emit_line with sign=0.
All output with sign=0 is ignored for move detection purposes in this
patch, such that no weird looking output will be generated for these
cases. This leads to another thought: We could pass on '--color-moved' to
submodules such that they color up moved lines for themselves. If we'd do
so only line moves within a repository boundary are marked up.

It is useful to have moved lines colored, but there are annoying corner
cases, such as a single line moved, that is very common. For example
in a typical patch of C code, we have closing braces that end statement
blocks or functions.

While it is technically true that these lines are moved as they show up
elsewhere, it is harmful for the review as the reviewers attention is
drawn to such a minor side annoyance.

For now let's have a simple solution of hardcoding the number of
moved lines to be at least 3 before coloring them. Note, that the
length is applied across all blocks to find the 'lonely' blocks
that pollute new code, but do not interfere with a permutated
block where each permutation has less lines than 3.

Helped-by: Jonathan Tan <jonathantanmy@google.com>
Signed-off-by: Stefan Beller <sbeller@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-06-30 13:59:42 -07:00
Stefan Beller e6e045f803 diff.c: buffer all output if asked to
Introduce a new option 'emitted_symbols' in the struct diff_options which
controls whether all output is buffered up until all output is available.
It is set internally in diff.c when necessary.

We'll have a new struct 'emitted_string' in diff.c which will be used to
buffer each line.  The emitted_string will duplicate the memory of the
line to buffer as that is easiest to reason about for now. In a future
patch we may want to decrease the memory usage by not duplicating all
output for buffering but rather we may want to store offsets into the
file or in case of hunk descriptions such as the similarity score, we
could just store the relevant number and reproduce the text later on.

This approach was chosen as a first step because it is quite simple
compared to the alternative with less memory footprint.

emit_diff_symbol factors out the emission part and depending on the
diff_options->emitted_symbols the emission will be performed directly
when calling emit_diff_symbol or after the whole process is done, i.e.
by buffering we have add the possibility for a second pass over the
whole output before doing the actual output.

In 6440d34 (2012-03-14, diff: tweak a _copy_ of diff_options with
word-diff) we introduced a duplicate diff options struct for word
emissions as we may have different regex settings in there.
When buffering the output, we need to operate on just one buffer,
so we have to copy back the emissions of the word buffer into the
main buffer.

Unconditionally enable output via buffer in this patch as it yields
a great opportunity for testing, i.e. all the diff tests from the
test suite pass without having reordering issues (i.e. only parts
of the output got buffered, and we forgot to buffer other parts).
The test suite passes, which gives confidence that we converted all
functions to use emit_string for output.

Signed-off-by: Stefan Beller <sbeller@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-06-30 13:13:02 -07:00
Stefan Beller 0911c475c8 diff.c: convert show_stats to use emit_diff_symbol
We call print_stat_summary from builtin/apply, so we still
need the version with a file pointer, so introduce
print_stat_summary_0 that uses emit_string machinery and
keep print_stat_summary with the same arguments around.

Signed-off-by: Stefan Beller <sbeller@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-06-30 13:13:02 -07:00
Stefan Beller f3597138df submodule.c: migrate diff output to use emit_diff_symbol
As the submodule process is no longer attached to the same file pointer
'o->file' as the superprojects process, there is a different result in
color.c::check_auto_color. That is why we need to pass coloring explicitly,
such that the submodule coloring decision will be made by the child process
processing the submodule. Only DIFF_SYMBOL_SUBMODULE_PIPETHROUGH contains
color, the other symbols are for embedding the submodule output into the
superprojects output.

Remove the colors from the function signatures, as all the coloring
decisions will be made either inside the child process or the final
emit_diff_symbol, but not in the functions driving the submodule diff.

Signed-off-by: Stefan Beller <sbeller@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-06-30 13:13:02 -07:00
Stefan Beller 091f8e28b4 diff.c: migrate emit_line_checked to use emit_diff_symbol
Add a new flags field to emit_diff_symbol, that will be used by
context lines for:
* white space rules that are applicable (The first 12 bits)
  Take a note in cahe.c as well, when this ws rules are extended we have
  to fix the bits in the flags field.
* how the rules are evaluated (actually this double encodes the sign
  of the line, but the code is easier to keep this way, bits 13,14,15)
* if the line a blank line at EOF (bit 16)

The check if new lines need to be marked up as extra lines at the end of
file, is now done unconditionally. That should be ok, as
'new_blank_line_at_eof' has a quick early return.

