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Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
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For --rename-empty, see 90d43b0768 (teach diffcore-rename to
optionally ignore empty content - 2012-03-22) for more information.
Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
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This also validates that the user specifies a single character in
--output-indicator-*, not a string.
Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
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Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
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Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
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The -G<regex> option of log looks for the differences whose patch text
contains added/removed lines that match regex.
Currently -G looks also into patches of binary files (which
according to [1]) is binary as well.
This has a couple of issues:
- It makes the pickaxe search slow. In a proprietary repository of the
author with only ~5500 commits and a total .git size of ~300MB
searching takes ~13 seconds
$time git log -Gwave > /dev/null
real 0m13,241s
user 0m12,596s
sys 0m0,644s
whereas when we ignore binary files with this patch it takes ~4s
$time ~/devel/git/git log -Gwave > /dev/null
real 0m3,713s
user 0m3,608s
sys 0m0,105s
which is a speedup of more than fourfold.
- The internally used algorithm for generating patch text is based on
xdiff and its states in [1]
> The output format of the binary patch file is proprietary
> (and binary) and it is basically a collection of copy and insert
> commands [..]
which means that the current format could change once the internal
algorithm is changed as the format is not standardized. In addition
the git binary patch format used for preparing patches for git apply
is *different* from the xdiff format as can be seen by comparing
git log -p -a
commit 6e95bf4bafccf14650d02ab57f3affe669be10cf
Author: A U Thor <author@example.com>
Date: Thu Apr 7 15:14:13 2005 -0700
modify binary file
diff --git a/data.bin b/data.bin
index f414c84..edfeb6f 100644
--- a/data.bin
+++ b/data.bin
@@ -1,2 +1,4 @@
a
a^@a
+a
+a^@a
with git log --binary
commit 6e95bf4bafccf14650d02ab57f3affe669be10cf
Author: A U Thor <author@example.com>
Date: Thu Apr 7 15:14:13 2005 -0700
modify binary file
diff --git a/data.bin b/data.bin
index f414c84bd3aa25fa07836bb1fb73db784635e24b..edfeb6f501[..]
GIT binary patch
literal 12
QcmYe~N@Pgn0zx1O01)N^ZvX%Q
literal 6
NcmYe~N@Pgn0ssWg0XP5v
which seems unexpected.
To resolve these issues this patch makes -G<regex> ignore binary files
by default. Textconv filters are supported and also -a/--text for
getting the old and broken behaviour back.
The -S<block of text> option of log looks for differences that changes
the number of occurrences of the specified block of text (i.e.
addition/deletion) in a file. As we want to keep the current behaviour,
add a test to ensure it stays that way.
[1]: http://www.xmailserver.org/xdiff.html
Signed-off-by: Thomas Braun <thomas.braun@virtuell-zuhause.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
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One of the "diff --color-moved" mode "dimmed_zebra" that was named
in an unusual way has been deprecated and replaced by
"dimmed-zebra".
* es/diff-color-moved-fix:
diff: --color-moved: rename "dimmed_zebra" to "dimmed-zebra"
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"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
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The --color-moved "dimmed_zebra" mode (with an underscore) is an
anachronism. Most options and modes are hyphenated. It is more difficult
to type and somewhat more difficult to read than those which are
hyphenated. Therefore, rename it to "dimmed-zebra", and nominally
deprecate "dimmed_zebra".
Signed-off-by: Eric Sunshine <sunshine@sunshineco.com>
Reviewed-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
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Signed-off-by: Stefan Beller <sbeller@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
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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>
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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>
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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>
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Signed-off-by: Karthikeyan Singaravelan <tir.karthi@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
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Typofix.
* rd/diff-options-typofix:
diff-options.txt: fix minor typos, font inconsistencies, in docs
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Signed-off-by: Robert P. J. Day <rpjday@crashcourse.ca>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
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Docfix.
* en/doc-typoes:
Documentation: normalize spelling of 'normalised'
Documentation: fix several one-character-off spelling errors
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Signed-off-by: Elijah Newren <newren@gmail.com>
Reviewed-by: Stefan Beller <sbeller@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
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"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
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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>
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"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
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Doc update.
* jk/doc-diff-options:
docs/diff-options: clarify scope of diff-filter types
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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>
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The same document for "--diff-filter" is included by many
programs in the diff family. Because it mentions all
possible types (added, removed, etc), this may imply to the
reader that all types can be generated by a particular
command. But this isn't necessarily the case; "diff-files"
cannot generally produce an "Added" entry, since the diff is
limited to what is already in the index.
