Merge branch 'mg/reset-doc'

* mg/reset-doc:
  git-reset.txt: make modes description more consistent
  git-reset.txt: point to git-checkout
  git-reset.txt: use "working tree" consistently
  git-reset.txt: reset --soft is not a no-op
  git-reset.txt: reset does not change files in target
  git-reset.txt: clarify branch vs. branch head

Author: gitster

Documentation/git-reset.txt

@@ -15,17 +15,24 @@ SYNOPSIS
 DESCRIPTION
 -----------
 In the first and second form, copy entries from <commit> to the index.
-In the third form, set the current branch to <commit>, optionally
-modifying index and worktree to match.  The <commit> defaults to HEAD
+In the third form, set the current branch head (HEAD) to <commit>, optionally
+modifying index and working tree to match.  The <commit> defaults to HEAD
 in all forms.
 
 'git reset' [-q] [<commit>] [--] <paths>...::
 	This form resets the index entries for all <paths> to their
-	state at the <commit>.  (It does not affect the worktree, nor
+	state at <commit>.  (It does not affect the working tree, nor
 	the current branch.)
 +
 This means that `git reset <paths>` is the opposite of `git add
 <paths>`.
++
+After running `git reset <paths>` to update the index entry, you can
+use linkgit:git-checkout[1] to check the contents out of the index to
+the working tree.
+Alternatively, using linkgit:git-checkout[1] and specifying a commit, you
+can copy the contents of a path out of a commit to the index and to the
+working tree in one go.
 
 'git reset' --patch|-p [<commit>] [--] [<paths>...]::
 	Interactively select hunks in the difference between the index
@@ -36,39 +43,48 @@ This means that `git reset -p` is the opposite of `git add -p` (see
 linkgit:git-add[1]).
 
 'git reset' [--<mode>] [<commit>]::
-	This form points the current branch to <commit> and then
-	updates index and working tree according to <mode>, which must
-	be one of the following:
+	This form resets the current branch head to <commit> and
+	possibly updates the index (resetting it to the tree of <commit>) and
+	the working tree depending on <mode>, which
+	must be one of the following:
 +
 --
 --soft::
-	Does not touch the index file nor the working tree at all, but
-	requires them to be in a good order. This leaves all your changed
-	files "Changes to be committed", as 'git status' would
-	put it.
+	Does not touch the index file nor the working tree at all (but
+	resets the head to <commit>, just like all modes do). This leaves
+	all your changed files "Changes to be committed", as 'git status'
+	would put it.
 
 --mixed::
 	Resets the index but not the working tree (i.e., the changed files
 	are preserved but not marked for commit) and reports what has not
 	been updated. This is the default action.
 
 --hard::
-	Matches the working tree and index to that of the tree being
-	switched to. Any changes to tracked files in the working tree
-	since <commit> are lost.
+	Resets the index and working tree. Any changes to tracked files in the
+	working tree since <commit> are discarded.
 
 --merge::
-	Resets the index to match the tree recorded by the named commit,
-	and updates the files that are different between the named commit
-	and the current commit in the working tree.
+	Resets the index and updates the files in the working tree that are
+	different between <commit> and HEAD, but keeps those which are
+	different between the index and working tree (i.e. which have changes
+	which have not been added).
+	If a file that is different between <commit> and the index has unstaged
+	changes, reset is aborted.
++
+In other words, --merge does something like a 'git read-tree -u -m <commit>',
+but carries forward unmerged index entries.
 
 --keep::
-	Reset the index to the given commit, keeping local changes in
-	the working tree since the current commit, while updating
-	working tree files without local changes to what appears in
-	the given commit.  If a file that is different between the
-	current commit and the given commit has local changes, reset
-	is aborted.
+	Resets the index, updates files in the working tree that are
+	different between <commit> and HEAD, but keeps those
+	which are different between HEAD and the working tree (i.e.
+	which have local changes).
+	If a file that is different between <commit> and HEAD has local changes,
+	reset is aborted.
++
+In other words, --keep does a 2-way merge between <commit> and HEAD followed by
+'git reset --mixed <commit>'.
 --
 
 If you want to undo a commit other than the latest on a branch,
@@ -184,7 +200,7 @@ tip of the current branch in ORIG_HEAD, so resetting hard to it
 brings your index file and the working tree back to that state,
 and resets the tip of the branch to that commit.
 
-Undo a merge or pull inside a dirty work tree::
+Undo a merge or pull inside a dirty working tree::
 +
 ------------
 $ git pull                         <1>
@@ -257,7 +273,7 @@ Suppose you are working on something and you commit it, and then you
 continue working a bit more, but now you think that what you have in
 your working tree should be in another branch that has nothing to do
 with what you committed previously. You can start a new branch and
-reset it while keeping the changes in your work tree.
+reset it while keeping the changes in your working tree.
 +
 ------------
 $ git tag start
@@ -294,8 +310,10 @@ In these tables, A, B, C and D are some different states of a
 file. For example, the first line of the first table means that if a
 file is in state A in the working tree, in state B in the index, in
 state C in HEAD and in state D in the target, then "git reset --soft
-target" will put the file in state A in the working tree, in state B
-in the index and in state D in HEAD.
+target" will leave the file in the working tree in state A and in the
+index in state B.  It resets (i.e. moves) the HEAD (i.e. the tip of
+the current branch, if you are on one) to "target" (which has the file
+in state D).
 
       working index HEAD target         working index HEAD
       ----------------------------------------------------
@@ -346,11 +364,11 @@ in the index and in state D in HEAD.
 				--keep   B       C     C
 
 "reset --merge" is meant to be used when resetting out of a conflicted
-merge. Any mergy operation guarantees that the work tree file that is
+merge. Any mergy operation guarantees that the working tree file that is
 involved in the merge does not have local change wrt the index before
-it starts, and that it writes the result out to the work tree. So if
+it starts, and that it writes the result out to the working tree. So if
 we see some difference between the index and the target and also
-between the index and the work tree, then it means that we are not
+between the index and the working tree, then it means that we are not
 resetting out from a state that a mergy operation left after failing
 with a conflict. That is why we disallow --merge option in this case.