rebase: extract am code to new source file
[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] [--no-ff] [--onto <newbase>] (<upstream>|--root) [<branch>] [--quiet | -q]'
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 LF='
38 '
39 ok_to_skip_pre_rebase=
40 resolvemsg="
41 When you have resolved this problem run \"git rebase --continue\".
42 If you would prefer to skip this patch, instead run \"git rebase --skip\".
43 To restore the original branch and stop rebasing run \"git rebase --abort\".
44 "
45 unset onto
46 strategy=
47 strategy_opts=
48 do_merge=
49 merge_dir="$GIT_DIR"/rebase-merge
50 apply_dir="$GIT_DIR"/rebase-apply
51 verbose=
52 diffstat=
53 test "$(git config --bool rebase.stat)" = true && diffstat=t
54 git_am_opt=
55 rebase_root=
56 force_rebase=
57 allow_rerere_autoupdate=
58 # Non-empty if a rebase was in progress when 'git rebase' was invoked
59 in_progress=
60 # One of {am, merge, interactive}
61 type=
62 # One of {"$GIT_DIR"/rebase-apply, "$GIT_DIR"/rebase-merge}
63 state_dir=
64 # One of {'', continue, skip, abort}, as parsed from command line
65 action=
66 preserve_merges=
67 autosquash=
68 test "$(git config --bool rebase.autosquash)" = "true" && autosquash=t
69
70 read_basic_state () {
71         head_name=$(cat "$state_dir"/head-name) &&
72         onto=$(cat "$state_dir"/onto) &&
73         orig_head=$(cat "$state_dir"/orig-head) &&
74         GIT_QUIET=$(cat "$state_dir"/quiet)
75 }
76
77 move_to_original_branch () {
78         case "$head_name" in
79         refs/*)
80                 message="rebase finished: $head_name onto $onto"
81                 git update-ref -m "$message" \
82                         $head_name $(git rev-parse HEAD) $orig_head &&
83                 git symbolic-ref HEAD $head_name ||
84                 die "Could not move back to $head_name"
85                 ;;
86         esac
87 }
88
89 run_specific_rebase () {
90         if [ "$interactive_rebase" = implied ]; then
91                 GIT_EDITOR=:
92                 export GIT_EDITOR
93         fi
94         . git-rebase--$type
95 }
96
97 run_pre_rebase_hook () {
98         if test -z "$ok_to_skip_pre_rebase" &&
99            test -x "$GIT_DIR/hooks/pre-rebase"
100         then
101                 "$GIT_DIR/hooks/pre-rebase" ${1+"$@"} ||
102                 die "The pre-rebase hook refused to rebase."
103         fi
104 }
105
106 test -f "$apply_dir"/applying &&
107         die 'It looks like git-am is in progress. Cannot rebase.'
108
109 if test -d "$apply_dir"
110 then
111         type=am
112         state_dir="$apply_dir"
113 elif test -d "$merge_dir"
114 then
115         if test -f "$merge_dir"/interactive
116         then
117                 type=interactive
118                 interactive_rebase=explicit
119         else
120                 type=merge
121         fi
122         state_dir="$merge_dir"
123 fi
124 test -n "$type" && in_progress=t
125
126 total_argc=$#
127 while test $# != 0
128 do
129         case "$1" in
130         --no-verify)
131                 ok_to_skip_pre_rebase=yes
132                 ;;
133         --verify)
134                 ok_to_skip_pre_rebase=
135                 ;;
136         --continue|--skip|--abort)
137                 test $total_argc -eq 1 || usage
138                 action=${1##--}
139                 ;;
140         --onto)
141                 test 2 -le "$#" || usage
142                 onto="$2"
143                 shift
144                 ;;
145         -i|--interactive)
146                 interactive_rebase=explicit
147                 ;;
148         -p|--preserve-merges)
149                 preserve_merges=t
150                 test -z "$interactive_rebase" && interactive_rebase=implied
151                 ;;
152         --autosquash)
153                 autosquash=t
154                 ;;
155         --no-autosquash)
156                 autosquash=
157                 ;;
158         -M|-m|--m|--me|--mer|--merg|--merge)
159                 do_merge=t
160                 ;;
161         -X*|--strategy-option*)
162                 case "$#,$1" in
163                 1,-X|1,--strategy-option)
164                         usage ;;
165                 *,-X|*,--strategy-option)
166                         newopt="$2"
167                         shift ;;
168                 *,--strategy-option=*)
169                         newopt="$(expr " $1" : ' --strategy-option=\(.*\)')" ;;
170                 *,-X*)
171                         newopt="$(expr " $1" : ' -X\(.*\)')" ;;
172                 1,*)
173                         usage ;;
