Merge branch 'cb/maint-no-double-merge' into maint
[git] / git-rebase.sh
1 #!/bin/sh
2 #
3 # Copyright (c) 2005 Junio C Hamano.
4 #
5
6 USAGE='[--interactive | -i] [-v] [--force-rebase | -f] [--onto <newbase>] [<upstream>|--root] [<branch>]'
7 LONG_USAGE='git-rebase replaces <branch> with a new branch of the
8 same name.  When the --onto option is provided the new branch starts
9 out with a HEAD equal to <newbase>, otherwise it is equal to <upstream>
10 It then attempts to create a new commit for each commit from the original
11 <branch> that does not exist in the <upstream> branch.
12
13 It is possible that a merge failure will prevent this process from being
14 completely automatic.  You will have to resolve any such merge failure
15 and run git rebase --continue.  Another option is to bypass the commit
16 that caused the merge failure with git rebase --skip.  To restore the
17 original <branch> and remove the .git/rebase-apply working files, use the
18 command git rebase --abort instead.
19
20 Note that if <branch> is not specified on the command line, the
21 currently checked out branch is used.
22
23 Example:       git-rebase master~1 topic
24
25         A---B---C topic                   A'\''--B'\''--C'\'' topic
26        /                   -->           /
27   D---E---F---G master          D---E---F---G master
28 '
29
30 SUBDIRECTORY_OK=Yes
31 OPTIONS_SPEC=
32 . git-sh-setup
33 set_reflog_action rebase
34 require_work_tree
35 cd_to_toplevel
36
37 OK_TO_SKIP_PRE_REBASE=
38 RESOLVEMSG="
39 When you have resolved this problem run \"git rebase --continue\".
40 If you would prefer to skip this patch, instead run \"git rebase --skip\".
41 To restore the original branch and stop rebasing run \"git rebase --abort\".
42 "
43 unset newbase
44 strategy=recursive
45 do_merge=
46 dotest="$GIT_DIR"/rebase-merge
47 prec=4
48 verbose=
49 diffstat=$(git config --bool rebase.stat)
50 git_am_opt=
51 rebase_root=
52 force_rebase=
53
54 continue_merge () {
55         test -n "$prev_head" || die "prev_head must be defined"
56         test -d "$dotest" || die "$dotest directory does not exist"
57
58         unmerged=$(git ls-files -u)
59         if test -n "$unmerged"
60         then
61                 echo "You still have unmerged paths in your index"
62                 echo "did you forget to use git add?"
63                 die "$RESOLVEMSG"
64         fi
65
66         cmt=`cat "$dotest/current"`
67         if ! git diff-index --quiet --ignore-submodules HEAD --
68         then
69                 if ! git commit --no-verify -C "$cmt"
70                 then
71                         echo "Commit failed, please do not call \"git commit\""
72                         echo "directly, but instead do one of the following: "
73                         die "$RESOLVEMSG"
74                 fi
75                 printf "Committed: %0${prec}d " $msgnum
76         else
77                 printf "Already applied: %0${prec}d " $msgnum
78         fi
79         git rev-list --pretty=oneline -1 "$cmt" | sed -e 's/^[^ ]* //'
80
81         prev_head=`git rev-parse HEAD^0`
82         # save the resulting commit so we can read-tree on it later
83         echo "$prev_head" > "$dotest/prev_head"
84
85         # onto the next patch:
86         msgnum=$(($msgnum + 1))
87         echo "$msgnum" >"$dotest/msgnum"
88 }
89
90 call_merge () {
91         cmt="$(cat "$dotest/cmt.$1")"
92         echo "$cmt" > "$dotest/current"
93         hd=$(git rev-parse --verify HEAD)
94         cmt_name=$(git symbolic-ref HEAD 2> /dev/null || echo HEAD)
95         msgnum=$(cat "$dotest/msgnum")
96         end=$(cat "$dotest/end")
97         eval GITHEAD_$cmt='"${cmt_name##refs/heads/}~$(($end - $msgnum))"'
98         eval GITHEAD_$hd='$(cat "$dotest/onto_name")'
99         export GITHEAD_$cmt GITHEAD_$hd
100         git-merge-$strategy "$cmt^" -- "$hd" "$cmt"
101         rv=$?
