builtin-name-rev.c: split deeply nested part from the main function
[git] / git-rebase.sh
1 #!/bin/sh
2 #
3 # Copyright (c) 2005 Junio C Hamano.
4 #
5
6 USAGE='[--interactive | -i] [-v] [--onto <newbase>] <upstream> [<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 .dotest working files, use the command
18 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 RESOLVEMSG="
38 When you have resolved this problem run \"git rebase --continue\".
39 If you would prefer to skip this patch, instead run \"git rebase --skip\".
40 To restore the original branch and stop rebasing run \"git rebase --abort\".
41 "
42 unset newbase
43 strategy=recursive
44 do_merge=
45 dotest=$GIT_DIR/.dotest-merge
46 prec=4
47 verbose=
48 git_am_opt=
49
50 continue_merge () {
51         test -n "$prev_head" || die "prev_head must be defined"
52         test -d "$dotest" || die "$dotest directory does not exist"
53
54         unmerged=$(git ls-files -u)
55         if test -n "$unmerged"
56         then
57                 echo "You still have unmerged paths in your index"
58                 echo "did you forget to use git add?"
59                 die "$RESOLVEMSG"
60         fi
61
62         cmt=`cat "$dotest/current"`
63         if ! git diff-index --quiet --ignore-submodules HEAD --
64         then
65                 if ! git commit --no-verify -C "$cmt"
66                 then
67                         echo "Commit failed, please do not call \"git commit\""
68                         echo "directly, but instead do one of the following: "
69                         die "$RESOLVEMSG"
70                 fi
71                 printf "Committed: %0${prec}d " $msgnum
72         else
73                 printf "Already applied: %0${prec}d " $msgnum
74         fi
75         git rev-list --pretty=oneline -1 "$cmt" | sed -e 's/^[^ ]* //'
76
77         prev_head=`git rev-parse HEAD^0`
78         # save the resulting commit so we can read-tree on it later
79         echo "$prev_head" > "$dotest/prev_head"
80
81         # onto the next patch:
82         msgnum=$(($msgnum + 1))
83         echo "$msgnum" >"$dotest/msgnum"
84 }
85
86 call_merge () {
87         cmt="$(cat "$dotest/cmt.$1")"
88         echo "$cmt" > "$dotest/current"
89         hd=$(git rev-parse --verify HEAD)
90         cmt_name=$(git symbolic-ref HEAD 2> /dev/null || echo HEAD)
91         msgnum=$(cat "$dotest/msgnum")
92         end=$(cat "$dotest/end")
93         eval GITHEAD_$cmt='"${cmt_name##refs/heads/}~$(($end - $msgnum))"'
94         eval GITHEAD_$hd='$(cat "$dotest/onto_name")'
95         export GITHEAD_$cmt GITHEAD_$hd
96         git-merge-$strategy "$cmt^" -- "$hd" "$cmt"
97         rv=$?
98         case "$rv" in
99         0)
100                 unset GITHEAD_$cmt GITHEAD_$hd
101                 return
102                 ;;
103         1)
104                 git rerere
105                 die "$RESOLVEMSG"
106                 ;;
107         2)
108                 echo "Strategy: $rv $strategy failed, try another" 1>&2
109                 die "$RESOLVEMSG"
110                 ;;
111         *)
112                 die "Unknown exit code ($rv) from command:" \
113                         "git-merge-$strategy $cmt^ -- HEAD $cmt"
114                 ;;
115         esac
116 }
117
118 move_to_original_branch () {
119         test -z "$head_name" &&
120                 head_name="$(cat "$dotest"/head-name)" &&
121                 onto="$(cat "$dotest"/onto)" &&
122                 orig_head="$(cat "$dotest"/orig-head)"
123         case "$head_name" in
124         refs/*)
125                 message="rebase finished: $head_name onto $onto"
126                 git update-ref -m "$message" \
127                         $head_name $(git rev-parse HEAD) $orig_head &&
128                 git symbolic-ref HEAD $head_name ||
129                 die "Could not move back to $head_name"
130                 ;;
131         esac
132 }
133
134 finish_rb_merge () {
135         move_to_original_branch
136         rm -r "$dotest"
137         echo "All done."
138 }
139
140 is_interactive () {
141         test -f "$dotest"/interactive ||
142         while :; do case $#,"$1" in 0,|*,-i|*,--interactive) break ;; esac
143                 shift
144         done && test -n "$1"
145 }
146
147 is_interactive "$@" && exec git-rebase--interactive "$@"
148
149 while test $# != 0
150 do
151         case "$1" in
152         --continue)
153                 test -d "$dotest" -o -d .dotest ||
154                         die "No rebase in progress?"