Let's make it clear that the list here is the full one, and
does not imply anything about what a particular invocation
may produce.
Note that conditionally including items (e.g., omitting
"Added" in the git-diff-files manpage) isn't the right
solution here for two reasons:
- The problem isn't diff-files, but doing an index to
working tree diff. "git diff" can do the same diff, but
also has other modes where "Added" does show up.
- The direction of the diff matters. Doing "diff-files -R"
can get you Added entries (but not Deleted ones).
So it's best just to explain that the set of available types
depends on the specific diff invocation.
Reported-by: John Cheng <johnlicheng@gmail.com>
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
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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>
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The "diff" family of commands learned to ignore differences in
carriage return at the end of line.
* jc/ignore-cr-at-eol:
diff: --ignore-cr-at-eol
xdiff: reassign xpparm_t.flags bits
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Doc update.
* cn/diff-indent-no-longer-is-experimental:
diff: --indent-heuristic is no longer experimental
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A new option --ignore-cr-at-eol tells the diff machinery to treat a
carriage-return at the end of a (complete) line as if it does not
exist.
Just like other "--ignore-*" options to ignore various kinds of
whitespace differences, this will help reviewing the real changes
you made without getting distracted by spurious CRLF<->LF conversion
made by your editor program.
Helped-by: Johannes Schindelin <Johannes.Schindelin@gmx.de>
[jch: squashed in command line completion by Dscho]
Signed-off-by: Junio C Hamano <gitster@pobox.com>
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Doc update.
* cn/diff-indent-no-longer-is-experimental:
diff: --indent-heuristic is no longer experimental
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This heuristic has been the default since 2.14 so we should not confuse our
users by saying that it's experimental and off by default.
Signed-off-by: Carlos Martín Nieto <cmn@dwim.me>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
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A handful of bugfixes and an improvement to "diff --color-moved".
* jt/diff-color-move-fix:
diff: define block by number of alphanumeric chars
diff: respect MIN_BLOCK_LENGTH for last block
diff: avoid redundantly clearing a flag
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"git diff" has been taught to optionally paint new lines that are
the same as deleted lines elsewhere differently from genuinely new
lines.
* sb/diff-color-move: (25 commits)
diff: document the new --color-moved setting
diff.c: add dimming to moved line detection
diff.c: color moved lines differently, plain mode
diff.c: color moved lines differently
diff.c: buffer all output if asked to
diff.c: emit_diff_symbol learns about DIFF_SYMBOL_SUMMARY
diff.c: emit_diff_symbol learns about DIFF_SYMBOL_STAT_SEP
diff.c: convert word diffing to use emit_diff_symbol
diff.c: convert show_stats to use emit_diff_symbol
diff.c: convert emit_binary_diff_body to use emit_diff_symbol
submodule.c: migrate diff output to use emit_diff_symbol
diff.c: emit_diff_symbol learns DIFF_SYMBOL_REWRITE_DIFF
diff.c: emit_diff_symbol learns about DIFF_SYMBOL_BINARY_FILES
diff.c: emit_diff_symbol learns DIFF_SYMBOL_HEADER
diff.c: emit_diff_symbol learns DIFF_SYMBOL_FILEPAIR_{PLUS, MINUS}
diff.c: emit_diff_symbol learns DIFF_SYMBOL_CONTEXT_INCOMPLETE
diff.c: emit_diff_symbol learns DIFF_SYMBOL_WORDS[_PORCELAIN]
diff.c: migrate emit_line_checked to use emit_diff_symbol
diff.c: emit_diff_symbol learns DIFF_SYMBOL_NO_LF_EOF
diff.c: emit_diff_symbol learns DIFF_SYMBOL_CONTEXT_FRAGINFO
...
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Doc update.
* ah/doc-wserrorhighlight:
doc: add missing values "none" and "default" for diff.wsErrorHighlight
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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>
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Doc update.
* ah/doc-wserrorhighlight:
doc: add missing values "none" and "default" for diff.wsErrorHighlight
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Signed-off-by: Anthony Sottile <asottile@umich.edu>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
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The values have eluded documentation so far. While at it streamline
the wording by grouping relevant parts together.
Signed-off-by: Andreas Heiduk <asheiduk@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
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Signed-off-by: Stefan Beller <sbeller@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
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Linking the description for pathname quoting to the configuration
variable "core.quotePath" removes inconstistent and incomplete
sections while also giving two hints how to deal with it: Either with
"-c core.quotePath=false" or with "-z".
