1
0
Fork 0
mirror of https://github.com/git/git.git synced 2024-11-07 09:43:00 +01:00
Commit graph

9751 commits

Author SHA1 Message Date
Junio C Hamano
8a36cd87b7 Ninth batch for 2.11
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2016-10-10 14:09:12 -07:00
Junio C Hamano
1172e16af0 Merge branch 'jc/blame-reverse'
It is a common mistake to say "git blame --reverse OLD path",
expecting that the command line is dwimmed as if asking how lines
in path in an old revision OLD have survived up to the current
commit.

* jc/blame-reverse:
  blame: dwim "blame --reverse OLD" as "blame --reverse OLD.."
  blame: improve diagnosis for "--reverse NEW"
2016-10-10 14:03:51 -07:00
Junio C Hamano
a460ea4a3c Merge branch 'nd/shallow-deepen'
The existing "git fetch --depth=<n>" option was hard to use
correctly when making the history of an existing shallow clone
deeper.  A new option, "--deepen=<n>", has been added to make this
easier to use.  "git clone" also learned "--shallow-since=<date>"
and "--shallow-exclude=<tag>" options to make it easier to specify
"I am interested only in the recent N months worth of history" and
"Give me only the history since that version".

* nd/shallow-deepen: (27 commits)
  fetch, upload-pack: --deepen=N extends shallow boundary by N commits
  upload-pack: add get_reachable_list()
  upload-pack: split check_unreachable() in two, prep for get_reachable_list()
  t5500, t5539: tests for shallow depth excluding a ref
  clone: define shallow clone boundary with --shallow-exclude
  fetch: define shallow boundary with --shallow-exclude
  upload-pack: support define shallow boundary by excluding revisions
  refs: add expand_ref()
  t5500, t5539: tests for shallow depth since a specific date
  clone: define shallow clone boundary based on time with --shallow-since
  fetch: define shallow boundary with --shallow-since
  upload-pack: add deepen-since to cut shallow repos based on time
  shallow.c: implement a generic shallow boundary finder based on rev-list
  fetch-pack: use a separate flag for fetch in deepening mode
  fetch-pack.c: mark strings for translating
  fetch-pack: use a common function for verbose printing
  fetch-pack: use skip_prefix() instead of starts_with()
  upload-pack: move rev-list code out of check_non_tip()
  upload-pack: make check_non_tip() clean things up on error
  upload-pack: tighten number parsing at "deepen" lines
  ...
2016-10-10 14:03:50 -07:00
Junio C Hamano
a23ca1b8dc Eighth batch for 2.11
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2016-10-06 14:55:18 -07:00
Junio C Hamano
fbfe878f97 Merge branch 'ps/http-gssapi-cred-delegation'
In recent versions of cURL, GSSAPI credential delegation is
disabled by default due to CVE-2011-2192; introduce a configuration
to selectively allow enabling this.

* ps/http-gssapi-cred-delegation:
  http: control GSSAPI credential delegation
2016-10-06 14:53:11 -07:00
Junio C Hamano
8c98a68981 Merge branch 'vn/revision-shorthand-for-side-branch-log'
"git log rev^..rev" is an often-used revision range specification
to show what was done on a side branch merged at rev.  This has
gained a short-hand "rev^-1".  In general "rev^-$n" is the same as
"^rev^$n rev", i.e. what has happened on other branches while the
history leading to nth parent was looking the other way.

* vn/revision-shorthand-for-side-branch-log:
  revision: new rev^-n shorthand for rev^n..rev
2016-10-06 14:53:10 -07:00
Junio C Hamano
66c22ba6fb Merge branch 'jk/ambiguous-short-object-names'
When given an abbreviated object name that is not (or more
realistically, "no longer") unique, we gave a fatal error
"ambiguous argument".  This error is now accompanied by hints that
lists the objects that begins with the given prefix.  During the
course of development of this new feature, numerous minor bugs were
uncovered and corrected, the most notable one of which is that we
gave "short SHA1 xxxx is ambiguous." twice without good reason.

