Update documentation for update hook.
[git] / git-rebase.sh
1 #!/bin/sh
2 #
3 # Copyright (c) 2005 Junio C Hamano.
4 #
5
6 USAGE='[-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.  You must be in the top
22 directory of your project to start (or continue) a rebase.
23
24 Example:       git-rebase master~1 topic
25
26         A---B---C topic                   A'\''--B'\''--C'\'' topic
27        /                   -->           /
28   D---E---F---G master          D---E---F---G master
29 '
30 . git-sh-setup
31 set_reflog_action rebase
32
33 RESOLVEMSG="
34 When you have resolved this problem run \"git rebase --continue\".
35 If you would prefer to skip this patch, instead run \"git rebase --skip\".
36 To restore the original branch and stop rebasing run \"git rebase --abort\".
37 "
38 unset newbase
39 strategy=recursive
40 do_merge=
41 dotest=$GIT_DIR/.dotest-merge
42 prec=4
43 verbose=
44
45 continue_merge () {
46         test -n "$prev_head" || die "prev_head must be defined"
47         test -d "$dotest" || die "$dotest directory does not exist"
48
49         unmerged=$(git-ls-files -u)
50         if test -n "$unmerged"
51         then
52                 echo "You still have unmerged paths in your index"
53                 echo "did you forget update-index?"
54                 die "$RESOLVEMSG"
55         fi
56
57         if test -n "`git-diff-index HEAD`"
58         then
59                 if ! git-commit -C "`cat $dotest/current`"
60                 then
61                         echo "Commit failed, please do not call \"git commit\""
62                         echo "directly, but instead do one of the following: "
63                         die "$RESOLVEMSG"
64                 fi
65                 printf "Committed: %0${prec}d" $msgnum
66         else
67                 printf "Already applied: %0${prec}d" $msgnum
68         fi
69         echo ' '`git-rev-list --pretty=oneline -1 HEAD | \
70                                 sed 's/^[a-f0-9]\+ //'`
71
72         prev_head=`git-rev-parse HEAD^0`
73         # save the resulting commit so we can read-tree on it later
74         echo "$prev_head" > "$dotest/prev_head"
75
76         # onto the next patch:
77         msgnum=$(($msgnum + 1))
78         echo "$msgnum" >"$dotest/msgnum"
79 }
80
81 call_merge () {
82         cmt="$(cat $dotest/cmt.$1)"
83         echo "$cmt" > "$dotest/current"
84         hd=$(git-rev-parse --verify HEAD)
85         cmt_name=$(git-symbolic-ref HEAD)
86         msgnum=$(cat $dotest/msgnum)
87         end=$(cat $dotest/end)
88         eval GITHEAD_$cmt='"${cmt_name##refs/heads/}~$(($end - $msgnum))"'
89         eval GITHEAD_$hd='"$(cat $dotest/onto_name)"'
90         export GITHEAD_$cmt GITHEAD_$hd
91         git-merge-$strategy "$cmt^" -- "$hd" "$cmt"
92         rv=$?
93         case "$rv" in
94         0)
95                 unset GITHEAD_$cmt GITHEAD_$hd
96                 return
97                 ;;
98         1)
99                 test -d "$GIT_DIR/rr-cache" && git-rerere
100                 die "$RESOLVEMSG"
101                 ;;
102         2)
103                 echo "Strategy: $rv $strategy failed, try another" 1>&2
104                 die "$RESOLVEMSG"
105                 ;;
106         *)
107                 die "Unknown exit code ($rv) from command:" \
108                         "git-merge-$strategy $cmt^ -- HEAD $cmt"
109                 ;;
110         esac
111 }
112
113 finish_rb_merge () {
114         rm -r "$dotest"
115         echo "All done."
116 }
117
118 while case "$#" in 0) break ;; esac
119 do
120         case "$1" in
121         --continue)
122                 diff=$(git-diff-files)
123                 case "$diff" in
124                 ?*)     echo "You must edit all merge conflicts and then"
125                         echo "mark them as resolved using git update-index"
126                         exit 1
127                         ;;
128                 esac
129                 if test -d "$dotest"
130                 then
131                         prev_head="`cat $dotest/prev_head`"
132                         end="`cat $dotest/end`"
133                         msgnum="`cat $dotest/msgnum`"
134                         onto="`cat $dotest/onto`"
135                         continue_merge
136                         while test "$msgnum" -le "$end"
137                         do
138                                 call_merge "$msgnum"
139                                 continue_merge
140                         done
141                         finish_rb_merge
142                         exit
143                 fi
144                 git am --resolved --3way --resolvemsg="$RESOLVEMSG"
145                 exit
146                 ;;
147         --skip)
148                 if test -d "$dotest"
149                 then
150                         if test -d "$GIT_DIR/rr-cache"
151                         then
152                                 git-rerere clear
153                         fi
154                         prev_head="`cat $dotest/prev_head`"
155                         end="`cat $dotest/end`"
156                         msgnum="`cat $dotest/msgnum`"
157                         msgnum=$(($msgnum + 1))
158                         onto="`cat $dotest/onto`"
159                         while test "$msgnum" -le "$end"
160                         do
161                                 call_merge "$msgnum"
162                                 continue_merge
163                         done
164                         finish_rb_merge
165                         exit
166                 fi
167                 git am -3 --skip --resolvemsg="$RESOLVEMSG"
168                 exit
169                 ;;
170         --abort)
171                 if test -d "$GIT_DIR/rr-cache"
172                 then
173                         git-rerere clear
174                 fi
175                 if test -d "$dotest"
176                 then
177                         rm -r "$dotest"
178                 elif test -d .dotest
179                 then
180                         rm -r .dotest
181                 else
182                         die "No rebase in progress?"
