Merge branch 'je/doc-rebase'

Documentation for "git rebase" has been updated.

* je/doc-rebase:
  doc: git-rebase: update discussion of internals
  doc: git-rebase: move --onto explanation down
  doc: git rebase: clarify arguments syntax
  doc: git rebase: dedup merge conflict discussion
  doc: git-rebase: start with an example

Author: gitster

Documentation/git-rebase.adoc

@@ -16,94 +16,81 @@ SYNOPSIS
 
 DESCRIPTION
 -----------
-If `<branch>` is specified, `git rebase` will perform an automatic
-`git switch <branch>` before doing anything else.  Otherwise
-it remains on the current branch.
+Transplant a series of commits onto a different starting point.
+You can also use `git rebase` to reorder or combine commits: see INTERACTIVE
+MODE below for how to do that.
 
-If `<upstream>` is not specified, the upstream configured in
-`branch.<name>.remote` and `branch.<name>.merge` options will be used (see
-linkgit:git-config[1] for details) and the `--fork-point` option is
-assumed.  If you are currently not on any branch or if the current
-branch does not have a configured upstream, the rebase will abort.
-
-All changes made by commits in the current branch but that are not
-in `<upstream>` are saved to a temporary area.  This is the same set
-of commits that would be shown by `git log <upstream>..HEAD`; or by
-`git log 'fork_point'..HEAD`, if `--fork-point` is active (see the
-description on `--fork-point` below); or by `git log HEAD`, if the
-`--root` option is specified.
-
-The current branch is reset to `<upstream>` or `<newbase>` if the
-`--onto` option was supplied.  This has the exact same effect as
-`git reset --hard <upstream>` (or `<newbase>`). `ORIG_HEAD` is set
-to point at the tip of the branch before the reset.
-
-[NOTE]
-`ORIG_HEAD` is not guaranteed to still point to the previous branch tip
-at the end of the rebase if other commands that write that pseudo-ref
-(e.g. `git reset`) are used during the rebase. The previous branch tip,
-however, is accessible using the reflog of the current branch
-(i.e. `@{1}`, see linkgit:gitrevisions[7]).
-
-The commits that were previously saved into the temporary area are
-then reapplied to the current branch, one by one, in order. Note that
-any commits in `HEAD` which introduce the same textual changes as a commit
-in `HEAD..<upstream>` are omitted (i.e., a patch already accepted upstream
-with a different commit message or timestamp will be skipped).
-
-It is possible that a merge failure will prevent this process from being
-completely automatic.  You will have to resolve any such merge failure
-and run `git rebase --continue`.  Another option is to bypass the commit
-that caused the merge failure with `git rebase --skip`.  To check out the
-original `<branch>` and remove the `.git/rebase-apply` working files, use
-the command `git rebase --abort` instead.
-
-Assume the following history exists and the current branch is "topic":
+For example, imagine that you have been working on the `topic` branch in this
+history, and you want to "catch up" to the work done on the `master` branch.
 
 ------------
           A---B---C topic
          /
     D---E---F---G master
 ------------
 
-From this point, the result of either of the following commands:
-
-
-    git rebase master
-    git rebase master topic
-
-would be:
+You want to transplant the commits you made on `topic` since it diverged from
+`master` (i.e. A, B, and C), on top of the current `master`.  You can do this
+by running `git rebase master` while the `topic` branch is checked out.  If you
+want to rebase `topic` while on another branch, `git rebase master topic` is a
+shortcut for `git checkout topic && git rebase master`.
 
 ------------
                   A'--B'--C' topic
                  /
     D---E---F---G master
 ------------
 
-*NOTE:* The latter form is just a short-hand of `git checkout topic`
-followed by `git rebase master`. When rebase exits `topic` will
-remain the checked-out branch.
 
