# git-shortlog

## NAME



           git-shortlog - Summarize 'git log' output
    


## SYNOPSIS



           _git shortlog_ [<options>] [<revision-range>] [[--] <path>...]
           git log --pretty=short | _git shortlog_ [<options>]
    


## DESCRIPTION



           Summarizes _git log_ output in a format suitable for inclusion in
           release announcements. Each commit will be grouped by author and
           title.
    
           Additionally, "[PATCH]" will be stripped from the commit
           description.
    
           If no revisions are passed on the command line and either standard
           input is not a terminal or there is no current branch, _git_
           _shortlog_ will output a summary of the log read from standard
           input, without reference to the current repository.
    


## OPTIONS



           -n, --numbered
               Sort output according to the number of commits per author
               instead of author alphabetic order.
    
           -s, --summary
               Suppress commit description and provide a commit count summary
               only.
    
           -e, --email
               Show the email address of each author.
    
           --format[=<format>]
               Instead of the commit subject, use some other information to
               describe each commit.  _< format>_ can be any string accepted by
               the **--format** option of _git log_ , such as _* [%h] %s_. (See the
               "PRETTY FORMATS" section of git-log(1).)
    
                   Each pretty-printed commit will be rewrapped before it is shown.
    
           --date=<format>
               Show dates formatted according to the given date string. (See
               the **--date** option in the "Commit Formatting" section of
               git-log(1)). Useful with **--group=format:**_< format>_.
    
           --group=<type>
               Group commits based on _< type>_. If no **--group** option is
               specified, the default is **author**.  _< type>_ is one of:
    
               •   **author** , commits are grouped by author
    
               •   **committer** , commits are grouped by committer (the same as
                   **-c**)
    
               •   **trailer:**_< field>_, the _< field>_ is interpreted as a
                   case-insensitive commit message trailer (see
                   git-interpret-trailers(1)). For example, if your project
                   uses **Reviewed-by** trailers, you might want to see who has
                   been reviewing with **git shortlog -ns**
                   **--group=trailer:reviewed-by**.
    
               •   **format:**_< format>_, any string accepted by the **--format**
                   option of _git log_. (See the "PRETTY FORMATS" section of
                   git-log(1).)
    
                   Note that commits that do not include the trailer will not
                   be counted. Likewise, commits with multiple trailers
                   (e.g., multiple signoffs) may be counted more than once
                   (but only once per unique trailer value in that commit).
    
                   Shortlog will attempt to parse each trailer value as a
                   **name** _< email>_ identity. If successful, the mailmap is
                   applied and the email is omitted unless the **--email** option
                   is specified. If the value cannot be parsed as an
                   identity, it will be taken literally and completely.
    
               If **--group** is specified multiple times, commits are counted
               under each value (but again, only once per unique value in
               that commit). For example, **git shortlog --group=author**
               **--group=trailer:co-authored-by** counts both authors and
               co-authors.
    
           -c, --committer
               This is an alias for **--group=committer**.
    
           -w[<width>[,<indent1>[,<indent2>]]]
               Linewrap the output by wrapping each line at **width**. The first
               line of each entry is indented by **indent1** spaces, and the
               second and subsequent lines are indented by **indent2** spaces.
               **width** , **indent1** , and **indent2** default to 76, 6 and 9
               respectively.
    
               If width is **0**(zero) then indent the lines of the output
               without wrapping them.
    
           <revision-range>
               Show only commits in the specified revision range. When no
               <revision-range> is specified, it defaults to **HEAD**(i.e. the
               whole history leading to the current commit).  **origin..HEAD**
               specifies all the commits reachable from the current commit
               (i.e.  **HEAD**), but not from **origin**. For a complete list of ways
               to spell <revision-range>, see the "Specifying Ranges" section
               of gitrevisions(7).
    
           [--] <path>...
               Consider only commits that are enough to explain how the files
               that match the specified paths came to be.
    