Signed-off-by: Andreas Heiduk <asheiduk@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
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Documentation fix.
* rh/diff-orderfile-doc:
diff: document the format of the -O (diff.orderFile) file
diff: document behavior of relative diff.orderFile
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Signed-off-by: Richard Hansen <hansenr@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
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The --inter-hunk-context= option was added in commit 6d0e674a5754
("diff: add option to show context between close hunks"). This patch
allows configuring a default for this option.
Signed-off-by: Vegard Nossum <vegard.nossum@oracle.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
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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"
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"git diff/log --ws-error-highlight=<kind>" lacked the corresponding
configuration variable to set it by default.
* jc/ws-error-highlight:
diff: introduce diff.wsErrorHighlight option
diff.c: move ws-error-highlight parsing helpers up
diff.c: refactor parse_ws_error_highlight()
t4015: split out the "setup" part of ws-error-highlight test
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The option --ita-invisible-in-index exposes the "ita_invisible_in_index"
diff flag to outside to allow easier experimentation with this new mode.
The "plan" is to make --ita-invisible-in-index default to keep consistent
behavior with 'status' and 'commit', but a bunch other commands like
'apply', 'merge', 'reset'.... need to be taken into consideration as well.
Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
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With the preparatory steps, it has become trivial to teach the
system a new diff.wsErrorHighlight configuration that gives the
default value for --ws-error-highlight command line option.
Signed-off-by: Junio C Hamano <gitster@pobox.com>
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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
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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>
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Some groups of added/deleted lines in diffs can be slid up or down,
because lines at the edges of the group are not unique. Picking good
shifts for such groups is not a matter of correctness but definitely has
a big effect on aesthetics. For example, consider the following two
diffs. The first is what standard Git emits:
--- a/9c572b21dd090a1e5c5bb397053bf8043ffe7fb4:git-send-email.perl
+++ b/6dcfa306f2b67b733a7eb2d7ded1bc9987809edb:git-send-email.perl
@@ -231,6 +231,9 @@ if (!defined $initial_reply_to && $prompting) {
}
if (!$smtp_server) {
+ $smtp_server = $repo->config('sendemail.smtpserver');
+}
+if (!$smtp_server) {
foreach (qw( /usr/sbin/sendmail /usr/lib/sendmail )) {
if (-x $_) {
$smtp_server = $_;
The following diff is equivalent, but is obviously preferable from an
aesthetic point of view:
--- a/9c572b21dd090a1e5c5bb397053bf8043ffe7fb4:git-send-email.perl
+++ b/6dcfa306f2b67b733a7eb2d7ded1bc9987809edb:git-send-email.perl
@@ -230,6 +230,9 @@ if (!defined $initial_reply_to && $prompting) {
$initial_reply_to =~ s/(^\s+|\s+$)//g;
}
+if (!$smtp_server) {
+ $smtp_server = $repo->config('sendemail.smtpserver');
+}
if (!$smtp_server) {
foreach (qw( /usr/sbin/sendmail /usr/lib/sendmail )) {
if (-x $_) {
This patch teaches Git to pick better positions for such "diff sliders"
using heuristics that take the positions of nearby blank lines and the
indentation of nearby lines into account.
The existing Git code basically always shifts such "sliders" as far down
in the file as possible. The only exception is when the slider can be
aligned with a group of changed lines in the other file, in which case
Git favors depicting the change as one add+delete block rather than one
add and a slightly offset delete block. This naive algorithm often
yields ugly diffs.
Commit d634d61ed6 improved the situation somewhat by preferring to
position add/delete groups to make their last line a blank line, when
that is possible. This heuristic does more good than harm, but (1) it
can only help if there are blank lines in the right places, and (2)
always picks the last blank line, even if there are others that might be
better. The end result is that it makes perhaps 1/3 as many errors as
the default Git algorithm, but that still leaves a lot of ugly diffs.
This commit implements a new and much better heuristic for picking
optimal "slider" positions using the following approach: First observe
that each hypothetical positioning of a diff slider introduces two
splits: one between the context lines preceding the group and the first
added/deleted line, and the other between the last added/deleted line
and the first line of context following it. It tries to find the
positioning that creates the least bad splits.
Splits are evaluated based only on the presence and locations of nearby
blank lines, and the indentation of lines near the split. Basically, it
prefers to introduce splits adjacent to blank lines, between lines that
are indented less, and between lines with the same level of indentation.