174                 esac
175                 strategy_opts="$strategy_opts $(git rev-parse --sq-quote "--$newopt")"
176                 do_merge=t
177                 test -z "$strategy" && strategy=recursive
178                 ;;
179         -s=*|--s=*|--st=*|--str=*|--stra=*|--strat=*|--strate=*|\
180                 --strateg=*|--strategy=*|\
181         -s|--s|--st|--str|--stra|--strat|--strate|--strateg|--strategy)
182                 case "$#,$1" in
183                 *,*=*)
184                         strategy=`expr "z$1" : 'z-[^=]*=\(.*\)'` ;;
185                 1,*)
186                         usage ;;
187                 *)
188                         strategy="$2"
189                         shift ;;
190                 esac
191                 do_merge=t
192                 ;;
193         -n|--no-stat)
194                 diffstat=
195                 ;;
196         --stat)
197                 diffstat=t
198                 ;;
199         -v|--verbose)
200                 verbose=t
201                 diffstat=t
202                 GIT_QUIET=
203                 ;;
204         -q|--quiet)
205                 GIT_QUIET=t
206                 git_am_opt="$git_am_opt -q"
207                 verbose=
208                 diffstat=
209                 ;;
210         --whitespace=*)
211                 git_am_opt="$git_am_opt $1"
212                 case "$1" in
213                 --whitespace=fix|--whitespace=strip)
214                         force_rebase=t
215                         ;;
216                 esac
217                 ;;
218         --ignore-whitespace)
219                 git_am_opt="$git_am_opt $1"
220                 ;;
221         --committer-date-is-author-date|--ignore-date)
222                 git_am_opt="$git_am_opt $1"
223                 force_rebase=t
224                 ;;
225         -C*)
226                 git_am_opt="$git_am_opt $1"
227                 ;;
228         --root)
229                 rebase_root=t
230                 ;;
231         -f|--f|--fo|--for|--forc|--force|--force-r|--force-re|--force-reb|--force-reba|--force-rebas|--force-rebase|--no-ff)
232                 force_rebase=t
233                 ;;
234         --rerere-autoupdate|--no-rerere-autoupdate)
235                 allow_rerere_autoupdate="$1"
236                 ;;
237         -*)
238                 usage
239                 ;;
240         *)
241                 break
242                 ;;
243         esac
244         shift
245 done
246 test $# -gt 2 && usage
247
248 if test -n "$action"
249 then
250         test -z "$in_progress" && die "No rebase in progress?"
251         test "$type" = interactive && run_specific_rebase
252 fi
253
254 case "$action" in
255 continue)
256         git update-index --ignore-submodules --refresh &&
257         git diff-files --quiet --ignore-submodules || {
258                 echo "You must edit all merge conflicts and then"
259                 echo "mark them as resolved using git add"
260                 exit 1
261         }
262         read_basic_state
263         run_specific_rebase
264         ;;
265 skip)
266         git reset --hard HEAD || exit $?
267         read_basic_state
268         run_specific_rebase
269         ;;
270 abort)
271         git rerere clear
272         read_basic_state
273         case "$head_name" in
274         refs/*)
275                 git symbolic-ref HEAD $head_name ||
276                 die "Could not move back to $head_name"
277                 ;;
278         esac
279         git reset --hard $orig_head
280         rm -r "$state_dir"
281         exit
282         ;;
283 esac
284
285 # Make sure no rebase is in progress
286 if test -n "$in_progress"
287 then
288         die '
289 It seems that there is already a '"${state_dir##*/}"' directory, and
290 I wonder if you are in the middle of another rebase.  If that is the
291 case, please try
292         git rebase (--continue | --abort | --skip)
293 If that is not the case, please
294         rm -fr '"$state_dir"'
295 and run me again.  I am stopping in case you still have something
296 valuable there.'
297 fi
298
299 test $# -eq 0 && test -z "$rebase_root" && usage
300
301 if test -n "$interactive_rebase"
302 then
303         type=interactive
304         state_dir="$merge_dir"
305 elif test -n "$do_merge"
306 then
307         type=merge
308         state_dir="$merge_dir"
309 else
310         type=am
311         state_dir="$apply_dir"
312 fi
313
314 if test -z "$rebase_root"
315 then
316         # The upstream head must be given.  Make sure it is valid.
