Documentation / git-reset.txton commit doc: give some guidelines for error messages (0ae0e88)
   1git-reset(1)
   2============
   3
   4NAME
   5----
   6git-reset - Reset current HEAD to the specified state
   7
   8SYNOPSIS
   9--------
  10[verse]
  11'git reset' [-q] [<tree-ish>] [--] <paths>...
  12'git reset' (--patch | -p) [<tree-ish>] [--] [<paths>...]
  13'git reset' [--soft | --mixed [-N] | --hard | --merge | --keep] [-q] [<commit>]
  14
  15DESCRIPTION
  16-----------
  17In the first and second form, copy entries from <tree-ish> to the index.
  18In the third form, set the current branch head (HEAD) to <commit>, optionally
  19modifying index and working tree to match.  The <tree-ish>/<commit> defaults
  20to HEAD in all forms.
  21
  22'git reset' [-q] [<tree-ish>] [--] <paths>...::
  23        This form resets the index entries for all <paths> to their
  24        state at <tree-ish>.  (It does not affect the working tree or
  25        the current branch.)
  26+
  27This means that `git reset <paths>` is the opposite of `git add
  28<paths>`.
  29+
  30After running `git reset <paths>` to update the index entry, you can
  31use linkgit:git-checkout[1] to check the contents out of the index to
  32the working tree.
  33Alternatively, using linkgit:git-checkout[1] and specifying a commit, you
  34can copy the contents of a path out of a commit to the index and to the
  35working tree in one go.
  36
  37'git reset' (--patch | -p) [<tree-ish>] [--] [<paths>...]::
  38        Interactively select hunks in the difference between the index
  39        and <tree-ish> (defaults to HEAD).  The chosen hunks are applied
  40        in reverse to the index.
  41+
  42This means that `git reset -p` is the opposite of `git add -p`, i.e.
  43you can use it to selectively reset hunks. See the ``Interactive Mode''
  44section of linkgit:git-add[1] to learn how to operate the `--patch` mode.
  45
  46'git reset' [<mode>] [<commit>]::
  47        This form resets the current branch head to <commit> and
  48        possibly updates the index (resetting it to the tree of <commit>) and
  49        the working tree depending on <mode>. If <mode> is omitted,
  50        defaults to "--mixed". The <mode> must be one of the following:
  51+
  52--
  53--soft::
  54        Does not touch the index file or the working tree at all (but
  55        resets the head to <commit>, just like all modes do). This leaves
  56        all your changed files "Changes to be committed", as 'git status'
  57        would put it.
  58
  59--mixed::
  60        Resets the index but not the working tree (i.e., the changed files
  61        are preserved but not marked for commit) and reports what has not
  62        been updated. This is the default action.
  63+
  64If `-N` is specified, removed paths are marked as intent-to-add (see
  65linkgit:git-add[1]).
  66
  67--hard::
  68        Resets the index and working tree. Any changes to tracked files in the
  69        working tree since <commit> are discarded.
  70
  71--merge::
  72        Resets the index and updates the files in the working tree that are
  73        different between <commit> and HEAD, but keeps those which are
  74        different between the index and working tree (i.e. which have changes
  75        which have not been added).
  76        If a file that is different between <commit> and the index has unstaged
  77        changes, reset is aborted.
  78+
  79In other words, --merge does something like a 'git read-tree -u -m <commit>',
  80but carries forward unmerged index entries.
  81
  82--keep::
  83        Resets index entries and updates files in the working tree that are
  84        different between <commit> and HEAD.
  85        If a file that is different between <commit> and HEAD has local changes,
  86        reset is aborted.
  87--
  88
  89If you want to undo a commit other than the latest on a branch,
  90linkgit:git-revert[1] is your friend.
  91
  92
  93OPTIONS
  94-------
  95
  96-q::
  97--quiet::
  98        Be quiet, only report errors.
  99
 100
 101EXAMPLES
 102--------
 103
 104Undo add::
 105+
 106------------
 107$ edit                                     <1>
 108$ git add frotz.c filfre.c
 109$ mailx                                    <2>
 110$ git reset                                <3>
 111$ git pull git://info.example.com/ nitfol  <4>
 112------------
 113+
 114<1> You are happily working on something, and find the changes
 115in these files are in good order.  You do not want to see them
 116when you run "git diff", because you plan to work on other files
 117and changes with these files are distracting.
 118<2> Somebody asks you to pull, and the changes sounds worthy of merging.
 119<3> However, you already dirtied the index (i.e. your index does
 120not match the HEAD commit).  But you know the pull you are going
 121to make does not affect frotz.c or filfre.c, so you revert the
 122index changes for these two files.  Your changes in working tree
 123remain there.
 124<4> Then you can pull and merge, leaving frotz.c and filfre.c
 125changes still in the working tree.
 126
 127Undo a commit and redo::
 128+
 129------------
 130$ git commit ...