               Paths may need to be prefixed with **--** to separate them from
               options or the revision range, when confusion arises.
    
       **Commit Limiting**
           Besides specifying a range of commits that should be listed using
           the special notations explained in the description, additional
           commit limiting may be applied.
    
           Using more options generally further limits the output (e.g.
           **--since=**_< date1>_ limits to commits newer than _< date1>_, and using it
           with **--grep=**_< pattern>_ further limits to commits whose log message
           has a line that matches _< pattern>_), unless otherwise noted.
    
           Note that these are applied before commit ordering and formatting
           options, such as **--reverse**.
    
           **-**_< number>_, **-n** _< number>_, **--max-count=**_< number>_
               Limit the output to _< number>_ commits.
    
           **--skip=**_< number>_
               Skip _< number>_ commits before starting to show the commit
               output.
    
           **--since=**_< date>_, **--after=**_< date>_
               Show commits more recent than _< date>_.
    
           **--since-as-filter=**_< date>_
               Show all commits more recent than _< date>_. This visits all
               commits in the range, rather than stopping at the first commit
               which is older than _< date>_.
    
           **--until=**_< date>_, **--before=**_< date>_
               Show commits older than _< date>_.
    
           **--author=**_< pattern>_, **--committer=**_< pattern>_
               Limit the commits output to ones with author/committer header
               lines that match the _< pattern>_ regular expression. With more
               than one **--author=**_< pattern>_, commits whose author matches any
               of the _< pattern>_ are chosen (similarly for multiple
               **--committer=**_< pattern>_).
    
           **--grep-reflog=**_< pattern>_
               Limit the commits output to ones with reflog entries that
               match the _< pattern>_ regular expression. With more than one
               **--grep-reflog** , commits whose reflog message matches any of the
               given patterns are chosen. It is an error to use this option
               unless **--walk-reflogs** is in use.
    
           **--grep=**_< pattern>_
               Limit the commits output to ones with a log message that
               matches the _< pattern>_ regular expression. With more than one
               **--grep=**_< pattern>_, commits whose message matches any of the
               _< pattern>_ are chosen (but see **--all-match**).
    
               When **--notes** is in effect, the message from the notes is
               matched as if it were part of the log message.
    
           **--all-match**
               Limit the commits output to ones that match all given **--grep** ,
               instead of ones that match at least one.
    
           **--invert-grep**
               Limit the commits output to ones with a log message that do
               not match the _< pattern>_ specified with **--grep=**_< pattern>_.
    
           **-i** , **--regexp-ignore-case**
               Match the regular expression limiting patterns without regard
               to letter case.
    
           **--basic-regexp**
               Consider the limiting patterns to be basic regular
               expressions; this is the default.
    
           **-E** , **--extended-regexp**
               Consider the limiting patterns to be extended regular
               expressions instead of the default basic regular expressions.
    
           **-F** , **--fixed-strings**
               Consider the limiting patterns to be fixed strings (don’t
               interpret pattern as a regular expression).
    
           **-P** , **--perl-regexp**
               Consider the limiting patterns to be Perl-compatible regular
               expressions.
    
               Support for these types of regular expressions is an optional
               compile-time dependency. If Git wasn’t compiled with support
               for them providing this option will cause it to die.
    
           **--remove-empty**
               Stop when a given path disappears from the tree.
    
           **--merges**
               Print only merge commits. This is exactly the same as
               **--min-parents=2**.
    
           **--no-merges**
               Do not print commits with more than one parent. This is
               exactly the same as **--max-parents=1**.
    
           **--min-parents=**_< number>_, **--max-parents=**_< number>_, **--no-min-parents** ,
           **--no-max-parents**
               Show only commits which have at least (or at most) that many
               parent commits. In particular, **--max-parents=1** is the same as
               **--no-merges** , **--min-parents=2** is the same as **--merges**.
               **--max-parents=0** gives all root commits and **--min-parents=3** all
               octopus merges.
    
