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