* jk/ambiguous-short-object-names:
  get_short_sha1: make default disambiguation configurable
  get_short_sha1: list ambiguous objects on error
  for_each_abbrev: drop duplicate objects
  sha1_array: let callbacks interrupt iteration
  get_short_sha1: mark ambiguity error for translation
  get_short_sha1: NUL-terminate hex prefix
  get_short_sha1: refactor init of disambiguation code
  get_short_sha1: parse tags when looking for treeish
  get_sha1: propagate flags to child functions
  get_sha1: avoid repeating ourselves via ONLY_TO_DIE
  get_sha1: detect buggy calls with multiple disambiguators
2016-10-06 14:53:10 -07:00
Junio C Hamano
0cf36115dc Sync with 2.10.1
* maint:
  Git 2.10.1
2016-10-03 13:32:41 -07:00
Junio C Hamano
30d687dfd5 Seventh batch for 2.11
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2016-10-03 13:32:19 -07:00
Junio C Hamano
8f0e543950 Merge branch 'pb/rev-list-reverse-with-count'
Doc update to clarify what "log -3 --reverse" does.

* pb/rev-list-reverse-with-count:
  rev-list-options: clarify the usage of --reverse
2016-10-03 13:30:39 -07:00
Junio C Hamano
347408496a Merge branch 'ik/gitweb-force-highlight'
"gitweb" can spawn "highlight" to show blob contents with
(programming) language-specific syntax highlighting, but only
when the language is known.  "highlight" can however be told
to make the guess itself by giving it "--force" option, which
has been enabled.

* ik/gitweb-force-highlight:
  gitweb: use highlight's shebang detection
  gitweb: remove unused guess_file_syntax() parameter
2016-10-03 13:30:34 -07:00
Junio C Hamano
6406bdc0b9 Git 2.10.1
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2016-10-03 13:24:18 -07:00
Junio C Hamano
3d0049ea35 Merge branch 'jk/doc-cvs-update' into maint
Documentation around tools to import from CVS was fairly outdated.

* jk/doc-cvs-update:
  docs/cvs-migration: mention cvsimport caveats
  docs/cvs-migration: update link to cvsps homepage
  docs/cvsimport: prefer cvs-fast-export to parsecvs
2016-10-03 13:22:25 -07:00
Petr Stodulka
26a7b23429 http: control GSSAPI credential delegation
Delegation of credentials is disabled by default in libcurl since
version 7.21.7 due to security vulnerability CVE-2011-2192. Which
makes troubles with GSS/kerberos authentication when delegation
of credentials is required. This can be changed with option
CURLOPT_GSSAPI_DELEGATION in libcurl with set expected parameter
since libcurl version 7.22.0.

This patch provides new configuration variable http.delegation
which corresponds to curl parameter "--delegation" (see man 1 curl).

The following values are supported:

* none (default).
* policy
* always

Signed-off-by: Petr Stodulka <pstodulk@redhat.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2016-09-29 20:39:23 -07:00
Junio C Hamano
3ef7618e61 Sync with maint
* maint:
  Prepare for 2.10.1
2016-09-29 16:58:29 -07:00
Junio C Hamano
641b158a28 Sixth batch for 2.11
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2016-09-29 16:58:20 -07:00
Junio C Hamano
92d426662b Prepare for 2.10.1
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2016-09-29 16:52:15 -07:00
Junio C Hamano
bf3a55a21b Merge branch 'et/add-chmod-x' into maint
"git add --chmod=+x" added recently lacked documentation, which has
been corrected.

* et/add-chmod-x:
  add: document the chmod option
2016-09-29 16:49:46 -07:00
Junio C Hamano
d336b67568 Merge branch 'nd/checkout-disambiguation' into maint
"git checkout <word>" does not follow the usual disambiguation
rules when the <word> can be both a rev and a path, to allow
checking out a branch 'foo' in a project that happens to have a
file 'foo' in the working tree without having to disambiguate.
This was poorly documented and the check was incorrect when the
command was run from a subdirectory.

