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-git-range-diff(1)
-=================
-
-NAME
-----
-git-range-diff - Compare two commit ranges (e.g. two versions of a branch)
-
-SYNOPSIS
---------
-[verse]
-'git range-diff' [--color=[<when>]] [--no-color] [<diff-options>]
-	[--no-dual-color] [--creation-factor=<factor>]
-	( <range1> <range2> | <rev1>...<rev2> | <base> <rev1> <rev2> )
-
-DESCRIPTION
------------
-
-This command shows the differences between two versions of a patch
-series, or more generally, two commit ranges (ignoring merge commits).
-
-To that end, it first finds pairs of commits from both commit ranges
-that correspond with each other. Two commits are said to correspond when
-the diff between their patches (i.e. the author information, the commit
-message and the commit diff) is reasonably small compared to the
-patches' size. See ``Algorithm`` below for details.
-
-Finally, the list of matching commits is shown in the order of the
-second commit range, with unmatched commits being inserted just after
-all of their ancestors have been shown.
-
-
-OPTIONS
--------
---no-dual-color::
-	When the commit diffs differ, `git range-diff` recreates the
-	original diffs' coloring, and adds outer -/+ diff markers with
-	the *background* being red/green to make it easier to see e.g.
-	when there was a change in what exact lines were added.
-+
-Additionally, the commit diff lines that are only present in the first commit
-range are shown "dimmed" (this can be overridden using the `color.diff.<slot>`
-config setting where `<slot>` is one of `contextDimmed`, `oldDimmed` and
-`newDimmed`), and the commit diff lines that are only present in the second
-commit range are shown in bold (which can be overridden using the config
-settings `color.diff.<slot>` with `<slot>` being one of `contextBold`,
-`oldBold` or `newBold`).
-+
-This is known to `range-diff` as "dual coloring". Use `--no-dual-color`
-to revert to color all lines according to the outer diff markers
-(and completely ignore the inner diff when it comes to color).
-
---creation-factor=<percent>::
-	Set the creation/deletion cost fudge factor to `<percent>`.
-	Defaults to 60. Try a larger value if `git range-diff` erroneously
-	considers a large change a total rewrite (deletion of one commit
-	and addition of another), and a smaller one in the reverse case.
-	See the ``Algorithm`` section below for an explanation why this is
-	needed.
-
---[no-]notes[=<ref>]::
-	This flag is passed to the `git log` program
-	(see linkgit:git-log[1]) that generates the patches.
-
-<range1> <range2>::
-	Compare the commits specified by the two ranges, where
-	`<range1>` is considered an older version of `<range2>`.
-
-<rev1>...<rev2>::
-	Equivalent to passing `<rev2>..<rev1>` and `<rev1>..<rev2>`.
-
-<base> <rev1> <rev2>::
-	Equivalent to passing `<base>..<rev1>` and `<base>..<rev2>`.
-	Note that `<base>` does not need to be the exact branch point
-	of the branches. Example: after rebasing a branch `my-topic`,
-	`git range-diff my-topic@{u} my-topic@{1} my-topic` would
-	show the differences introduced by the rebase.
-
-`git range-diff` also accepts the regular diff options (see
-linkgit:git-diff[1]), most notably the `--color=[<when>]` and
-`--no-color` options. These options are used when generating the "diff
-between patches", i.e. to compare the author, commit message and diff of
-corresponding old/new commits. There is currently no means to tweak most of the
-diff options passed to `git log` when generating those patches.
-
-OUTPUT STABILITY
-----------------
-
-The output of the `range-diff` command is subject to change. It is
-intended to be human-readable porcelain output, not something that can
-be used across versions of Git to get a textually stable `range-diff`
-(as opposed to something like the `--stable` option to
-linkgit:git-patch-id[1]). There's also no equivalent of
-linkgit:git-apply[1] for `range-diff`, the output is not intended to
-be machine-readable.
-
-This is particularly true when passing in diff options. Currently some
-options like `--stat` can, as an emergent effect, produce output
-that's quite useless in the context of `range-diff`. Future versions
-of `range-diff` may learn to interpret such options in a manner
-specific to `range-diff` (e.g. for `--stat` producing human-readable
-output which summarizes how the diffstat changed).
-
-CONFIGURATION
--------------
-This command uses the `diff.color.*` and `pager.range-diff` settings
-(the latter is on by default).
-See linkgit:git-config[1].
-
-
-EXAMPLES
---------
-
-When a rebase required merge conflicts to be resolved, compare the changes
-introduced by the rebase directly afterwards using:
-
-------------
-$ git range-diff @{u} @{1} @
-------------
-
-
-A typical output of `git range-diff` would look like this:
-
-------------
--:  ------- > 1:  0ddba11 Prepare for the inevitable!