Signed-off-by: Stefan Beller <sbeller@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-06-30 13:13:01 -07:00
Junio C Hamano a6f38c109b Merge branch 'bw/object-id'
Conversion from uchar[20] to struct object_id continues.

* bw/object-id: (33 commits)
  diff: rename diff_fill_sha1_info to diff_fill_oid_info
  diffcore-rename: use is_empty_blob_oid
  tree-diff: convert path_appendnew to object_id
  tree-diff: convert diff_tree_paths to struct object_id
  tree-diff: convert try_to_follow_renames to struct object_id
  builtin/diff-tree: cleanup references to sha1
  diff-tree: convert diff_tree_sha1 to struct object_id
  notes-merge: convert write_note_to_worktree to struct object_id
  notes-merge: convert verify_notes_filepair to struct object_id
  notes-merge: convert find_notes_merge_pair_ps to struct object_id
  notes-merge: convert merge_from_diffs to struct object_id
  notes-merge: convert notes_merge* to struct object_id
  tree-diff: convert diff_root_tree_sha1 to struct object_id
  combine-diff: convert find_paths_* to struct object_id
  combine-diff: convert diff_tree_combined to struct object_id
  diff: convert diff_flush_patch_id to struct object_id
  patch-ids: convert to struct object_id
  diff: finish conversion for prepare_temp_file to struct object_id
  diff: convert reuse_worktree_file to struct object_id
  diff: convert fill_filespec to struct object_id
  ...
2017-06-19 12:38:44 -07:00
Brandon Williams fda94b416e tree-diff: convert diff_tree_paths to struct object_id
Signed-off-by: Brandon Williams <bmwill@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-06-05 11:23:58 +09:00
Brandon Williams 66f414f885 diff-tree: convert diff_tree_sha1 to struct object_id
Signed-off-by: Brandon Williams <bmwill@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-06-05 11:23:58 +09:00
Junio C Hamano 583c6a2295 Merge branch 'js/blame-lib'
The internal logic used in "git blame" has been libified to make it
easier to use by cgit.

* js/blame-lib: (29 commits)
  blame: move entry prepend to libgit
  blame: move scoreboard setup to libgit
  blame: move scoreboard-related methods to libgit
  blame: move fake-commit-related methods to libgit
  blame: move origin-related methods to libgit
  blame: move core structures to header
  blame: create entry prepend function
  blame: create scoreboard setup function
  blame: create scoreboard init function
  blame: rework methods that determine 'final' commit
  blame: wrap blame_sort and compare_blame_final
  blame: move progress updates to a scoreboard callback
  blame: make sanity_check use a callback in scoreboard
  blame: move no_whole_file_rename flag to scoreboard
  blame: move xdl_opts flags to scoreboard
  blame: move show_root flag to scoreboard
  blame: move reverse flag to scoreboard
  blame: move contents_from to scoreboard
  blame: move copy/move thresholds to scoreboard
  blame: move stat counters to scoreboard
  ...
2017-06-05 09:18:12 +09:00
Brandon Williams 7b8dea0c75 tree-diff: convert diff_root_tree_sha1 to struct object_id
Signed-off-by: Brandon Williams <bmwill@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-06-02 09:36:30 +09:00
Brandon Williams b9acf54dbd combine-diff: convert diff_tree_combined to struct object_id
Signed-off-by: Brandon Williams <bmwill@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-06-02 09:36:07 +09:00
Brandon Williams bd25f28876 diff: convert diff_flush_patch_id to struct object_id
Signed-off-by: Brandon Williams <bmwill@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-06-02 09:36:07 +09:00
Brandon Williams 94a0097a41 diff: convert diff_change to struct object_id
Convert diff_change to take a struct object_id.  In addition convert the
function pointer type 'change_fn_t' to also take a struct object_id.

Signed-off-by: Brandon Williams <bmwill@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-06-02 09:36:07 +09:00
Brandon Williams c26022ea8f diff: convert diff_addremove to struct object_id
Convert diff_addremove to take a struct object_id.  In addtion convert
the function pointer type 'add_remove_fn_t' to also take a struct
object_id.