-If the upstream branch already contains a change you have made (e.g.,
-because you mailed a patch which was applied upstream), then that commit
-will be skipped and warnings will be issued (if the 'merge' backend is
-used).  For example, running `git rebase master` on the following
-history (in which `A'` and `A` introduce the same set of changes, but
-have different committer information):
+If there is a merge conflict during this process, `git rebase` will stop at the
+first problematic commit and leave conflict markers. If this happens, you can do
+one of these things:
 
-------------
-          A---B---C topic
-         /
-    D---E---A'---F master
-------------
+1. Resolve the conflict. You can use `git diff` to find the markers (<<<<<<)
+   and make edits to resolve the conflict. For each file you edit, you need to
+   tell Git that the conflict has been resolved. You can mark the conflict as
+   resolved with  `git add <filename>`. After resolving all of the conflicts,
+   you can continue the rebasing process with
 
-will result in:
+   git rebase --continue
 
-------------
-                   B'---C' topic
-                  /
-    D---E---A'---F master
-------------
+2. Stop the `git rebase` and return your branch to its original state with
+
+   git rebase --abort
+
+3. Skip the commit that caused the merge conflict with
+
+   git rebase --skip
+
+If you don't specify an `<upstream>` to rebase onto, the upstream configured in
+`branch.<name>.remote` and `branch.<name>.merge` options will be used (see
+linkgit:git-config[1] for details) and the `--fork-point` option is
+assumed.  If you are currently not on any branch or if the current
+branch does not have a configured upstream, the rebase will abort.
+
+Here is a simplified description of what `git rebase <upstream>` does:
+
+1. Make a list of all commits on your current branch since it branched
+   off from `<upstream>` that do not have an equivalent commit in
+   `<upstream>`.
+2. Check out `<upstream>` with the equivalent of
+   `git checkout --detach <upstream>`.
+3. Replay the commits, one by one, in order. This is similar to running
+   `git cherry-pick <commit>` for each commit. See REBASING MERGES for how merges
+   are handled.
+4. Update your branch to point to the final commit with the equivalent
+   of `git checkout -B <branch>`.
+
+[NOTE]
+When starting the rebase, `ORIG_HEAD` is set to point to the commit at the tip
+of the to-be-rebased branch. However, `ORIG_HEAD` is not guaranteed to still
+point to that commit at the end of the rebase if other commands that change
+`ORIG_HEAD` (like `git reset`) are used during the rebase. The previous branch
+tip, however, is accessible using the reflog of the current branch (i.e. `@{1}`,
+see linkgit:gitrevisions[7].
+
+TRANSPLANTING A TOPIC BRANCH WITH --ONTO
+----------------------------------------
 
 Here is how you would transplant a topic branch based on one
 branch to another, to pretend that you forked the topic branch
@@ -186,28 +173,6 @@ This is useful if F and G were flawed in some way, or should not be
 part of topicA.  Note that the argument to `--onto` and the `<upstream>`
 parameter can be any valid commit-ish.
 
-In case of conflict, `git rebase` will stop at the first problematic commit
-and leave conflict markers in the tree.  You can use `git diff` to locate
-the markers (<<<<<<) and make edits to resolve the conflict.  For each
-file you edit, you need to tell Git that the conflict has been resolved,
-typically this would be done with
-
-
-    git add <filename>
-
-
-After resolving the conflict manually and updating the index with the
-desired resolution, you can continue the rebasing process with
-
-
-    git rebase --continue
-
-
-Alternatively, you can undo the 'git rebase' with
-
-
-    git rebase --abort
-
 MODE OPTIONS
 ------------
 
@@ -253,6 +218,8 @@ As a special case, you may use "A\...B" as a shortcut for the
 merge base of A and B if there is exactly one merge base. You can
 leave out at most one of A and B, in which case it defaults to HEAD.
 
+See TRANSPLANTING A TOPIC BRANCH WITH --ONTO above for examples.
+
 --keep-base::
 	Set the starting point at which to create the new commits to the
 	merge base of `<upstream>` and `<branch>`. Running