gitweb: Support for 'forks'
[git.git] / git-merge.sh
blobcb094388bb5c830d37a790f5e7bbf13e8c61352a
1 #!/bin/sh
3 # Copyright (c) 2005 Junio C Hamano
6 USAGE='[-n] [--no-commit] [--squash] [-s <strategy>]... <merge-message> <head> <remote>+'
7 . git-sh-setup
9 LF='
12 all_strategies='recur recursive recursive-old octopus resolve stupid ours'
13 default_twohead_strategies='recursive'
14 default_octopus_strategies='octopus'
15 no_trivial_merge_strategies='ours'
16 use_strategies=
18 index_merge=t
19 if test "@@NO_PYTHON@@"; then
20 all_strategies='recur recursive resolve octopus stupid ours'
23 dropsave() {
24 rm -f -- "$GIT_DIR/MERGE_HEAD" "$GIT_DIR/MERGE_MSG" \
25 "$GIT_DIR/MERGE_SAVE" || exit 1
28 savestate() {
29 # Stash away any local modifications.
30 git-diff-index -z --name-only $head |
31 cpio -0 -o >"$GIT_DIR/MERGE_SAVE"
34 restorestate() {
35 if test -f "$GIT_DIR/MERGE_SAVE"
36 then
37 git reset --hard $head
38 cpio -iuv <"$GIT_DIR/MERGE_SAVE"
39 git-update-index --refresh >/dev/null
43 finish_up_to_date () {
44 case "$squash" in
46 echo "$1 (nothing to squash)" ;;
47 '')
48 echo "$1" ;;
49 esac
50 dropsave
53 squash_message () {
54 echo Squashed commit of the following:
55 echo
56 git-log --no-merges ^"$head" $remote
59 finish () {
60 if test '' = "$2"
61 then
62 rlogm="$rloga"
63 else
64 echo "$2"
65 rlogm="$rloga: $2"
67 case "$squash" in
69 echo "Squash commit -- not updating HEAD"
70 squash_message >"$GIT_DIR/SQUASH_MSG"
72 '')
73 case "$merge_msg" in
74 '')
75 echo "No merge message -- not updating HEAD"
78 git-update-ref -m "$rlogm" HEAD "$1" "$head" || exit 1
80 esac
82 esac
83 case "$1" in
84 '')
86 ?*)
87 case "$no_summary" in
88 '')
89 git-diff-tree --stat --summary -M "$head" "$1"
91 esac
93 esac
96 case "$#" in 0) usage ;; esac
98 rloga=
99 while case "$#" in 0) break ;; esac
101 case "$1" in
102 -n|--n|--no|--no-|--no-s|--no-su|--no-sum|--no-summ|\
103 --no-summa|--no-summar|--no-summary)
104 no_summary=t ;;
105 --sq|--squ|--squa|--squas|--squash)
106 squash=t no_commit=t ;;
107 --no-c|--no-co|--no-com|--no-comm|--no-commi|--no-commit)
108 no_commit=t ;;
109 -s=*|--s=*|--st=*|--str=*|--stra=*|--strat=*|--strate=*|\
110 --strateg=*|--strategy=*|\
111 -s|--s|--st|--str|--stra|--strat|--strate|--strateg|--strategy)
112 case "$#,$1" in
113 *,*=*)
114 strategy=`expr "z$1" : 'z-[^=]*=\(.*\)'` ;;
115 1,*)
116 usage ;;
118 strategy="$2"
119 shift ;;
120 esac
121 case " $all_strategies " in
122 *" $strategy "*)
123 use_strategies="$use_strategies$strategy " ;;
125 die "available strategies are: $all_strategies" ;;
126 esac
128 --reflog-action=*)
129 rloga=`expr "z$1" : 'z-[^=]*=\(.*\)'`
131 -*) usage ;;
132 *) break ;;
133 esac
134 shift
135 done
137 merge_msg="$1"
138 shift
139 head_arg="$1"
140 head=$(git-rev-parse --verify "$1"^0) || usage
141 shift
143 # All the rest are remote heads
144 test "$#" = 0 && usage ;# we need at least one remote head.
145 test "$rloga" = '' && rloga="merge: $@"
147 remoteheads=
148 for remote
150 remotehead=$(git-rev-parse --verify "$remote"^0) ||
151 die "$remote - not something we can merge"
152 remoteheads="${remoteheads}$remotehead "
153 done
154 set x $remoteheads ; shift
156 case "$use_strategies" in
158 case "$#" in
160 use_strategies="$default_twohead_strategies" ;;
162 use_strategies="$default_octopus_strategies" ;;
163 esac
165 esac
167 for s in $use_strategies
169 case " $s " in
170 *" $no_trivial_merge_strategies "*)
171 index_merge=f
172 break
174 esac
175 done
177 case "$#" in
179 common=$(git-merge-base --all $head "$@")
182 common=$(git-show-branch --merge-base $head "$@")
184 esac
185 echo "$head" >"$GIT_DIR/ORIG_HEAD"
187 case "$index_merge,$#,$common,$no_commit" in
188 f,*)
189 # We've been told not to try anything clever. Skip to real merge.
191 ?,*,'',*)
192 # No common ancestors found. We need a real merge.
194 ?,1,"$1",*)
195 # If head can reach all the merge then we are up to date.