In more detail:
1. It measures the following characteristics of a proposed splitting
position in a `struct split_measurement`:
* the number of blank lines above the proposed split
* whether the line directly after the split is blank
* the number of blank lines following that line
* the indentation of the nearest non-blank line above the split
* the indentation of the line directly below the split
* the indentation of the nearest non-blank line after that line
2. It combines the measured attributes using a bunch of
empirically-optimized weighting factors to derive a `struct
split_score` that measures the "badness" of splitting the text at
that position.
3. It combines the `split_score` for the top and the bottom of the
slider at each of its possible positions, and selects the position
that has the best `split_score`.
I determined the initial set of weighting factors by collecting a corpus
of Git histories from 29 open-source software projects in various
programming languages. I generated many diffs from this corpus, and
determined the best positioning "by eye" for about 6600 diff sliders. I
used about half of the repositories in the corpus (corresponding to
about 2/3 of the sliders) as a training set, and optimized the weights
against this corpus using a crude automated search of the parameter
space to get the best agreement with the manually-determined values.
Then I tested the resulting heuristic against the full corpus. The
results are summarized in the following table, in column `indent-1`:
| repository | count | Git 2.9.0 | compaction | compaction-fixed | indent-1 | indent-2 |
| --------------------- | ----- | -------------- | -------------- | ---------------- | -------------- | -------------- |
| afnetworking | 109 | 89 (81.7%) | 37 (33.9%) | 37 (33.9%) | 2 (1.8%) | 2 (1.8%) |
| alamofire | 30 | 18 (60.0%) | 14 (46.7%) | 15 (50.0%) | 0 (0.0%) | 0 (0.0%) |
| angular | 184 | 127 (69.0%) | 39 (21.2%) | 23 (12.5%) | 5 (2.7%) | 5 (2.7%) |
| animate | 313 | 2 (0.6%) | 2 (0.6%) | 2 (0.6%) | 2 (0.6%) | 2 (0.6%) |
| ant | 380 | 356 (93.7%) | 152 (40.0%) | 148 (38.9%) | 15 (3.9%) | 15 (3.9%) | *
| bugzilla | 306 | 263 (85.9%) | 109 (35.6%) | 99 (32.4%) | 14 (4.6%) | 15 (4.9%) | *
| corefx | 126 | 91 (72.2%) | 22 (17.5%) | 21 (16.7%) | 6 (4.8%) | 6 (4.8%) |
| couchdb | 78 | 44 (56.4%) | 26 (33.3%) | 28 (35.9%) | 6 (7.7%) | 6 (7.7%) | *
| cpython | 937 | 158 (16.9%) | 50 (5.3%) | 49 (5.2%) | 5 (0.5%) | 5 (0.5%) | *
| discourse | 160 | 95 (59.4%) | 42 (26.2%) | 36 (22.5%) | 18 (11.2%) | 13 (8.1%) |
| docker | 307 | 194 (63.2%) | 198 (64.5%) | 253 (82.4%) | 8 (2.6%) | 8 (2.6%) | *
| electron | 163 | 132 (81.0%) | 38 (23.3%) | 39 (23.9%) | 6 (3.7%) | 6 (3.7%) |
| git | 536 | 470 (87.7%) | 73 (13.6%) | 78 (14.6%) | 16 (3.0%) | 16 (3.0%) | *
| gitflow | 127 | 0 (0.0%) | 0 (0.0%) | 0 (0.0%) | 0 (0.0%) | 0 (0.0%) |
| ionic | 133 | 89 (66.9%) | 29 (21.8%) | 38 (28.6%) | 1 (0.8%) | 1 (0.8%) |
| ipython | 482 | 362 (75.1%) | 167 (34.6%) | 169 (35.1%) | 11 (2.3%) | 11 (2.3%) | *
| junit | 161 | 147 (91.3%) | 67 (41.6%) | 66 (41.0%) | 1 (0.6%) | 1 (0.6%) | *
| lighttable | 15 | 5 (33.3%) | 0 (0.0%) | 2 (13.3%) | 0 (0.0%) | 0 (0.0%) |
| magit | 88 | 75 (85.2%) | 11 (12.5%) | 9 (10.2%) | 1 (1.1%) | 0 (0.0%) |
| neural-style | 28 | 0 (0.0%) | 0 (0.0%) | 0 (0.0%) | 0 (0.0%) | 0 (0.0%) |
| nodejs | 781 | 649 (83.1%) | 118 (15.1%) | 111 (14.2%) | 4 (0.5%) | 5 (0.6%) | *
| phpmyadmin | 491 | 481 (98.0%) | 75 (15.3%) | 48 (9.8%) | 2 (0.4%) | 2 (0.4%) | *
| react-native | 168 | 130 (77.4%) | 79 (47.0%) | 81 (48.2%) | 0 (0.0%) | 0 (0.0%) |
| rust | 171 | 128 (74.9%) | 30 (17.5%) | 27 (15.8%) | 16 (9.4%) | 14 (8.2%) |