102         case "$rv" in
103         0)
104                 unset GITHEAD_$cmt GITHEAD_$hd
105                 return
106                 ;;
107         1)
108                 git rerere
109                 die "$RESOLVEMSG"
110                 ;;
111         2)
112                 echo "Strategy: $rv $strategy failed, try another" 1>&2
113                 die "$RESOLVEMSG"
114                 ;;
115         *)
116                 die "Unknown exit code ($rv) from command:" \
117                         "git-merge-$strategy $cmt^ -- HEAD $cmt"
118                 ;;
119         esac
120 }
121
122 move_to_original_branch () {
123         test -z "$head_name" &&
124                 head_name="$(cat "$dotest"/head-name)" &&
125                 onto="$(cat "$dotest"/onto)" &&
126                 orig_head="$(cat "$dotest"/orig-head)"
127         case "$head_name" in
128         refs/*)
129                 message="rebase finished: $head_name onto $onto"
130                 git update-ref -m "$message" \
131                         $head_name $(git rev-parse HEAD) $orig_head &&
132                 git symbolic-ref HEAD $head_name ||
133                 die "Could not move back to $head_name"
134                 ;;
135         esac
136 }
137
138 finish_rb_merge () {
139         move_to_original_branch
140         rm -r "$dotest"
141         echo "All done."
142 }
143
144 is_interactive () {
145         while test $# != 0
146         do
147                 case "$1" in
148                         -i|--interactive)
149                                 interactive_rebase=explicit
150                                 break
151                         ;;
152                         -p|--preserve-merges)
153                                 interactive_rebase=implied
154                         ;;
155                 esac
156                 shift
157         done
158
159         if [ "$interactive_rebase" = implied ]; then
160                 GIT_EDITOR=:
161                 export GIT_EDITOR
162         fi
163
164         test -n "$interactive_rebase" || test -f "$dotest"/interactive
165 }
166
167 run_pre_rebase_hook () {
168         if test -z "$OK_TO_SKIP_PRE_REBASE" &&
169            test -x "$GIT_DIR/hooks/pre-rebase"
170         then
171                 "$GIT_DIR/hooks/pre-rebase" ${1+"$@"} ||
172                 die "The pre-rebase hook refused to rebase."
173         fi
174 }
175
176 test -f "$GIT_DIR"/rebase-apply/applying &&
177         die 'It looks like git-am is in progress. Cannot rebase.'
178
179 is_interactive "$@" && exec git-rebase--interactive "$@"
180
181 if test $# -eq 0
182 then
183         test -d "$dotest" -o -d "$GIT_DIR"/rebase-apply || usage
184         test -d "$dotest" -o -f "$GIT_DIR"/rebase-apply/rebasing &&
185                 die 'A rebase is in progress, try --continue, --skip or --abort.'
186         die "No arguments given and $GIT_DIR/rebase-apply already exists."
187 fi
188
189 while test $# != 0
190 do
191         case "$1" in
192         --no-verify)
193                 OK_TO_SKIP_PRE_REBASE=yes
194                 ;;
195         --continue)
196                 test -d "$dotest" -o -d "$GIT_DIR"/rebase-apply ||
197                         die "No rebase in progress?"
198
199                 git diff-files --quiet --ignore-submodules || {
200                         echo "You must edit all merge conflicts and then"
201                         echo "mark them as resolved using git add"
202                         exit 1
203                 }
204                 if test -d "$dotest"
205                 then
206                         prev_head=$(cat "$dotest/prev_head")
207                         end=$(cat "$dotest/end")
208                         msgnum=$(cat "$dotest/msgnum")
209                         onto=$(cat "$dotest/onto")
210                         continue_merge
211                         while test "$msgnum" -le "$end"
212                         do
213                                 call_merge "$msgnum"
214                                 continue_merge
215                         done
216                         finish_rb_merge
217                         exit
218                 fi
219                 head_name=$(cat "$GIT_DIR"/rebase-apply/head-name) &&
220                 onto=$(cat "$GIT_DIR"/rebase-apply/onto) &&
221                 orig_head=$(cat "$GIT_DIR"/rebase-apply/orig-head) &&
222                 git am --resolved --3way --resolvemsg="$RESOLVEMSG" &&
223                 move_to_original_branch
224                 exit
225                 ;;
226         --skip)
227                 test -d "$dotest" -o -d "$GIT_DIR"/rebase-apply ||
228                         die "No rebase in progress?"
229
230                 git reset --hard HEAD || exit $?
231                 if test -d "$dotest"
232                 then
233                         git rerere clear
234                         prev_head=$(cat "$dotest/prev_head")
235                         end=$(cat "$dotest/end")
236                         msgnum=$(cat "$dotest/msgnum")
237                         msgnum=$(($msgnum + 1))
238                         onto=$(cat "$dotest/onto")
239                         while test "$msgnum" -le "$end"
240                         do
241                                 call_merge "$msgnum"
242                                 continue_merge
243                         done
244                         finish_rb_merge
245                         exit
246                 fi
247                 head_name=$(cat "$GIT_DIR"/rebase-apply/head-name) &&
248                 onto=$(cat "$GIT_DIR"/rebase-apply/onto) &&
249                 orig_head=$(cat "$GIT_DIR"/rebase-apply/orig-head) &&
250                 git am -3 --skip --resolvemsg="$RESOLVEMSG" &&
251                 move_to_original_branch
252                 exit
253                 ;;
254         --abort)
255                 test -d "$dotest" -o -d "$GIT_DIR"/rebase-apply ||
256                         die "No rebase in progress?"