-1:  c0debee = 2:  cab005e Add a helpful message at the start
-2:  f00dbal ! 3:  decafe1 Describe a bug
-    @@ -1,3 +1,3 @@
-     Author: A U Thor <author@example.com>
-
-    -TODO: Describe a bug
-    +Describe a bug
-    @@ -324,5 +324,6
-      This is expected.
-
-    -+What is unexpected is that it will also crash.
-    ++Unexpectedly, it also crashes. This is a bug, and the jury is
-    ++still out there how to fix it best. See ticket #314 for details.
-
-      Contact
-3:  bedead < -:  ------- TO-UNDO
-------------
-
-In this example, there are 3 old and 3 new commits, where the developer
-removed the 3rd, added a new one before the first two, and modified the
-commit message of the 2nd commit as well its diff.
-
-When the output goes to a terminal, it is color-coded by default, just
-like regular `git diff`'s output. In addition, the first line (adding a
-commit) is green, the last line (deleting a commit) is red, the second
-line (with a perfect match) is yellow like the commit header of `git
-show`'s output, and the third line colors the old commit red, the new
-one green and the rest like `git show`'s commit header.
-
-A naive color-coded diff of diffs is actually a bit hard to read,
-though, as it colors the entire lines red or green. The line that added
-"What is unexpected" in the old commit, for example, is completely red,
-even if the intent of the old commit was to add something.
-
-To help with that, `range` uses the `--dual-color` mode by default. In
-this mode, the diff of diffs will retain the original diff colors, and
-prefix the lines with -/+ markers that have their *background* red or
-green, to make it more obvious that they describe how the diff itself
-changed.
-
-
-Algorithm
----------
-
-The general idea is this: we generate a cost matrix between the commits
-in both commit ranges, then solve the least-cost assignment.
-
-The cost matrix is populated thusly: for each pair of commits, both
-diffs are generated and the "diff of diffs" is generated, with 3 context
-lines, then the number of lines in that diff is used as cost.
-
-To avoid false positives (e.g. when a patch has been removed, and an
-unrelated patch has been added between two iterations of the same patch
-series), the cost matrix is extended to allow for that, by adding
-fixed-cost entries for wholesale deletes/adds.
-
-Example: Let commits `1--2` be the first iteration of a patch series and
-`A--C` the second iteration. Let's assume that `A` is a cherry-pick of
-`2,` and `C` is a cherry-pick of `1` but with a small modification (say,
-a fixed typo). Visualize the commits as a bipartite graph:
-
-------------
-    1            A
-
-    2            B
-
-		 C
-------------
-
-We are looking for a "best" explanation of the new series in terms of
-the old one. We can represent an "explanation" as an edge in the graph:
-
-
-------------
-    1            A
-	       /
-    2 --------'  B
-
-		 C
-------------
-
-This explanation comes for "free" because there was no change. Similarly
-`C` could be explained using `1`, but that comes at some cost c>0
-because of the modification:
-
-------------
-    1 ----.      A
-	  |    /
-    2 ----+---'  B
-	  |
-	  `----- C
-	  c>0
-------------
-
-In mathematical terms, what we are looking for is some sort of a minimum
-cost bipartite matching; `1` is matched to `C` at some cost, etc. The
-underlying graph is in fact a complete bipartite graph; the cost we
-associate with every edge is the size of the diff between the two
-commits' patches. To explain also new commits, we introduce dummy nodes
-on both sides:
-
-------------
-    1 ----.      A
-	  |    /
-    2 ----+---'  B
-	  |
-    o     `----- C
-	  c>0
-    o            o
-
-    o            o
-------------
-
-The cost of an edge `o--C` is the size of `C`'s diff, modified by a
-fudge factor that should be smaller than 100%. The cost of an edge
-`o--o` is free. The fudge factor is necessary because even if `1` and
-`C` have nothing in common, they may still share a few empty lines and
-such, possibly making the assignment `1--C`, `o--o` slightly cheaper
-than `1--o`, `o--C` even if `1` and `C` have nothing in common. With the
-fudge factor we require a much larger common part to consider patches as
-corresponding.
-
-The overall time needed to compute this algorithm is the time needed to
-compute n+m commit diffs and then n*m diffs of patches, plus the time
-needed to compute the least-cost assignment between n and m diffs. Git
-uses an implementation of the Jonker-Volgenant algorithm to solve the
-assignment problem, which has cubic runtime complexity. The matching
-found in this case will look like this:
-
-------------
-    1 ----.      A
-	  |    /
-    2 ----+---'  B
-       .--+-----'
-    o -'  `----- C
-	  c>0
-    o ---------- o
-
-    o ---------- o
-------------
-
-
-SEE ALSO
---------
-linkgit:git-log[1]
-
-GIT
----
-Part of the linkgit:git[1] suite