Signed-off-by: Brandon Williams <bmwill@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-06-02 09:36:07 +09:00
Jeff Smith 3a35cb2ea8 blame: move textconv_object with related functions
textconv_object is used in places other than blame.c and should be moved
to a more appropriate location.  Other textconv related functions are
located in diff.c so that seems as good a place as any.

Signed-off-by: Jeff Smith <whydoubt@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-05-24 15:41:50 +09:00
brian m. carlson 944cffbd18 diff-lib: convert do_diff_cache to struct object_id
This is needed to convert parse_tree_indirect.

Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-05-08 15:12:58 +09:00
brian m. carlson 910650d2f8 Rename sha1_array to oid_array
Since this structure handles an array of object IDs, rename it to struct
oid_array.  Also rename the accessor functions and the initialization
constant.

This commit was produced mechanically by providing non-Documentation
files to the following Perl one-liners:

    perl -pi -E 's/struct sha1_array/struct oid_array/g'
    perl -pi -E 's/\bsha1_array_/oid_array_/g'
    perl -pi -E 's/SHA1_ARRAY_INIT/OID_ARRAY_INIT/g'

Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-03-31 08:33:56 -07:00
Junio C Hamano 650360210a Merge branch 'nd/ita-empty-commit'
When new paths were added by "git add -N" to the index, it was
enough to circumvent the check by "git commit" to refrain from
making an empty commit without "--allow-empty".  The same logic
prevented "git status" to show such a path as "new file" in the
"Changes not staged for commit" section.

* nd/ita-empty-commit:
  commit: don't be fooled by ita entries when creating initial commit
  commit: fix empty commit creation when there's no changes but ita entries
  diff: add --ita-[in]visible-in-index
  diff-lib: allow ita entries treated as "not yet exist in index"
2016-10-27 14:58:50 -07:00
Jeff King d6cece51b8 diff_aligned_abbrev: use "struct oid"
Since we're modifying this function anyway, it's a good time
to update it to the more modern "struct oid". We can also
drop some of the magic numbers in favor of GIT_SHA1_HEXSZ,
along with some descriptive comments.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2016-10-26 13:30:51 -07:00
Jeff King d5e3b01e5b diff_unique_abbrev: rename to diff_aligned_abbrev
The word "align" describes how the function actually differs
from find_unique_abbrev, and will make it less confusing
when we add more diff-specific abbrevation functions that do
not do this alignment.

Since this is a globally available function, let's also move
its descriptive comment to the header file, where we
typically document function interfaces.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2016-10-26 13:30:51 -07:00
Nguyễn Thái Ngọc Duy 018ec3c820 commit: fix empty commit creation when there's no changes but ita entries
If i-t-a entries are present and there is no change between the index
and HEAD i-t-a entries, index_differs_from() still returns "dirty, new
entries" (aka, the resulting commit is not empty), but cache-tree will
skip i-t-a entries and produce the exact same tree of current
commit.

index_differs_from() is supposed to catch this so we can abort
git-commit (unless --no-empty is specified). Update it to optionally
ignore i-t-a entries when doing a diff between the index and HEAD so
that it would return "no change" in this case and abort commit.

Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2016-10-24 10:48:23 -07:00
Nguyễn Thái Ngọc Duy 425a28e0a4 diff-lib: allow ita entries treated as "not yet exist in index"
When comparing the index and the working tree to show which paths are
new, and comparing the tree recorded in the HEAD and the index to see if
committing the contents recorded in the index would result in an empty
commit, we would want the former comparison to say "these are new paths"
and the latter to say "there is no change" for paths that are marked as
intent-to-add.

We made a similar attempt at d95d728a ("diff-lib.c: adjust position of
i-t-a entries in diff", 2015-03-16), which redefined the semantics of
these two comparison modes globally, which was a disaster and had to be
reverted at 78cc1a54 ("Revert "diff-lib.c: adjust position of i-t-a
entries in diff"", 2015-06-23).

To make sure we do not repeat the same mistake, introduce a new internal
diffopt option so that this different semantics can be asked for only by
callers that ask it, while making sure other unaudited callers will get
the same comparison result.

Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2016-10-24 10:47:28 -07:00
Junio C Hamano b7af6ae5cf Merge branch 'mh/diff-indent-heuristic'
Output from "git diff" can be made easier to read by selecting
which lines are common and which lines are added/deleted
intelligently when the lines before and after the changed section
are the same.  A command line option is added to help with the
experiment to find a good heuristics.

* mh/diff-indent-heuristic:
  blame: honor the diff heuristic options and config
  parse-options: add parse_opt_unknown_cb()
  diff: improve positioning of add/delete blocks in diffs
  xdl_change_compact(): introduce the concept of a change group
  recs_match(): take two xrecord_t pointers as arguments
  is_blank_line(): take a single xrecord_t as argument
  xdl_change_compact(): only use heuristic if group can't be matched
  xdl_change_compact(): fix compaction heuristic to adjust ixo
2016-09-26 16:09:16 -07:00
Michael Haggerty 5b162879e9 blame: honor the diff heuristic options and config
Teach "git blame" and "git annotate" the --compaction-heuristic and
--indent-heuristic options that are now supported by "git diff".

Also teach them to honor the `diff.compactionHeuristic` and
`diff.indentHeuristic` configuration options.

It would be conceivable to introduce separate configuration options for
"blame" and "annotate"; for example `blame.compactionHeuristic` and
`blame.indentHeuristic`. But it would be confusing to users if blame
output is inconsistent with diff output, so it makes more sense for them
to respect the same configuration.

Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2016-09-19 10:25:11 -07:00
Junio C Hamano 305d7f1339 Merge branch 'jk/diff-submodule-diff-inline'
The "git diff --submodule={short,log}" mechanism has been enhanced
to allow "--submodule=diff" to show the patch between the submodule
commits bound to the superproject.

* jk/diff-submodule-diff-inline:
  diff: teach diff to display submodule difference with an inline diff
  submodule: refactor show_submodule_summary with helper function
  submodule: convert show_submodule_summary to use struct object_id *
  allow do_submodule_path to work even if submodule isn't checked out
  diff: prepare for additional submodule formats
  graph: add support for --line-prefix on all graph-aware output
  diff.c: remove output_prefix_length field
  cache: add empty_tree_oid object and helper function
2016-09-12 15:34:31 -07:00
Jacob Keller fd47ae6a5b diff: teach diff to display submodule difference with an inline diff
Teach git-diff and friends a new format for displaying the difference
of a submodule. The new format is an inline diff of the contents of the
submodule between the commit range of the update. This allows the user
to see the actual code change caused by a submodule update.

Add tests for the new format and option.

Signed-off-by: Jacob Keller <jacob.keller@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2016-08-31 18:07:10 -07:00
Jacob Keller 61cfbc054d diff: prepare for additional submodule formats
A future patch will add a new format for displaying the difference of
a submodule. Make it easier by changing how we store the current
selected format. Replace the DIFF_OPT flag with an enumeration, as each
format will be mutually exclusive.

Signed-off-by: Jacob Keller <jacob.keller@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2016-08-31 18:07:09 -07:00
Jacob Keller 660e113ce1 graph: add support for --line-prefix on all graph-aware output
Add an extension to git-diff and git-log (and any other graph-aware
displayable output) such that "--line-prefix=<string>" will print the
additional line-prefix on every line of output.

To make this work, we have to fix a few bugs in the graph API that force
graph_show_commit_msg to be used only when you have a valid graph.
Additionally, we extend the default_diff_output_prefix handler to work
even when no graph is enabled.

This is somewhat of a hack on top of the graph API, but I think it
should be acceptable here.

This will be used by a future extension of submodule display which
displays the submodule diff as the actual diff between the pre and post
commit in the submodule project.

Add some tests for both git-log and git-diff to ensure that the prefix
is honored correctly.

Signed-off-by: Jacob Keller <jacob.keller@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2016-08-31 18:07:09 -07:00
Junio C Hamano cd48dadb8d diff.c: remove output_prefix_length field
"diff/log --stat" has a logic that determines the display columns
available for the diffstat part of the output and apportions it for
pathnames and diffstat graph automatically.

5e71a84a (Add output_prefix_length to diff_options, 2012-04-16)
added the output_prefix_length field to diff_options structure to
allow this logic to subtract the display columns used for the
history graph part from the total "terminal width"; this matters
when the "git log --graph -p" option is in use.