               **--no-min-parents** and **--no-max-parents** reset these limits (to
               no limit) again. Equivalent forms are **--min-parents=0**(any
               commit has 0 or more parents) and **--max-parents=-1**(negative
               numbers denote no upper limit).
    
           **--first-parent**
               When finding commits to include, follow only the first parent
               commit upon seeing a merge commit. This option can give a
               better overview when viewing the evolution of a particular
               topic branch, because merges into a topic branch tend to be
               only about adjusting to updated upstream from time to time,
               and this option allows you to ignore the individual commits
               brought in to your history by such a merge.
    
           **--exclude-first-parent-only**
               When finding commits to exclude (with a _^_), follow only the
               first parent commit upon seeing a merge commit. This can be
               used to find the set of changes in a topic branch from the
               point where it diverged from the remote branch, given that
               arbitrary merges can be valid topic branch changes.
    
           **--not**
               Reverses the meaning of the _^_ prefix (or lack thereof) for all
               following revision specifiers, up to the next **--not**. When used
               on the command line before --stdin, the revisions passed
               through stdin will not be affected by it. Conversely, when
               passed via standard input, the revisions passed on the command
               line will not be affected by it.
    
           **--all**
               Pretend as if all the refs in **refs/** , along with **HEAD** , are
               listed on the command line as _< commit>_.
    
           **--branches**[**=**_< pattern>_]
               Pretend as if all the refs in **refs/heads** are listed on the
               command line as _< commit>_. If _< pattern>_ is given, limit
               branches to ones matching given shell glob. If _< pattern>_ lacks
               _?_ , _*_ , or _[_ , _/*_ at the end is implied.
    
           **--tags**[**=**_< pattern>_]
               Pretend as if all the refs in **refs/tags** are listed on the
               command line as _< commit>_. If _< pattern>_ is given, limit tags to
               ones matching given shell glob. If pattern lacks _?_ , _*_ , or _[_ ,
               _/*_ at the end is implied.
    
           **--remotes**[**=**_< pattern>_]
               Pretend as if all the refs in **refs/remotes** are listed on the
               command line as _< commit>_. If _< pattern>_ is given, limit
               remote-tracking branches to ones matching given shell glob. If
               pattern lacks _?_ , _*_ , or _[_ , _/*_ at the end is implied.
    
           **--glob=**_< glob-pattern>_
               Pretend as if all the refs matching shell glob _< glob-pattern>_
               are listed on the command line as _< commit>_. Leading _refs/_ , is
               automatically prepended if missing. If pattern lacks _?_ , _*_ , or
               _[_ , _/*_ at the end is implied.
    
           **--exclude=**_< glob-pattern>_
               Do not include refs matching _< glob-pattern>_ that the next
               **--all** , **--branches** , **--tags** , **--remotes** , or **--glob** would
               otherwise consider. Repetitions of this option accumulate
               exclusion patterns up to the next **--all** , **--branches** , **--tags** ,
               **--remotes** , or **--glob** option (other options or arguments do not
               clear accumulated patterns).
    
               The patterns given should not begin with **refs/heads** ,
               **refs/tags** , or **refs/remotes** when applied to **--branches** , **--tags** ,
               or **--remotes** , respectively, and they must begin with **refs/**
               when applied to **--glob** or **--all**. If a trailing _/*_ is intended,
               it must be given explicitly.
    
           **--exclude-hidden=**(**fetch** |**receive** |**uploadpack**)
               Do not include refs that would be hidden by **git-fetch** ,
               **git-receive-pack** or **git-upload-pack** by consulting the
               appropriate **fetch.hideRefs** , **receive.hideRefs** or
               **uploadpack.hideRefs** configuration along with **transfer.hideRefs**
               (see git-config(1)). This option affects the next pseudo-ref
               option **--all** or **--glob** and is cleared after processing them.
    