 131$ git reset --soft HEAD^      <1>
 132$ edit                        <2>
 133$ git commit -a -c ORIG_HEAD  <3>
 134------------
 135+
 136<1> This is most often done when you remembered what you
 137just committed is incomplete, or you misspelled your commit
 138message, or both.  Leaves working tree as it was before "reset".
 139<2> Make corrections to working tree files.
 140<3> "reset" copies the old head to .git/ORIG_HEAD; redo the
 141commit by starting with its log message.  If you do not need to
 142edit the message further, you can give -C option instead.
 143+
 144See also the --amend option to linkgit:git-commit[1].
 145
 146Undo a commit, making it a topic branch::
 147+
 148------------
 149$ git branch topic/wip     <1>
 150$ git reset --hard HEAD~3  <2>
 151$ git checkout topic/wip   <3>
 152------------
 153+
 154<1> You have made some commits, but realize they were premature
 155to be in the "master" branch.  You want to continue polishing
 156them in a topic branch, so create "topic/wip" branch off of the
 157current HEAD.
 158<2> Rewind the master branch to get rid of those three commits.
 159<3> Switch to "topic/wip" branch and keep working.
 160
 161Undo commits permanently::
 162+
 163------------
 164$ git commit ...
 165$ git reset --hard HEAD~3   <1>
 166------------
 167+
 168<1> The last three commits (HEAD, HEAD^, and HEAD~2) were bad
 169and you do not want to ever see them again.  Do *not* do this if
 170you have already given these commits to somebody else.  (See the
 171"RECOVERING FROM UPSTREAM REBASE" section in linkgit:git-rebase[1] for
 172the implications of doing so.)
 173
 174Undo a merge or pull::
 175+
 176------------
 177$ git pull                         <1>
 178Auto-merging nitfol
 179CONFLICT (content): Merge conflict in nitfol
 180Automatic merge failed; fix conflicts and then commit the result.
 181$ git reset --hard                 <2>
 182$ git pull . topic/branch          <3>
 183Updating from 41223... to 13134...
 184Fast-forward
 185$ git reset --hard ORIG_HEAD       <4>
 186------------
 187+
 188<1> Try to update from the upstream resulted in a lot of
 189conflicts; you were not ready to spend a lot of time merging
 190right now, so you decide to do that later.
 191<2> "pull" has not made merge commit, so "git reset --hard"
 192which is a synonym for "git reset --hard HEAD" clears the mess
 193from the index file and the working tree.
 194<3> Merge a topic branch into the current branch, which resulted
 195in a fast-forward.
 196<4> But you decided that the topic branch is not ready for public
 197consumption yet.  "pull" or "merge" always leaves the original
 198tip of the current branch in ORIG_HEAD, so resetting hard to it
 199brings your index file and the working tree back to that state,
 200and resets the tip of the branch to that commit.
 201
 202Undo a merge or pull inside a dirty working tree::
 203+
 204------------
 205$ git pull                         <1>
 206Auto-merging nitfol
 207Merge made by recursive.
 208 nitfol                |   20 +++++----
 209 ...
 210$ git reset --merge ORIG_HEAD      <2>
 211------------
 212+
 213<1> Even if you may have local modifications in your
 214working tree, you can safely say "git pull" when you know
 215that the change in the other branch does not overlap with
 216them.
 217<2> After inspecting the result of the merge, you may find
 218that the change in the other branch is unsatisfactory.  Running
 219"git reset --hard ORIG_HEAD" will let you go back to where you
 220were, but it will discard your local changes, which you do not
 221want.  "git reset --merge" keeps your local changes.
 222
 223
 224Interrupted workflow::
 225+
 226Suppose you are interrupted by an urgent fix request while you
 227are in the middle of a large change.  The files in your
 228working tree are not in any shape to be committed yet, but you
 229need to get to the other branch for a quick bugfix.
 230+
 231------------
 232$ git checkout feature ;# you were working in "feature" branch and
 233$ work work work       ;# got interrupted
 234$ git commit -a -m "snapshot WIP"                 <1>
 235$ git checkout master
 236$ fix fix fix
 237$ git commit ;# commit with real log
 238$ git checkout feature
 239$ git reset --soft HEAD^ ;# go back to WIP state  <2>
 240$ git reset                                       <3>
 241------------
 242+
 243<1> This commit will get blown away so a throw-away log message is OK.
 244<2> This removes the 'WIP' commit from the commit history, and sets
 245    your working tree to the state just before you made that snapshot.
 246<3> At this point the index file still has all the WIP changes you
 247    committed as 'snapshot WIP'.  This updates the index to show your
 248    WIP files as uncommitted.
 249+
 250See also linkgit:git-stash[1].
 251
 252Reset a single file in the index::
 253+
 254Suppose you have added a file to your index, but later decide you do not
 255want to add it to your commit. You can remove the file from the index
 256while keeping your changes with git reset.
 257+
 258------------
 259$ git reset -- frotz.c                      <1>
 260$ git commit -m "Commit files in index"     <2>
 261$ git add frotz.c                           <3>
 262------------
 263+
 264<1> This removes the file from the index while keeping it in the working
 265    directory.
 266<2> This commits all other changes in the index.