The field must be set to the number of display columns needed to
show the output from the output_prefix() callback, which is error
prone.  As there is only one user of the field, and the user has the
actual value of the prefix string, let's get rid of the field and
have the user count the display width itself.

Signed-off-by: Junio C Hamano <gitster@pobox.com>
2016-08-31 18:07:08 -07:00
Kevin Willford 3e8e32c32e patch-ids: add flag to create the diff patch id using header only data
This will allow a diff patch id to be created using only the header data
so that the contents of the file will not have to be loaded.

Signed-off-by: Kevin Willford <kcwillford@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2016-07-29 14:10:01 -07:00
Junio C Hamano 5d2a30d7d8 Merge branch 'mm/diff-renames-default'
The end-user facing Porcelain level commands like "diff" and "log"
now enables the rename detection by default.

* mm/diff-renames-default:
  diff: activate diff.renames by default
  log: introduce init_log_defaults()
  t: add tests for diff.renames (true/false/unset)
  t4001-diff-rename: wrap file creations in a test
  Documentation/diff-config: fix description of diff.renames
2016-04-03 10:29:22 -07:00
Junio C Hamano 11529ecec9 Merge branch 'jk/tighten-alloc'
Update various codepaths to avoid manually-counted malloc().

* jk/tighten-alloc: (22 commits)
  ewah: convert to REALLOC_ARRAY, etc
  convert ewah/bitmap code to use xmalloc
  diff_populate_gitlink: use a strbuf
  transport_anonymize_url: use xstrfmt
  git-compat-util: drop mempcpy compat code
  sequencer: simplify memory allocation of get_message
  test-path-utils: fix normalize_path_copy output buffer size
  fetch-pack: simplify add_sought_entry
  fast-import: simplify allocation in start_packfile
  write_untracked_extension: use FLEX_ALLOC helper
  prepare_{git,shell}_cmd: use argv_array
  use st_add and st_mult for allocation size computation
  convert trivial cases to FLEX_ARRAY macros
  use xmallocz to avoid size arithmetic
  convert trivial cases to ALLOC_ARRAY
  convert manual allocations to argv_array
  argv-array: add detach function
  add helpers for allocating flex-array structs
  harden REALLOC_ARRAY and xcalloc against size_t overflow
  tree-diff: catch integer overflow in combine_diff_path allocation
  ...
2016-02-26 13:37:16 -08:00
Junio C Hamano 3ed26a44b3 Merge branch 'jk/more-comments-on-textconv'
The memory ownership rule of fill_textconv() API, which was a bit
tricky, has been documented a bit better.

* jk/more-comments-on-textconv:
  diff: clarify textconv interface
2016-02-26 13:37:15 -08:00
Matthieu Moy 5404c116aa diff: activate diff.renames by default
Rename detection is a very convenient feature, and new users shouldn't
have to dig in the documentation to benefit from it.

Potential objections to activating rename detection are that it
sometimes fail, and it is sometimes slow. But rename detection is
already activated by default in several cases like "git status" and "git
merge", so activating diff.renames does not fundamentally change the
situation. When the rename detection fails, it now fails consistently
between "git diff" and "git status".

This setting does not affect plumbing commands, hence well-written
scripts will not be affected.

Signed-off-by: Matthieu Moy <Matthieu.Moy@imag.fr>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2016-02-25 11:31:02 -08:00
Jeff King a64e6a44c6 diff: clarify textconv interface
The memory allocation scheme for the textconv interface is a
bit tricky, and not well documented. It was originally
designed as an internal part of diff.c (matching
fill_mmfile), but gradually was made public.

Refactoring it is difficult, but we can at least improve the
situation by documenting the intended flow and enforcing it
with an in-code assertion.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2016-02-22 10:40:35 -08:00
Jeff King 5b442c4f27 tree-diff: catch integer overflow in combine_diff_path allocation
A combine_diff_path struct has two "flex" members allocated
alongside the struct: a string to hold the pathname, and an
array of parent pointers. We use an "int" to compute this,
meaning we may easily overflow it if the pathname is
extremely long.

We can fix this by using size_t, and checking for overflow
with the st_add helper.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2016-02-19 09:40:37 -08:00