257
258                 git rerere clear
259                 if test -d "$dotest"
260                 then
261                         move_to_original_branch
262                 else
263                         dotest="$GIT_DIR"/rebase-apply
264                         move_to_original_branch
265                 fi
266                 git reset --hard $(cat "$dotest/orig-head")
267                 rm -r "$dotest"
268                 exit
269                 ;;
270         --onto)
271                 test 2 -le "$#" || usage
272                 newbase="$2"
273                 shift
274                 ;;
275         -M|-m|--m|--me|--mer|--merg|--merge)
276                 do_merge=t
277                 ;;
278         -s=*|--s=*|--st=*|--str=*|--stra=*|--strat=*|--strate=*|\
279                 --strateg=*|--strategy=*|\
280         -s|--s|--st|--str|--stra|--strat|--strate|--strateg|--strategy)
281                 case "$#,$1" in
282                 *,*=*)
283                         strategy=`expr "z$1" : 'z-[^=]*=\(.*\)'` ;;
284                 1,*)
285                         usage ;;
286                 *)
287                         strategy="$2"
288                         shift ;;
289                 esac
290                 do_merge=t
291                 ;;
292         -n|--no-stat)
293                 diffstat=
294                 ;;
295         --stat)
296                 diffstat=t
297                 ;;
298         -v|--verbose)
299                 verbose=t
300                 diffstat=t
301                 ;;
302         --whitespace=*)
303                 git_am_opt="$git_am_opt $1"
304                 case "$1" in
305                 --whitespace=fix|--whitespace=strip)
306                         force_rebase=t
307                         ;;
308                 esac
309                 ;;
310         --committer-date-is-author-date|--ignore-date)
311                 git_am_opt="$git_am_opt $1"
312                 force_rebase=t
313                 ;;
314         -C*)
315                 git_am_opt="$git_am_opt $1"
316                 ;;
317         --root)
318                 rebase_root=t
319                 ;;
320         -f|--f|--fo|--for|--forc|force|--force-r|--force-re|--force-reb|--force-reba|--force-rebas|--force-rebase)
321                 force_rebase=t
322                 ;;
323         -*)
324                 usage
325                 ;;
326         *)
327                 break
328                 ;;
329         esac
330         shift
331 done
332 test $# -gt 2 && usage
333
334 # Make sure we do not have $GIT_DIR/rebase-apply
335 if test -z "$do_merge"
336 then
337         if mkdir "$GIT_DIR"/rebase-apply 2>/dev/null
338         then
339                 rmdir "$GIT_DIR"/rebase-apply
340         else
341                 echo >&2 '
342 It seems that I cannot create a rebase-apply directory, and
343 I wonder if you are in the middle of patch application or another
344 rebase.  If that is not the case, please
345         rm -fr '"$GIT_DIR"'/rebase-apply
346 and run me again.  I am stopping in case you still have something
347 valuable there.'
348                 exit 1
349         fi
350 else
351         if test -d "$dotest"
352         then
353                 die "previous rebase directory $dotest still exists." \
354                         'Try git rebase (--continue | --abort | --skip)'
355         fi
356 fi
357
358 # The tree must be really really clean.
359 if ! git update-index --ignore-submodules --refresh; then
360         die "cannot rebase: you have unstaged changes"
361 fi
362 diff=$(git diff-index --cached --name-status -r --ignore-submodules HEAD --)
363 case "$diff" in
364 ?*)     echo >&2 "cannot rebase: your index contains uncommitted changes"
365         echo >&2 "$diff"
366         exit 1
367         ;;
368 esac
369
370 if test -z "$rebase_root"
371 then
372         # The upstream head must be given.  Make sure it is valid.
373         upstream_name="$1"
374         shift
375         upstream=`git rev-parse --verify "${upstream_name}^0"` ||
376         die "invalid upstream $upstream_name"
377         unset root_flag
378         upstream_arg="$upstream_name"
379 else
380         test -z "$newbase" && die "--root must be used with --onto"
381         unset upstream_name
382         unset upstream
383         root_flag="--root"
384         upstream_arg="$root_flag"
385 fi
386
387 # Make sure the branch to rebase onto is valid.
388 onto_name=${newbase-"$upstream_name"}
389 onto=$(git rev-parse --verify "${onto_name}^0") || exit
390
391 # If a hook exists, give it a chance to interrupt
392 run_pre_rebase_hook "$upstream_arg" "$@"
393
394 # If the branch to rebase is given, that is the branch we will rebase
395 # $branch_name -- branch being rebased, or HEAD (already detached)
396 # $orig_head -- commit object name of tip of the branch before rebasing
397 # $head_name -- refs/heads/<that-branch> or "detached HEAD"
398 switch_to=
399 case "$#" in
400 1)
401         # Is it "rebase other $branchname" or "rebase other $commit"?