           **--reflog**
               Pretend as if all objects mentioned by reflogs are listed on
               the command line as _< commit>_.
    
           **--alternate-refs**
               Pretend as if all objects mentioned as ref tips of alternate
               repositories were listed on the command line. An alternate
               repository is any repository whose object directory is
               specified in **objects/info/alternates**. The set of included
               objects may be modified by **core.alternateRefsCommand** , etc. See
               git-config(1).
    
           **--single-worktree**
               By default, all working trees will be examined by the
               following options when there are more than one (see
               git-worktree(1)): **--all** , **--reflog** and **--indexed-objects**. This
               option forces them to examine the current working tree only.
    
           **--ignore-missing**
               Upon seeing an invalid object name in the input, pretend as if
               the bad input was not given.
    
           **--bisect**
               Pretend as if the bad bisection ref **refs/bisect/bad** was listed
               and as if it was followed by **--not** and the good bisection refs
               **refs/bisect/good-*** on the command line.
    
           **--stdin**
               In addition to getting arguments from the command line, read
               them from standard input as well. This accepts commits and
               pseudo-options like **--all** and **--glob=**. When a **--** separator is
               seen, the following input is treated as paths and used to
               limit the result. Flags like **--not** which are read via standard
               input are only respected for arguments passed in the same way
               and will not influence any subsequent command line arguments.
    
           **--cherry-mark**
               Like **--cherry-pick**(see below) but mark equivalent commits
               with **=** rather than omitting them, and inequivalent ones with
               **+**.
    
           **--cherry-pick**
               Omit any commit that introduces the same change as another
               commit on the “other side” when the set of commits are limited
               with symmetric difference.
    
               For example, if you have two branches, **A** and **B** , a usual way to
               list all commits on only one side of them is with **--left-right**
               (see the example below in the description of the **--left-right**
               option). However, it shows the commits that were cherry-picked
               from the other branch (for example, “3rd on b” may be
               cherry-picked from branch A). With this option, such pairs of
               commits are excluded from the output.
    
           **--left-only** , **--right-only**
               List only commits on the respective side of a symmetric
               difference, i.e. only those which would be marked < resp. > by
               **--left-right**.
    
               For example, **--cherry-pick --right-only A...B** omits those
               commits from **B** which are in **A** or are patch-equivalent to a
               commit in **A**. In other words, this lists the **+** commits from **git**
               **cherry A B**. More precisely, **--cherry-pick --right-only**
               **--no-merges** gives the exact list.
    
           **--cherry**
               A synonym for **--right-only --cherry-mark --no-merges** ; useful
               to limit the output to the commits on our side and mark those
               that have been applied to the other side of a forked history
               with **git log --cherry upstream...mybranch** , similar to **git**
               **cherry upstream mybranch**.
    
           **-g** , **--walk-reflogs**
               Instead of walking the commit ancestry chain, walk reflog
               entries from the most recent one to older ones. When this
               option is used you cannot specify commits to exclude (that is,
               **^**_< commit>_, _< commit1>_**..**_< commit2>_, and _< commit1>_**...**_< commit2>_
               notations cannot be used).
    
               With **--pretty** format other than **oneline** and **reference**(for
               obvious reasons), this causes the output to have two extra
               lines of information taken from the reflog. The reflog
               designator in the output may be shown as **ref@**{_< Nth>_} (where
               _< Nth>_ is the reverse-chronological index in the reflog) or as
               **ref@**{_< timestamp>_} (with the _< timestamp>_ for that entry),
               depending on a few rules:
    
                1. If the starting point is specified as **ref@**{_< Nth>_}, show
                   the index format.
    
                2. If the starting point was specified as **ref@**{now}, show the
                   timestamp format.
    
                3. If neither was used, but **--date** was given on the command
                   line, show the timestamp in the format requested by
                   **--date**.
    