155
156                 git diff-files --quiet --ignore-submodules || {
157                         echo "You must edit all merge conflicts and then"
158                         echo "mark them as resolved using git add"
159                         exit 1
160                 }
161                 if test -d "$dotest"
162                 then
163                         prev_head=$(cat "$dotest/prev_head")
164                         end=$(cat "$dotest/end")
165                         msgnum=$(cat "$dotest/msgnum")
166                         onto=$(cat "$dotest/onto")
167                         continue_merge
168                         while test "$msgnum" -le "$end"
169                         do
170                                 call_merge "$msgnum"
171                                 continue_merge
172                         done
173                         finish_rb_merge
174                         exit
175                 fi
176                 head_name=$(cat .dotest/head-name) &&
177                 onto=$(cat .dotest/onto) &&
178                 orig_head=$(cat .dotest/orig-head) &&
179                 git am --resolved --3way --resolvemsg="$RESOLVEMSG" &&
180                 move_to_original_branch
181                 exit
182                 ;;
183         --skip)
184                 test -d "$dotest" -o -d .dotest ||
185                         die "No rebase in progress?"
186
187                 git reset --hard HEAD || exit $?
188                 if test -d "$dotest"
189                 then
190                         git rerere clear
191                         prev_head=$(cat "$dotest/prev_head")
192                         end=$(cat "$dotest/end")
193                         msgnum=$(cat "$dotest/msgnum")
194                         msgnum=$(($msgnum + 1))
195                         onto=$(cat "$dotest/onto")
196                         while test "$msgnum" -le "$end"
197                         do
198                                 call_merge "$msgnum"
199                                 continue_merge
200                         done
201                         finish_rb_merge
202                         exit
203                 fi
204                 head_name=$(cat .dotest/head-name) &&
205                 onto=$(cat .dotest/onto) &&
206                 orig_head=$(cat .dotest/orig-head) &&
207                 git am -3 --skip --resolvemsg="$RESOLVEMSG" &&
208                 move_to_original_branch
209                 exit
210                 ;;
211         --abort)
212                 test -d "$dotest" -o -d .dotest ||
213                         die "No rebase in progress?"
214
215                 git rerere clear
216                 if test -d "$dotest"
217                 then
218                         move_to_original_branch
219                 else
220                         dotest=.dotest
221                         move_to_original_branch
222                 fi
223                 git reset --hard $(cat "$dotest/orig-head")
224                 rm -r "$dotest"
225                 exit
226                 ;;
227         --onto)
228                 test 2 -le "$#" || usage
229                 newbase="$2"
230                 shift
231                 ;;
232         -M|-m|--m|--me|--mer|--merg|--merge)
233                 do_merge=t
234                 ;;
235         -s=*|--s=*|--st=*|--str=*|--stra=*|--strat=*|--strate=*|\
236                 --strateg=*|--strategy=*|\
237         -s|--s|--st|--str|--stra|--strat|--strate|--strateg|--strategy)
238                 case "$#,$1" in
239                 *,*=*)
240                         strategy=`expr "z$1" : 'z-[^=]*=\(.*\)'` ;;
241                 1,*)
242                         usage ;;
243                 *)
244                         strategy="$2"
245                         shift ;;
246                 esac
247                 do_merge=t
248                 ;;
249         -v|--verbose)
250                 verbose=t
251                 ;;
252         --whitespace=*)
253                 git_am_opt="$git_am_opt $1"
254                 ;;
255         -C*)
256                 git_am_opt="$git_am_opt $1"
257                 ;;
258         -*)
259                 usage
260                 ;;
261         *)
262                 break
263                 ;;
264         esac
265         shift
266 done
267
268 # Make sure we do not have .dotest
269 if test -z "$do_merge"
270 then
271         if mkdir .dotest
272         then
273                 rmdir .dotest
274         else
275                 echo >&2 '
276 It seems that I cannot create a .dotest directory, and I wonder if you
277 are in the middle of patch application or another rebase.  If that is not
278 the case, please rm -fr .dotest and run me again.  I am stopping in case
279 you still have something valuable there.'
280                 exit 1
281         fi
282 else
283         if test -d "$dotest"
284         then
285                 die "previous dotest directory $dotest still exists." \
286                         'try git-rebase < --continue | --abort >'
287         fi
288 fi
289
290 # The tree must be really really clean.
291 git update-index --ignore-submodules --refresh || exit
292 diff=$(git diff-index --cached --name-status -r --ignore-submodules HEAD --)
293 case "$diff" in
294 ?*)     echo "cannot rebase: your index is not up-to-date"
295         echo "$diff"
296         exit 1
297         ;;
298 esac
299
300 # The upstream head must be given.  Make sure it is valid.
301 upstream_name="$1"
302 upstream=`git rev-parse --verify "${upstream_name}^0"` ||
303     die "invalid upstream $upstream_name"
304
305 # Make sure the branch to rebase onto is valid.