* nd/checkout-disambiguation:
  checkout: fix ambiguity check in subdir
  checkout.txt: document a common case that ignores ambiguation rules
  checkout: add some spaces between code and comment
2016-09-29 16:49:44 -07:00
Junio C Hamano
7106584137 Merge branch 'ep/doc-check-ref-format-example' into maint
A shell script example in check-ref-format documentation has been
fixed.

* ep/doc-check-ref-format-example:
  git-check-ref-format.txt: fixup documentation
2016-09-29 16:49:43 -07:00
Junio C Hamano
a74a3b7a0b Merge branch 'mm/config-color-ui-default-to-auto' into maint
Documentation for individual configuration variables to control use
of color (like `color.grep`) said that their default value is
'false', instead of saying their default is taken from `color.ui`.
When we updated the default value for color.ui from 'false' to
'auto' quite a while ago, all of them broke.  This has been
corrected.

* mm/config-color-ui-default-to-auto:
  Documentation/config: default for color.* is color.ui
2016-09-29 16:49:42 -07:00
Junio C Hamano
eb293ac8d6 Merge branch 'jk/reduce-gc-aggressive-depth' into maint
"git gc --aggressive" used to limit the delta-chain length to 250,
which is way too deep for gaining additional space savings and is
detrimental for runtime performance.  The limit has been reduced to
50.

* jk/reduce-gc-aggressive-depth:
  gc: default aggressive depth to 50
2016-09-29 16:49:42 -07:00
Pranit Bauva
04be69478f rev-list-options: clarify the usage of --reverse
Users often wonder if the oldest or the newest n commits are shown
by `log -n --reverse`.  Clarify that --reverse kicks in only after
deciding which commits are to be shown to unconfuse them.

Reported-by: Ruediger Meier <sweet_f_a@gmx.de>
Signed-off-by: Pranit Bauva <pranit.bauva@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2016-09-27 15:09:07 -07:00
Vegard Nossum
8779351dd7 revision: new rev^-n shorthand for rev^n..rev
"git log rev^..rev" is commonly used to show all work done on and merged
from a side branch. This patch introduces a shorthand "rev^-" for this
and additionally allows "rev^-$n" to mean "reachable from rev, excluding
what is reachable from the nth parent of rev". For example, for a
two-parent merge, you can use rev^-2 to get the set of commits which were
made to the main branch while the topic branch was prepared.

Signed-off-by: Vegard Nossum <vegard.nossum@oracle.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2016-09-27 10:59:28 -07:00
Junio C Hamano
21f862b498 Fifth batch for 2.11
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2016-09-26 16:11:46 -07:00
Junio C Hamano
bd250ab5ce Merge branch 'jk/doc-cvs-update'
Documentation around tools to import from CVS was fairly outdated.

* jk/doc-cvs-update:
  docs/cvs-migration: mention cvsimport caveats
  docs/cvs-migration: update link to cvsps homepage
  docs/cvsimport: prefer cvs-fast-export to parsecvs
2016-09-26 16:09:22 -07:00
Junio C Hamano
31b83f361b Merge branch 'nd/checkout-disambiguation'
"git checkout <word>" does not follow the usual disambiguation
rules when the <word> can be both a rev and a path, to allow
checking out a branch 'foo' in a project that happens to have a
file 'foo' in the working tree without having to disambiguate.
This was poorly documented and the check was incorrect when the
command was run from a subdirectory.

* nd/checkout-disambiguation:
  checkout: fix ambiguity check in subdir
  checkout.txt: document a common case that ignores ambiguation rules
  checkout: add some spaces between code and comment
2016-09-26 16:09:18 -07:00
Junio C Hamano
e447d3182c Merge branch 'jt/format-patch-rfc'
In some projects, it is common to use "[RFC PATCH]" as the subject
prefix for a patch meant for discussion rather than application.  A
new option "--rfc" was a short-hand for "--subject-prefix=RFC PATCH"
to help the participants of such projects.