                4. Otherwise, show the index format.
    
               Under **--pretty=oneline** , the commit message is prefixed with
               this information on the same line. This option cannot be
               combined with **--reverse**. See also git-reflog(1).
    
               Under **--pretty=reference** , this information will not be shown
               at all.
    
           **--merge**
               Show commits touching conflicted paths in the range
               **HEAD...**_< other>_, where _< other>_ is the first existing pseudoref
               in **MERGE_HEAD** , **CHERRY_PICK_HEAD** , **REVERT_HEAD** or **REBASE_HEAD**.
               Only works when the index has unmerged entries. This option
               can be used to show relevant commits when resolving conflicts
               from a 3-way merge.
    
           **--boundary**
               Output excluded boundary commits. Boundary commits are
               prefixed with **-**.
    
       **History Simplification**
           Sometimes you are only interested in parts of the history, for
           example the commits modifying a particular <path>. But there are
           two parts of _History Simplification_ , one part is selecting the
           commits and the other is how to do it, as there are various
           strategies to simplify the history.
    
           The following options select the commits to be shown:
    
           _< paths>_
               Commits modifying the given <paths> are selected.
    
           **--simplify-by-decoration**
               Commits that are referred by some branch or tag are selected.
    
           Note that extra commits can be shown to give a meaningful history.
    
           The following options affect the way the simplification is
           performed:
    
           **Default mode**
               Simplifies the history to the simplest history explaining the
               final state of the tree. Simplest because it prunes some side
               branches if the end result is the same (i.e. merging branches
               with the same content)
    
           **--show-pulls**
               Include all commits from the default mode, but also any merge
               commits that are not TREESAME to the first parent but are
               TREESAME to a later parent. This mode is helpful for showing
               the merge commits that "first introduced" a change to a
               branch.
    
           **--full-history**
               Same as the default mode, but does not prune some history.
    
           **--dense**
               Only the selected commits are shown, plus some to have a
               meaningful history.
    
           **--sparse**
               All commits in the simplified history are shown.
    
           **--simplify-merges**
               Additional option to **--full-history** to remove some needless
               merges from the resulting history, as there are no selected
               commits contributing to this merge.
    
           **--ancestry-path**[**=**_< commit>_]
               When given a range of commits to display (e.g.
               _< commit1>_**..**_< commit2>_ or _< commit2>_ **^**_< commit1>_), and a commit
               _< commit>_ in that range, only display commits in that range
               that are ancestors of _< commit>_, descendants of _< commit>_, or
               _< commit>_ itself. If no commit is specified, use _< commit1>_ (the
               excluded part of the range) as _< commit>_. Can be passed
               multiple times; if so, a commit is included if it is any of
               the commits given or if it is an ancestor or descendant of one
               of them.
    
           A more detailed explanation follows.
    
           Suppose you specified **foo** as the _< paths>_. We shall call commits
           that modify **foo**!TREESAME, and the rest TREESAME. (In a diff
           filtered for **foo** , they look different and equal, respectively.)
    
           In the following, we will always refer to the same example history
           to illustrate the differences between simplification settings. We
           assume that you are filtering for a file **foo** in this commit graph:
    
                         .-A---M---N---O---P---Q
                        /     /   /   /   /   /
                       I     B   C   D   E   Y
                        \   /   /   /   /   /
                         `-------------'   X
    
           The horizontal line of history A---Q is taken to be the first
           parent of each merge. The commits are:
    
           •   **I** is the initial commit, in which **foo** exists with contents
               **asdf** , and a file **quux** exists with contents **quux**. Initial
               commits are compared to an empty tree, so **I** is !TREESAME.
    
           •   In **A** , **foo** contains just **foo**.
    
           •   **B** contains the same change as **A**. Its merge **M** is trivial and
               hence TREESAME to all parents.
    
           •   **C** does not change **foo** , but its merge **N** changes it to **foobar** ,
               so it is not TREESAME to any parent.
    