306 onto_name=${newbase-"$upstream_name"}
307 onto=$(git rev-parse --verify "${onto_name}^0") || exit
308
309 # If a hook exists, give it a chance to interrupt
310 if test -x "$GIT_DIR/hooks/pre-rebase"
311 then
312         "$GIT_DIR/hooks/pre-rebase" ${1+"$@"} || {
313                 echo >&2 "The pre-rebase hook refused to rebase."
314                 exit 1
315         }
316 fi
317
318 # If the branch to rebase is given, that is the branch we will rebase
319 # $branch_name -- branch being rebased, or HEAD (already detached)
320 # $orig_head -- commit object name of tip of the branch before rebasing
321 # $head_name -- refs/heads/<that-branch> or "detached HEAD"
322 switch_to=
323 case "$#" in
324 2)
325         # Is it "rebase other $branchname" or "rebase other $commit"?
326         branch_name="$2"
327         switch_to="$2"
328
329         if git show-ref --verify --quiet -- "refs/heads/$2" &&
330            branch=$(git rev-parse --verify "refs/heads/$2" 2>/dev/null)
331         then
332                 head_name="refs/heads/$2"
333         elif branch=$(git rev-parse --verify "$2" 2>/dev/null)
334         then
335                 head_name="detached HEAD"
336         else
337                 usage
338         fi
339         ;;
340 *)
341         # Do not need to switch branches, we are already on it.
342         if branch_name=`git symbolic-ref -q HEAD`
343         then
344                 head_name=$branch_name
345                 branch_name=`expr "z$branch_name" : 'zrefs/heads/\(.*\)'`
346         else
347                 head_name="detached HEAD"
348                 branch_name=HEAD ;# detached
349         fi
350         branch=$(git rev-parse --verify "${branch_name}^0") || exit
351         ;;
352 esac
353 orig_head=$branch
354
355 # Now we are rebasing commits $upstream..$branch on top of $onto
356
357 # Check if we are already based on $onto with linear history,
358 # but this should be done only when upstream and onto are the same.
359 mb=$(git merge-base "$onto" "$branch")
360 if test "$upstream" = "$onto" && test "$mb" = "$onto" &&
361         # linear history?
362         ! (git rev-list --parents "$onto".."$branch" | grep " .* ") > /dev/null
363 then
364         # Lazily switch to the target branch if needed...
365         test -z "$switch_to" || git checkout "$switch_to"
366         echo >&2 "Current branch $branch_name is up to date."
367         exit 0
368 fi
369
370 if test -n "$verbose"
371 then
372         echo "Changes from $mb to $onto:"
373         # We want color (if set), but no pager
374         GIT_PAGER='' git diff --stat --summary "$mb" "$onto"
375 fi
376
377 # Detach HEAD and reset the tree
378 echo "First, rewinding head to replay your work on top of it..."
379 git checkout "$onto^0" >/dev/null 2>&1 ||
380         die "could not detach HEAD"
381 # git reset --hard "$onto^0"
382
383 # If the $onto is a proper descendant of the tip of the branch, then
384 # we just fast forwarded.
385 if test "$mb" = "$branch"
386 then
387         echo >&2 "Fast-forwarded $branch_name to $onto_name."
388         move_to_original_branch
389         exit 0
390 fi
391
392 if test -z "$do_merge"
393 then
394         git format-patch -k --stdout --full-index --ignore-if-in-upstream \
395                 "$upstream..$orig_head" |
396         git am $git_am_opt --rebasing --resolvemsg="$RESOLVEMSG" &&
397         move_to_original_branch
398         ret=$?
399         test 0 != $ret -a -d .dotest &&
400                 echo $head_name > .dotest/head-name &&
401                 echo $onto > .dotest/onto &&
402                 echo $orig_head > .dotest/orig-head
403         exit $ret
404 fi
405
406 # start doing a rebase with git-merge
407 # this is rename-aware if the recursive (default) strategy is used
408
409 mkdir -p "$dotest"
410 echo "$onto" > "$dotest/onto"
411 echo "$onto_name" > "$dotest/onto_name"
412 prev_head=$orig_head
413 echo "$prev_head" > "$dotest/prev_head"
414 echo "$orig_head" > "$dotest/orig-head"
415 echo "$head_name" > "$dotest/head-name"
416
417 msgnum=0
418 for cmt in `git rev-list --reverse --no-merges "$upstream..$orig_head"`
419 do
420         msgnum=$(($msgnum + 1))
421         echo "$cmt" > "$dotest/cmt.$msgnum"
422 done
423
424 echo 1 >"$dotest/msgnum"
425 echo $msgnum >"$dotest/end"
426
427 end=$msgnum
428 msgnum=1
429
430 while test "$msgnum" -le "$end"
431 do
432         call_merge "$msgnum"
433         continue_merge
434 done
435
436 finish_rb_merge