183                 fi
184                 git reset --hard ORIG_HEAD
185                 exit
186                 ;;
187         --onto)
188                 test 2 -le "$#" || usage
189                 newbase="$2"
190                 shift
191                 ;;
192         -M|-m|--m|--me|--mer|--merg|--merge)
193                 do_merge=t
194                 ;;
195         -s=*|--s=*|--st=*|--str=*|--stra=*|--strat=*|--strate=*|\
196                 --strateg=*|--strategy=*|\
197         -s|--s|--st|--str|--stra|--strat|--strate|--strateg|--strategy)
198                 case "$#,$1" in
199                 *,*=*)
200                         strategy=`expr "z$1" : 'z-[^=]*=\(.*\)'` ;;
201                 1,*)
202                         usage ;;
203                 *)
204                         strategy="$2"
205                         shift ;;
206                 esac
207                 do_merge=t
208                 ;;
209         -v|--verbose)
210                 verbose=t
211                 ;;
212         -*)
213                 usage
214                 ;;
215         *)
216                 break
217                 ;;
218         esac
219         shift
220 done
221
222 # Make sure we do not have .dotest
223 if test -z "$do_merge"
224 then
225         if mkdir .dotest
226         then
227                 rmdir .dotest
228         else
229                 echo >&2 '
230 It seems that I cannot create a .dotest directory, and I wonder if you
231 are in the middle of patch application or another rebase.  If that is not
232 the case, please rm -fr .dotest and run me again.  I am stopping in case
233 you still have something valuable there.'
234                 exit 1
235         fi
236 else
237         if test -d "$dotest"
238         then
239                 die "previous dotest directory $dotest still exists." \
240                         'try git-rebase < --continue | --abort >'
241         fi
242 fi
243
244 # The tree must be really really clean.
245 git-update-index --refresh || exit
246 diff=$(git-diff-index --cached --name-status -r HEAD)
247 case "$diff" in
248 ?*)     echo "$diff"
249         exit 1
250         ;;
251 esac
252
253 # The upstream head must be given.  Make sure it is valid.
254 upstream_name="$1"
255 upstream=`git rev-parse --verify "${upstream_name}^0"` ||
256     die "invalid upstream $upstream_name"
257
258 # If a hook exists, give it a chance to interrupt
259 if test -x "$GIT_DIR/hooks/pre-rebase"
260 then
261         "$GIT_DIR/hooks/pre-rebase" ${1+"$@"} || {
262                 echo >&2 "The pre-rebase hook refused to rebase."
263                 exit 1
264         }
265 fi
266
267 # If the branch to rebase is given, first switch to it.
268 case "$#" in
269 2)
270         branch_name="$2"
271         git-checkout "$2" || usage
272         ;;
273 *)
274         branch_name=`git symbolic-ref HEAD` || die "No current branch"
275         branch_name=`expr "z$branch_name" : 'zrefs/heads/\(.*\)'`
276         ;;
277 esac
278 branch=$(git-rev-parse --verify "${branch_name}^0") || exit
279
280 # Make sure the branch to rebase onto is valid.
281 onto_name=${newbase-"$upstream_name"}
282 onto=$(git-rev-parse --verify "${onto_name}^0") || exit
283
284 # Now we are rebasing commits $upstream..$branch on top of $onto
285
286 # Check if we are already based on $onto, but this should be
287 # done only when upstream and onto are the same.
288 mb=$(git-merge-base "$onto" "$branch")
289 if test "$upstream" = "$onto" && test "$mb" = "$onto"
290 then
291         echo >&2 "Current branch $branch_name is up to date."
292         exit 0
293 fi
294
295 if test -n "$verbose"
296 then
297         echo "Changes from $mb to $onto:"
298         git-diff-tree --stat --summary "$mb" "$onto"
299 fi
300
301 # Rewind the head to "$onto"; this saves our current head in ORIG_HEAD.
302 echo "First, rewinding head to replay your work on top of it..."
303 git-reset --hard "$onto"
304
305 # If the $onto is a proper descendant of the tip of the branch, then
306 # we just fast forwarded.
307 if test "$mb" = "$branch"
308 then
309         echo >&2 "Fast-forwarded $branch_name to $onto_name."
310         exit 0
311 fi
312
313 if test -z "$do_merge"
314 then
315         git-format-patch -k --stdout --full-index --ignore-if-in-upstream "$upstream"..ORIG_HEAD |
316         git am --binary -3 -k --resolvemsg="$RESOLVEMSG"
317         exit $?
318 fi
319
320 # start doing a rebase with git-merge
321 # this is rename-aware if the recursive (default) strategy is used
322
323 mkdir -p "$dotest"
324 echo "$onto" > "$dotest/onto"
325 echo "$onto_name" > "$dotest/onto_name"
326 prev_head=`git-rev-parse HEAD^0`
327 echo "$prev_head" > "$dotest/prev_head"
328
329 msgnum=0
330 for cmt in `git-rev-list --no-merges "$upstream"..ORIG_HEAD \
331                         | @@PERL@@ -e 'print reverse <>'`
332 do
333         msgnum=$(($msgnum + 1))
334         echo "$cmt" > "$dotest/cmt.$msgnum"
335 done
336
337 echo 1 >"$dotest/msgnum"
338 echo $msgnum >"$dotest/end"
339
340 end=$msgnum
341 msgnum=1
342
343 while test "$msgnum" -le "$end"
344 do
345         call_merge "$msgnum"
346         continue_merge
347 done
348
349 finish_rb_merge