           •   **D** sets **foo** to **baz**. Its merge **O** combines the strings from **N** and
               **D** to **foobarbaz** ; i.e., it is not TREESAME to any parent.
    
           •   **E** changes **quux** to **xyzzy** , and its merge **P** combines the strings
               to **quux xyzzy**.  **P** is TREESAME to **O** , but not to **E**.
    
           •   **X** is an independent root commit that added a new file **side** ,
               and **Y** modified it.  **Y** is TREESAME to **X**. Its merge **Q** added **side**
               to **P** , and **Q** is TREESAME to **P** , but not to **Y**.
    
           **rev-list** walks backwards through history, including or excluding
           commits based on whether **--full-history** and/or parent rewriting
           (via **--parents** or **--children**) are used. The following settings are
           available.
    
           Default mode
               Commits are included if they are not TREESAME to any parent
               (though this can be changed, see **--sparse** below). If the
               commit was a merge, and it was TREESAME to one parent, follow
               only that parent. (Even if there are several TREESAME parents,
               follow only one of them.) Otherwise, follow all parents.
    
               This results in:
    
                             .-A---N---O
                            /     /   /
                           I---------D
    
               Note how the rule to only follow the TREESAME parent, if one
               is available, removed **B** from consideration entirely.  **C** was
               considered via **N** , but is TREESAME. Root commits are compared
               to an empty tree, so **I** is !TREESAME.
    
               Parent/child relations are only visible with **--parents** , but
               that does not affect the commits selected in default mode, so
               we have shown the parent lines.
    
           **--full-history** without parent rewriting
               This mode differs from the default in one point: always follow
               all parents of a merge, even if it is TREESAME to one of them.
               Even if more than one side of the merge has commits that are
               included, this does not imply that the merge itself is! In the
               example, we get
    
                           I  A  B  N  D  O  P  Q
    
               **M** was excluded because it is TREESAME to both parents.  **E** , **C**
               and **B** were all walked, but only **B** was !TREESAME, so the others
               do not appear.
    
               Note that without parent rewriting, it is not really possible
               to talk about the parent/child relationships between the
               commits, so we show them disconnected.
    
           **--full-history** with parent rewriting
               Ordinary commits are only included if they are !TREESAME
               (though this can be changed, see **--sparse** below).
    
               Merges are always included. However, their parent list is
               rewritten: Along each parent, prune away commits that are not
               included themselves. This results in
    
                             .-A---M---N---O---P---Q
                            /     /   /   /   /
                           I     B   /   D   /
                            \   /   /   /   /
                             `-------------'
    
               Compare to **--full-history** without rewriting above. Note that **E**
               was pruned away because it is TREESAME, but the parent list of
               P was rewritten to contain **E** 's parent **I**. The same happened for
               **C** and **N** , and **X** , **Y** and **Q**.
    
           In addition to the above settings, you can change whether TREESAME
           affects inclusion:
    
           **--dense**
               Commits that are walked are included if they are not TREESAME
               to any parent.
    
           **--sparse**
               All commits that are walked are included.
    
               Note that without **--full-history** , this still simplifies
               merges: if one of the parents is TREESAME, we follow only that
               one, so the other sides of the merge are never walked.
    
           **--simplify-merges**
               First, build a history graph in the same way that
               **--full-history** with parent rewriting does (see above).
    
               Then simplify each commit **C** to its replacement **C** ' in the final
               history according to the following rules:
    
               •   Set **C** ' to **C**.
    
               •   Replace each parent **P** of **C** ' with its simplification **P** '. In
                   the process, drop parents that are ancestors of other
                   parents or that are root commits TREESAME to an empty
                   tree, and remove duplicates, but take care to never drop
                   all parents that we are TREESAME to.
    