 267<3> Adds the file to the index again.
 268
 269Keep changes in working tree while discarding some previous commits::
 270+
 271Suppose you are working on something and you commit it, and then you
 272continue working a bit more, but now you think that what you have in
 273your working tree should be in another branch that has nothing to do
 274with what you committed previously. You can start a new branch and
 275reset it while keeping the changes in your working tree.
 276+
 277------------
 278$ git tag start
 279$ git checkout -b branch1
 280$ edit
 281$ git commit ...                            <1>
 282$ edit
 283$ git checkout -b branch2                   <2>
 284$ git reset --keep start                    <3>
 285------------
 286+
 287<1> This commits your first edits in branch1.
 288<2> In the ideal world, you could have realized that the earlier
 289    commit did not belong to the new topic when you created and switched
 290    to branch2 (i.e. "git checkout -b branch2 start"), but nobody is
 291    perfect.
 292<3> But you can use "reset --keep" to remove the unwanted commit after
 293    you switched to "branch2".
 294
 295
 296DISCUSSION
 297----------
 298
 299The tables below show what happens when running:
 300
 301----------
 302git reset --option target
 303----------
 304
 305to reset the HEAD to another commit (`target`) with the different
 306reset options depending on the state of the files.
 307
 308In these tables, A, B, C and D are some different states of a
 309file. For example, the first line of the first table means that if a
 310file is in state A in the working tree, in state B in the index, in
 311state C in HEAD and in state D in the target, then "git reset --soft
 312target" will leave the file in the working tree in state A and in the
 313index in state B.  It resets (i.e. moves) the HEAD (i.e. the tip of
 314the current branch, if you are on one) to "target" (which has the file
 315in state D).
 316
 317      working index HEAD target         working index HEAD
 318      ----------------------------------------------------
 319       A       B     C    D     --soft   A       B     D
 320                                --mixed  A       D     D
 321                                --hard   D       D     D
 322                                --merge (disallowed)
 323                                --keep  (disallowed)
 324
 325      working index HEAD target         working index HEAD
 326      ----------------------------------------------------
 327       A       B     C    C     --soft   A       B     C
 328                                --mixed  A       C     C
 329                                --hard   C       C     C
 330                                --merge (disallowed)
 331                                --keep   A       C     C
 332
 333      working index HEAD target         working index HEAD
 334      ----------------------------------------------------
 335       B       B     C    D     --soft   B       B     D
 336                                --mixed  B       D     D
 337                                --hard   D       D     D
 338                                --merge  D       D     D
 339                                --keep  (disallowed)
 340
 341      working index HEAD target         working index HEAD
 342      ----------------------------------------------------
 343       B       B     C    C     --soft   B       B     C
 344                                --mixed  B       C     C
 345                                --hard   C       C     C
 346                                --merge  C       C     C
 347                                --keep   B       C     C
 348
 349      working index HEAD target         working index HEAD
 350      ----------------------------------------------------
 351       B       C     C    D     --soft   B       C     D
 352                                --mixed  B       D     D
 353                                --hard   D       D     D
 354                                --merge (disallowed)
 355                                --keep  (disallowed)
 356
 357      working index HEAD target         working index HEAD
 358      ----------------------------------------------------
 359       B       C     C    C     --soft   B       C     C
 360                                --mixed  B       C     C
 361                                --hard   C       C     C
 362                                --merge  B       C     C
 363                                --keep   B       C     C
 364
 365"reset --merge" is meant to be used when resetting out of a conflicted
 366merge. Any mergy operation guarantees that the working tree file that is
 367involved in the merge does not have local change wrt the index before
 368it starts, and that it writes the result out to the working tree. So if
 369we see some difference between the index and the target and also
 370between the index and the working tree, then it means that we are not
 371resetting out from a state that a mergy operation left after failing
 372with a conflict. That is why we disallow --merge option in this case.
 373
 374"reset --keep" is meant to be used when removing some of the last
 375commits in the current branch while keeping changes in the working
 376tree. If there could be conflicts between the changes in the commit we
 377want to remove and the changes in the working tree we want to keep,
 378the reset is disallowed. That's why it is disallowed if there are both
 379changes between the working tree and HEAD, and between HEAD and the
 380target. To be safe, it is also disallowed when there are unmerged
 381entries.
 382
 383The following tables show what happens when there are unmerged
 384entries:
 385
 386      working index HEAD target         working index HEAD
 387      ----------------------------------------------------
 388       X       U     A    B     --soft  (disallowed)
 389                                --mixed  X       B     B
 390                                --hard   B       B     B
 391                                --merge  B       B     B
 392                                --keep  (disallowed)
 393
 394      working index HEAD target         working index HEAD
 395      ----------------------------------------------------
 396       X       U     A    A     --soft  (disallowed)
 397                                --mixed  X       A     A
 398                                --hard   A       A     A
 399                                --merge  A       A     A
 400                                --keep  (disallowed)
 401
 402X means any state and U means an unmerged index.
 403
 404GIT
 405---
 406Part of the linkgit:git[1] suite