317         upstream_name="$1"
318         shift
319         upstream=`git rev-parse --verify "${upstream_name}^0"` ||
320         die "invalid upstream $upstream_name"
321         upstream_arg="$upstream_name"
322 else
323         test -z "$onto" && die "You must specify --onto when using --root"
324         unset upstream_name
325         unset upstream
326         upstream_arg=--root
327 fi
328
329 # Make sure the branch to rebase onto is valid.
330 onto_name=${onto-"$upstream_name"}
331 case "$onto_name" in
332 *...*)
333         if      left=${onto_name%...*} right=${onto_name#*...} &&
334                 onto=$(git merge-base --all ${left:-HEAD} ${right:-HEAD})
335         then
336                 case "$onto" in
337                 ?*"$LF"?*)
338                         die "$onto_name: there are more than one merge bases"
339                         ;;
340                 '')
341                         die "$onto_name: there is no merge base"
342                         ;;
343                 esac
344         else
345                 die "$onto_name: there is no merge base"
346         fi
347         ;;
348 *)
349         onto=$(git rev-parse --verify "${onto_name}^0") ||
350         die "Does not point to a valid commit: $1"
351         ;;
352 esac
353
354 # If the branch to rebase is given, that is the branch we will rebase
355 # $branch_name -- branch being rebased, or HEAD (already detached)
356 # $orig_head -- commit object name of tip of the branch before rebasing
357 # $head_name -- refs/heads/<that-branch> or "detached HEAD"
358 switch_to=
359 case "$#" in
360 1)
361         # Is it "rebase other $branchname" or "rebase other $commit"?
362         branch_name="$1"
363         switch_to="$1"
364
365         if git show-ref --verify --quiet -- "refs/heads/$1" &&
366            orig_head=$(git rev-parse -q --verify "refs/heads/$1")
367         then
368                 head_name="refs/heads/$1"
369         elif orig_head=$(git rev-parse -q --verify "$1")
370         then
371                 head_name="detached HEAD"
372         else
373                 echo >&2 "fatal: no such branch: $1"
374                 usage
375         fi
376         ;;
377 *)
378         # Do not need to switch branches, we are already on it.
379         if branch_name=`git symbolic-ref -q HEAD`
380         then
381                 head_name=$branch_name
382                 branch_name=`expr "z$branch_name" : 'zrefs/heads/\(.*\)'`
383         else
384                 head_name="detached HEAD"
385                 branch_name=HEAD ;# detached
386         fi
387         orig_head=$(git rev-parse --verify "${branch_name}^0") || exit
388         ;;
389 esac
390
391 require_clean_work_tree "rebase" "Please commit or stash them."
392
393 # Now we are rebasing commits $upstream..$orig_head (or with --root,
394 # everything leading up to $orig_head) on top of $onto
395
396 # Check if we are already based on $onto with linear history,
397 # but this should be done only when upstream and onto are the same
398 # and if this is not an interactive rebase.
399 mb=$(git merge-base "$onto" "$orig_head")
400 if test "$type" != interactive && test "$upstream" = "$onto" &&
401         test "$mb" = "$onto" &&
402         # linear history?
403         ! (git rev-list --parents "$onto".."$orig_head" | sane_grep " .* ") > /dev/null
404 then
405         if test -z "$force_rebase"
406         then
407                 # Lazily switch to the target branch if needed...
408                 test -z "$switch_to" || git checkout "$switch_to" --
409                 say "Current branch $branch_name is up to date."
410                 exit 0
411         else
412                 say "Current branch $branch_name is up to date, rebase forced."
413         fi
414 fi
415
416 # If a hook exists, give it a chance to interrupt
417 run_pre_rebase_hook "$upstream_arg" "$@"
418
419 if test -n "$diffstat"
420 then
421         if test -n "$verbose"
422         then
423                 echo "Changes from $mb to $onto:"
424         fi
425         # We want color (if set), but no pager
426         GIT_PAGER='' git diff --stat --summary "$mb" "$onto"
427 fi
428
429 test "$type" = interactive && run_specific_rebase
430
431 # Detach HEAD and reset the tree
432 say "First, rewinding head to replay your work on top of it..."
433 git checkout -q "$onto^0" || die "could not detach HEAD"
434 git update-ref ORIG_HEAD $orig_head
435
436 # If the $onto is a proper descendant of the tip of the branch, then
437 # we just fast-forwarded.
438 if test "$mb" = "$orig_head"
439 then
440         say "Fast-forwarded $branch_name to $onto_name."
441         move_to_original_branch
442         exit 0
443 fi
444
445 if test -n "$rebase_root"
446 then
447         revisions="$onto..$orig_head"
448 else
449         revisions="$upstream..$orig_head"
450 fi
451
452 run_specific_rebase