               •   If after this parent rewriting, **C** ' is a root or merge
                   commit (has zero or >1 parents), a boundary commit, or
                   !TREESAME, it remains. Otherwise, it is replaced with its
                   only parent.
    
               The effect of this is best shown by way of comparing to
               **--full-history** with parent rewriting. The example turns into:
    
                             .-A---M---N---O
                            /     /       /
                           I     B       D
                            \   /       /
                             `---------'
    
               Note the major differences in **N** , **P** , and **Q** over **--full-history** :
    
               •   **N** 's parent list had **I** removed, because it is an ancestor
                   of the other parent **M**. Still, **N** remained because it is
                   !TREESAME.
    
               •   **P** 's parent list similarly had **I** removed.  **P** was then
                   removed completely, because it had one parent and is
                   TREESAME.
    
               •   **Q** 's parent list had **Y** simplified to **X**.  **X** was then
                   removed, because it was a TREESAME root.  **Q** was then
                   removed completely, because it had one parent and is
                   TREESAME.
    
           There is another simplification mode available:
    
           **--ancestry-path**[**=**_< commit>_]
               Limit the displayed commits to those which are an ancestor of
               _< commit>_, or which are a descendant of _< commit>_, or are
               _< commit>_ itself.
    
               As an example use case, consider the following commit history:
    
                               D---E-------F
                              /     \       \
                             B---C---G---H---I---J
                            /                     \
                           A-------K---------------L--M
    
               A regular _D..M_ computes the set of commits that are ancestors
               of **M** , but excludes the ones that are ancestors of **D**. This is
               useful to see what happened to the history leading to **M** since
               **D** , in the sense that "what does **M** have that did not exist in
               **D** ". The result in this example would be all the commits,
               except **A** and **B**(and **D** itself, of course).
    
               When we want to find out what commits in **M** are contaminated
               with the bug introduced by **D** and need fixing, however, we
               might want to view only the subset of **D..M** that are actually
               descendants of **D** , i.e. excluding **C** and **K**. This is exactly what
               the **--ancestry-path** option does. Applied to the **D..M** range, it
               results in:
    
                                   E-------F
                                    \       \
                                     G---H---I---J
                                                  \
                                                   L--M
    
               We can also use **--ancestry-path=D** instead of **--ancestry-path**
               which means the same thing when applied to the **D..M** range but
               is just more explicit.
    
               If we instead are interested in a given topic within this
               range, and all commits affected by that topic, we may only
               want to view the subset of **D..M** which contain that topic in
               their ancestry path. So, using **--ancestry-path=H D..M** for
               example would result in:
    
                                   E
                                    \
                                 C---G---H---I---J
                                                  \
                                                   L--M
    
               Whereas **--ancestry-path=K D..M** would result in
    
                                   K---------------L--M
    
           Before discussing another option, **--show-pulls** , we need to create
           a new example history.
    
           A common problem users face when looking at simplified history is
           that a commit they know changed a file somehow does not appear in
           the file’s simplified history. Let’s demonstrate a new example and
           show how options such as **--full-history** and **--simplify-merges**
           works in that case:
    
                         .-A---M-----C--N---O---P
                        /     / \  \  \/   /   /
                       I     B   \  R-'`-Z'   /
                        \   /     \/         /
                         \ /      /\        /
                          `---X--'  `---Y--'
    
           For this example, suppose **I** created **file.txt** which was modified by
           **A** , **B** , and **X** in different ways. The single-parent commits **C** , **Z** , and
           **Y** do not change **file.txt**. The merge commit **M** was created by
           resolving the merge conflict to include both changes from **A** and **B**
           and hence is not TREESAME to either. The merge commit **R** , however,
           was created by ignoring the contents of **file.txt** at **M** and taking
           only the contents of **file.txt** at **X**. Hence, **R** is TREESAME to **X** but
           not **M**. Finally, the natural merge resolution to create **N** is to
           take the contents of **file.txt** at **R** , so **N** is TREESAME to **R** but not
           **C**. The merge commits **O** and **P** are TREESAME to their first parents,
           but not to their second parents, **Z** and **Y** respectively.
    