402         branch_name="$1"
403         switch_to="$1"
404
405         if git show-ref --verify --quiet -- "refs/heads/$1" &&
406            branch=$(git rev-parse -q --verify "refs/heads/$1")
407         then
408                 head_name="refs/heads/$1"
409         elif branch=$(git rev-parse -q --verify "$1")
410         then
411                 head_name="detached HEAD"
412         else
413                 usage
414         fi
415         ;;
416 *)
417         # Do not need to switch branches, we are already on it.
418         if branch_name=`git symbolic-ref -q HEAD`
419         then
420                 head_name=$branch_name
421                 branch_name=`expr "z$branch_name" : 'zrefs/heads/\(.*\)'`
422         else
423                 head_name="detached HEAD"
424                 branch_name=HEAD ;# detached
425         fi
426         branch=$(git rev-parse --verify "${branch_name}^0") || exit
427         ;;
428 esac
429 orig_head=$branch
430
431 # Now we are rebasing commits $upstream..$branch (or with --root,
432 # everything leading up to $branch) on top of $onto
433
434 # Check if we are already based on $onto with linear history,
435 # but this should be done only when upstream and onto are the same.
436 mb=$(git merge-base "$onto" "$branch")
437 if test "$upstream" = "$onto" && test "$mb" = "$onto" &&
438         # linear history?
439         ! (git rev-list --parents "$onto".."$branch" | grep " .* ") > /dev/null
440 then
441         if test -z "$force_rebase"
442         then
443                 # Lazily switch to the target branch if needed...
444                 test -z "$switch_to" || git checkout "$switch_to"
445                 echo >&2 "Current branch $branch_name is up to date."
446                 exit 0
447         else
448                 echo "Current branch $branch_name is up to date, rebase forced."
449         fi
450 fi
451
452 # Detach HEAD and reset the tree
453 echo "First, rewinding head to replay your work on top of it..."
454 git checkout -q "$onto^0" || die "could not detach HEAD"
455 git update-ref ORIG_HEAD $branch
456
457 if test -n "$diffstat"
458 then
459         if test -n "$verbose"
460         then
461                 echo "Changes from $mb to $onto:"
462         fi
463         # We want color (if set), but no pager
464         GIT_PAGER='' git diff --stat --summary "$mb" "$onto"
465 fi
466
467 # If the $onto is a proper descendant of the tip of the branch, then
468 # we just fast forwarded.
469 if test "$mb" = "$branch"
470 then
471         echo >&2 "Fast-forwarded $branch_name to $onto_name."
472         move_to_original_branch
473         exit 0
474 fi
475
476 if test -n "$rebase_root"
477 then
478         revisions="$onto..$orig_head"
479 else
480         revisions="$upstream..$orig_head"
481 fi
482
483 if test -z "$do_merge"
484 then
485         git format-patch -k --stdout --full-index --ignore-if-in-upstream \
486                 $root_flag "$revisions" |
487         git am $git_am_opt --rebasing --resolvemsg="$RESOLVEMSG" &&
488         move_to_original_branch
489         ret=$?
490         test 0 != $ret -a -d "$GIT_DIR"/rebase-apply &&
491                 echo $head_name > "$GIT_DIR"/rebase-apply/head-name &&
492                 echo $onto > "$GIT_DIR"/rebase-apply/onto &&
493                 echo $orig_head > "$GIT_DIR"/rebase-apply/orig-head
494         exit $ret
495 fi
496
497 # start doing a rebase with git-merge
498 # this is rename-aware if the recursive (default) strategy is used
499
500 mkdir -p "$dotest"
501 echo "$onto" > "$dotest/onto"
502 echo "$onto_name" > "$dotest/onto_name"
503 prev_head=$orig_head
504 echo "$prev_head" > "$dotest/prev_head"
505 echo "$orig_head" > "$dotest/orig-head"
506 echo "$head_name" > "$dotest/head-name"
507
508 msgnum=0
509 for cmt in `git rev-list --reverse --no-merges "$revisions"`
510 do
511         msgnum=$(($msgnum + 1))
512         echo "$cmt" > "$dotest/cmt.$msgnum"
513 done
514
515 echo 1 >"$dotest/msgnum"
516 echo $msgnum >"$dotest/end"
517
518 end=$msgnum
519 msgnum=1
520
521 while test "$msgnum" -le "$end"
522 do
523         call_merge "$msgnum"
524         continue_merge
525 done
526
527 finish_rb_merge