| spark | 186 | 149 (80.1%) | 52 (28.0%) | 52 (28.0%) | 2 (1.1%) | 2 (1.1%) |
| tensorflow | 115 | 66 (57.4%) | 48 (41.7%) | 48 (41.7%) | 5 (4.3%) | 5 (4.3%) |
| test-more | 19 | 15 (78.9%) | 2 (10.5%) | 2 (10.5%) | 1 (5.3%) | 1 (5.3%) | *
| test-unit | 51 | 34 (66.7%) | 14 (27.5%) | 8 (15.7%) | 2 (3.9%) | 2 (3.9%) | *
| xmonad | 23 | 22 (95.7%) | 2 (8.7%) | 2 (8.7%) | 1 (4.3%) | 1 (4.3%) | *
| --------------------- | ----- | -------------- | -------------- | ---------------- | -------------- | -------------- |
| totals | 6668 | 4391 (65.9%) | 1496 (22.4%) | 1491 (22.4%) | 150 (2.2%) | 144 (2.2%) |
| totals (training set) | 4552 | 3195 (70.2%) | 1053 (23.1%) | 1061 (23.3%) | 86 (1.9%) | 88 (1.9%) |
| totals (test set) | 2116 | 1196 (56.5%) | 443 (20.9%) | 430 (20.3%) | 64 (3.0%) | 56 (2.6%) |
In this table, the numbers are the count and percentage of human-rated
sliders that the corresponding algorithm got *wrong*. The columns are
* "repository" - the name of the repository used. I used the diffs
between successive non-merge commits on the HEAD branch of the
corresponding repository.
* "count" - the number of sliders that were human-rated. I chose most,
but not all, sliders to rate from those among which the various
algorithms gave different answers.
* "Git 2.9.0" - the default algorithm used by `git diff` in Git 2.9.0.
* "compaction" - the heuristic used by `git diff --compaction-heuristic`
in Git 2.9.0.
* "compaction-fixed" - the heuristic used by `git diff
--compaction-heuristic` after the fixes from earlier in this patch
series. Note that the results are not dramatically different than
those for "compaction". Both produce non-ideal diffs only about 1/3 as
often as the default `git diff`.
* "indent-1" - the new `--indent-heuristic` algorithm, using the first
set of weighting factors, determined as described above.
* "indent-2" - the new `--indent-heuristic` algorithm, using the final
set of weighting factors, determined as described below.
* `*` - indicates that repo was part of training set used to determine
the first set of weighting factors.
The fact that the heuristic performed nearly as well on the test set as
on the training set in column "indent-1" is a good indication that the
heuristic was not over-trained. Given that fact, I ran a second round of
optimization, using the entire corpus as the training set. The resulting
set of weights gave the results in column "indent-2". These are the
weights included in this patch.
The final result gives consistently and significantly better results
across the whole corpus than either `git diff` or `git diff
--compaction-heuristic`. It makes only about 1/30 as many errors as the
former and about 1/10 as many errors as the latter. (And a good fraction
of the remaining errors are for diffs that involve weirdly-formatted
code, sometimes apparently machine-generated.)
The tools that were used to do this optimization and analysis, along
with the human-generated data values, are recorded in a separate project
[1].
This patch adds a new command-line option `--indent-heuristic`, and a
new configuration setting `diff.indentHeuristic`, that activate this
heuristic. This interface is only meant for testing purposes, and should
be finalized before including this change in any release.
[1] https://github.com/mhagger/diff-slider-tools
Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
|
|
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>
|
Nguyễn Thái Ngọc Duy
Thomas Braun
Junio C Hamano
Eric Sunshine
Stefan Beller
Karthikeyan Singaravelan
Robert P. J. Day
Elijah Newren
Jeff King
Jonathan Tan
Carlos Martín Nieto
Anthony Sottile
Andreas Heiduk
Richard Hansen
Vegard Nossum
Michael Haggerty
Jacob Keller