           When using the default mode, **N** and **R** both have a TREESAME parent,
           so those edges are walked and the others are ignored. The
           resulting history graph is:
    
                       I---X
    
           When using **--full-history** , Git walks every edge. This will
           discover the commits **A** and **B** and the merge **M** , but also will reveal
           the merge commits **O** and **P**. With parent rewriting, the resulting
           graph is:
    
                         .-A---M--------N---O---P
                        /     / \  \  \/   /   /
                       I     B   \  R-'`--'   /
                        \   /     \/         /
                         \ /      /\        /
                          `---X--'  `------'
    
           Here, the merge commits **O** and **P** contribute extra noise, as they
           did not actually contribute a change to **file.txt**. They only merged
           a topic that was based on an older version of **file.txt**. This is a
           common issue in repositories using a workflow where many
           contributors work in parallel and merge their topic branches along
           a single trunk: many unrelated merges appear in the **--full-history**
           results.
    
           When using the **--simplify-merges** option, the commits **O** and **P**
           disappear from the results. This is because the rewritten second
           parents of **O** and **P** are reachable from their first parents. Those
           edges are removed and then the commits look like single-parent
           commits that are TREESAME to their parent. This also happens to
           the commit **N** , resulting in a history view as follows:
    
                         .-A---M--.
                        /     /    \
                       I     B      R
                        \   /      /
                         \ /      /
                          `---X--'
    
           In this view, we see all of the important single-parent changes
           from **A** , **B** , and **X**. We also see the carefully-resolved merge **M** and
           the not-so-carefully-resolved merge **R**. This is usually enough
           information to determine why the commits **A** and **B** "disappeared"
           from history in the default view. However, there are a few issues
           with this approach.
    
           The first issue is performance. Unlike any previous option, the
           **--simplify-merges** option requires walking the entire commit
           history before returning a single result. This can make the option
           difficult to use for very large repositories.
    
           The second issue is one of auditing. When many contributors are
           working on the same repository, it is important which merge
           commits introduced a change into an important branch. The
           problematic merge **R** above is not likely to be the merge commit
           that was used to merge into an important branch. Instead, the
           merge **N** was used to merge **R** and **X** into the important branch. This
           commit may have information about why the change **X** came to
           override the changes from **A** and **B** in its commit message.
    
           **--show-pulls**
               In addition to the commits shown in the default history, show
               each merge commit that is not TREESAME to its first parent but
               is TREESAME to a later parent.
    
               When a merge commit is included by **--show-pulls** , the merge is
               treated as if it "pulled" the change from another branch. When
               using **--show-pulls** on this example (and no other options) the
               resulting graph is:
    
                           I---X---R---N
    
               Here, the merge commits **R** and **N** are included because they
               pulled the commits **X** and **R** into the base branch, respectively.
               These merges are the reason the commits **A** and **B** do not appear
               in the default history.
    
               When **--show-pulls** is paired with **--simplify-merges** , the graph
               includes all of the necessary information:
    
                             .-A---M--.   N
                            /     /    \ /
                           I     B      R
                            \   /      /
                             \ /      /
                              `---X--'
    
               Notice that since **M** is reachable from **R** , the edge from **N** to **M**
               was simplified away. However, **N** still appears in the history
               as an important commit because it "pulled" the change **R** into
               the main branch.
    
           The **--simplify-by-decoration** option allows you to view only the
           big picture of the topology of the history, by omitting commits
           that are not referenced by tags. Commits are marked as !TREESAME
           (in other words, kept after history simplification rules described
           above) if (1) they are referenced by tags, or (2) they change the
           contents of the paths given on the command line. All other commits
           are marked as TREESAME (subject to be simplified away).
    


## GIT



           Part of the git(1) suite
    


* * *