* jt/format-patch-rfc:
  format-patch: add "--rfc" for the common case of [RFC PATCH]
2016-09-26 16:09:17 -07:00
Junio C Hamano
2a1f3fe6e3 Merge branch 'ep/doc-check-ref-format-example'
A shell script example in check-ref-format documentation has been
fixed.

* ep/doc-check-ref-format-example:
  git-check-ref-format.txt: fixup documentation
2016-09-26 16:09:17 -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
Junio C Hamano
7fcc056dfa Merge branch 'mm/config-color-ui-default-to-auto'
Documentation for individual configuration variables to control use
of color (like `color.grep`) said that their default value is
'false', instead of saying their default is taken from `color.ui`.
When we updated the default value for color.ui from 'false' to
'auto' quite a while ago, all of them broke.  This has been
corrected.

* mm/config-color-ui-default-to-auto:
  Documentation/config: default for color.* is color.ui
2016-09-26 16:09:15 -07:00
Jeff King
16ddcd403b sha1_array: let callbacks interrupt iteration
The callbacks for iterating a sha1_array must have a void
return.  This is unlike our usual for_each semantics, where
a callback may interrupt iteration and have its value
propagated. Let's switch it to the usual form, which will
enable its use in more places (e.g., where we are replacing
an existing iteration with a different data structure).

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2016-09-26 11:46:41 -07:00
Ian Kelling
779a206632 gitweb: use highlight's shebang detection
The "highlight" binary can, in some cases, determine the language type
by the means of file contents, for example the shebang in the first line
for some scripting languages.  Make use of this autodetection for files
which syntax is not known by gitweb.  In that case, pass the blob
contents to "highlight --force"; the parameter is needed to make it
always generate HTML output (which includes HTML-escaping).

Although we now run highlight on files which do not end up highlighted,
performance is virtually unaffected because when we call highlight, it
is used for escaping HTML.  In the case that highlight is used, gitweb
calls sanitize() instead of esc_html(), and the latter is significantly
slower (it does more, being roughly a superset of sanitize()).  Simple
benchmark comparing performance of 'blob' view of files without syntax
highlighting in gitweb before and after this change indicates ±1%
difference in request time for all file types.  Benchmark was performed
on local instance on Debian, using Apache/2.4.23 web server and CGI.

Document the feature and improve syntax highlight documentation, add
test to ensure gitweb doesn't crash when language detection is used.

Signed-off-by: Ian Kelling <ian@iankelling.org>
Acked-by: Jakub Narębski <jnareb@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2016-09-25 16:39:11 -07:00
Jeff King
106b672ade docs/cvs-migration: mention cvsimport caveats
Back when this guide was written, cvsimport was the only
game in town. These days it is probably not the best option.
Rather than go into details, let's point people to the note
at the top of cvsimport which gives other options.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2016-09-22 11:23:45 -07:00
Jeff King
72e0877a1d docs/cvs-migration: update link to cvsps homepage
The old page gives a 404 now. Searching for "cvsps" via
Google returns a GitHub project page as the top hit.

Reported-by: Dan Pritts
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2016-09-22 11:23:45 -07:00
Jeff King
1eba3e5147 docs/cvsimport: prefer cvs-fast-export to parsecvs
parsecvs maintenance was taken over by ESR, and the name
changed to cvs-fast-export as it learned to support that
output format. Let's point to cvs-fast-export, as it should
have additional bug-fixes and be more convenient to use.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2016-09-22 11:23:45 -07:00
Junio C Hamano
6fe1b1407e Fourth batch for 2.11
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2016-09-21 15:20:44 -07:00
Junio C Hamano
0952ca8a95 Merge branch 'jk/reduce-gc-aggressive-depth'
"git gc --aggressive" used to limit the delta-chain length to 250,
which is way too deep for gaining additional space savings and is
detrimental for runtime performance.  The limit has been reduced to
50.

* jk/reduce-gc-aggressive-depth:
  gc: default aggressive depth to 50
2016-09-21 15:15:30 -07:00
Junio C Hamano
a9817aaef8 Merge branch 'et/add-chmod-x'
"git add --chmod=+x" added recently lacked documentation, which has
been corrected.

* et/add-chmod-x:
  add: document the chmod option
2016-09-21 15:15:19 -07:00
Junio C Hamano
7889ed25ac Merge branch 'js/cat-file-filters'
Even though "git hash-objects", which is a tool to take an
on-filesystem data stream and put it into the Git object store,
allowed to perform the "outside-world-to-Git" conversions (e.g.
end-of-line conversions and application of the clean-filter), and
it had the feature on by default from very early days, its reverse
operation "git cat-file", which takes an object from the Git object
store and externalize for the consumption by the outside world,
lacked an equivalent mechanism to run the "Git-to-outside-world"
conversion.  The command learned the "--filters" option to do so.

* js/cat-file-filters:
  cat-file: support --textconv/--filters in batch mode
  cat-file --textconv/--filters: allow specifying the path separately
  cat-file: introduce the --filters option
  cat-file: fix a grammo in the man page
2016-09-21 15:15:19 -07:00
Elia Pinto
92dece7024 git-check-ref-format.txt: fixup documentation
die is not a standard shell function. Use
a different shell code for the example.

Signed-off-by: Elia Pinto <gitter.spiros@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2016-09-21 11:12:41 -07:00
Josh Triplett
68e83a5b82 format-patch: add "--rfc" for the common case of [RFC PATCH]
Add an alias for --subject-prefix='RFC PATCH', which is used
commonly in some development communities to deserve such a
short-hand.

Signed-off-by: Josh Triplett <josh@joshtriplett.org>
Reviewed-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2016-09-21 08:58:10 -07:00
Nguyễn Thái Ngọc Duy
19e5656345 checkout.txt: document a common case that ignores ambiguation rules
Normally we err on the safe side: if something can be seen as both an
SHA1 and a pathspec, we stop and scream. In checkout, there is one
exception added in 859fdab (git-checkout: improve error messages, detect
ambiguities. - 2008-07-23), to allow the common case "git checkout
branch". Let's document this exception.

Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2016-09-21 08:44:41 -07:00
Junio C Hamano
f6727b0509 Sync with maint
* maint:
  Start preparing for 2.10.1
2016-09-19 13:55:18 -07:00
Junio C Hamano
7c0304af62 Start preparing for 2.10.1
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2016-09-19 13:54:50 -07:00
Junio C Hamano
f0b2db228b Merge branch 'po/range-doc' into maint
Clarify various ways to specify the "revision ranges" in the
documentation.

* po/range-doc:
  doc: revisions: sort examples and fix alignment of the unchanged
  doc: revisions: show revision expansion in examples
  doc: revisions - clarify reachability examples
  doc: revisions - define `reachable`
  doc: gitrevisions - clarify 'latter case' is revision walk
  doc: gitrevisions - use 'reachable' in page description
  doc: revisions: single vs multi-parent notation comparison
  doc: revisions: extra clarification of <rev>^! notation effects
  doc: revisions: give headings for the two and three dot notations
  doc: show the actual left, right, and boundary marks
  doc: revisions - name the left and right sides
  doc: use 'symmetric difference' consistently
2016-09-19 13:51:38 -07:00
Junio C Hamano
2118cdc7d3 Third batch for 2.11
This round they are somewhat bigger topics.

Signed-off-by: Junio C Hamano <gitster@pobox.com>
2016-09-19 13:48:25 -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
Michael Haggerty
433860f3d0 diff: improve positioning of add/delete blocks in diffs
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>
2016-09-19 10:25:11 -07:00
Matthieu Moy
14d16e2b35 Documentation/config: default for color.* is color.ui
Since 4c7f181 (make color.ui default to 'auto', 2013-06-10), the
default for color.* when nothing is set is 'auto' and we still claimed
that the default was 'false'. Be more precise by saying explicitly
that the default is to follow color.ui, and recall that the default is
'auto' to avoid one indirection for the reader.

Signed-off-by: Matthieu Moy <Matthieu.Moy@imag.fr>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2016-09-16 12:34:14 -07:00