196 # but first the most common case of merging one remote.
197 finish_up_to_date "Already up-to-date."
198 exit 0
200 ?,1,"$head",*)
201 # Again the most common case of merging one remote.
202 echo "Updating $(git-rev-parse --short $head)..$(git-rev-parse --short $1)"
203 git-update-index --refresh 2>/dev/null
204 new_head=$(git-rev-parse --verify "$1^0") &&
205 git-read-tree -u -v -m $head "$new_head" &&
206 finish "$new_head" "Fast forward"
207 dropsave
208 exit 0
210 ?,1,?*"$LF"?*,*)
211 # We are not doing octopus and not fast forward. Need a
212 # real merge.
214 ?,1,*,)
215 # We are not doing octopus, not fast forward, and have only
216 # one common. See if it is really trivial.
217 git var GIT_COMMITTER_IDENT >/dev/null || exit
219 echo "Trying really trivial in-index merge..."
220 git-update-index --refresh 2>/dev/null
221 if git-read-tree --trivial -m -u -v $common $head "$1" &&
222 result_tree=$(git-write-tree)
223 then
224 echo "Wonderful."
225 result_commit=$(
226 echo "$merge_msg" |
227 git-commit-tree $result_tree -p HEAD -p "$1"
228 ) || exit
229 finish "$result_commit" "In-index merge"
230 dropsave
231 exit 0
233 echo "Nope."
236 # An octopus. If we can reach all the remote we are up to date.
237 up_to_date=t
238 for remote
240 common_one=$(git-merge-base --all $head $remote)
241 if test "$common_one" != "$remote"
242 then
243 up_to_date=f
244 break
246 done
247 if test "$up_to_date" = t
248 then
249 finish_up_to_date "Already up-to-date. Yeeah!"
250 exit 0
253 esac
255 # We are going to make a new commit.
256 git var GIT_COMMITTER_IDENT >/dev/null || exit
258 # At this point, we need a real merge. No matter what strategy
259 # we use, it would operate on the index, possibly affecting the
260 # working tree, and when resolved cleanly, have the desired tree
261 # in the index -- this means that the index must be in sync with
262 # the $head commit. The strategies are responsible to ensure this.
264 case "$use_strategies" in
265 ?*' '?*)
266 # Stash away the local changes so that we can try more than one.
267 savestate
268 single_strategy=no
271 rm -f "$GIT_DIR/MERGE_SAVE"
272 single_strategy=yes
274 esac
276 result_tree= best_cnt=-1 best_strategy= wt_strategy=
277 merge_was_ok=
278 for strategy in $use_strategies
280 test "$wt_strategy" = '' || {
281 echo "Rewinding the tree to pristine..."
282 restorestate
284 case "$single_strategy" in
286 echo "Trying merge strategy $strategy..."
288 esac
290 # Remember which strategy left the state in the working tree
291 wt_strategy=$strategy
293 git-merge-$strategy $common -- "$head_arg" "$@"
294 exit=$?
295 if test "$no_commit" = t && test "$exit" = 0
296 then
297 merge_was_ok=t
298 exit=1 ;# pretend it left conflicts.
301 test "$exit" = 0 || {
303 # The backend exits with 1 when conflicts are left to be resolved,
304 # with 2 when it does not handle the given merge at all.
306 if test "$exit" -eq 1
307 then
308 cnt=`{
309 git-diff-files --name-only
310 git-ls-files --unmerged
311 } | wc -l`
312 if test $best_cnt -le 0 -o $cnt -le $best_cnt
313 then
314 best_strategy=$strategy
315 best_cnt=$cnt
318 continue
321 # Automerge succeeded.
322 result_tree=$(git-write-tree) && break
323 done
325 # If we have a resulting tree, that means the strategy module
326 # auto resolved the merge cleanly.
327 if test '' != "$result_tree"
328 then
329 parents=$(git-show-branch --independent "$head" "$@" | sed -e 's/^/-p /')
330 result_commit=$(echo "$merge_msg" | git-commit-tree $result_tree $parents) || exit
331 finish "$result_commit" "Merge made by $wt_strategy."
332 dropsave
333 exit 0
336 # Pick the result from the best strategy and have the user fix it up.
337 case "$best_strategy" in
339 restorestate
340 echo >&2 "No merge strategy handled the merge."
341 exit 2
343 "$wt_strategy")
344 # We already have its result in the working tree.
347 echo "Rewinding the tree to pristine..."
348 restorestate
349 echo "Using the $best_strategy to prepare resolving by hand."
350 git-merge-$best_strategy $common -- "$head_arg" "$@"
352 esac
354 if test "$squash" = t
355 then
356 finish
357 else
358 for remote
360 echo $remote
361 done >"$GIT_DIR/MERGE_HEAD"
362 echo "$merge_msg" >"$GIT_DIR/MERGE_MSG"
365 if test "$merge_was_ok" = t
366 then
367 echo >&2 \
368 "Automatic merge went well; stopped before committing as requested"
369 exit 0
370 else
372 echo '
373 Conflicts:
375 git ls-files --unmerged |
376 sed -e 's/^[^ ]* / /' |
377 uniq
378 } >>"$GIT_DIR/MERGE_MSG"
379 if test -d "$GIT_DIR/rr-cache"
380 then
381 git-rerere
383 die "Automatic merge failed; fix conflicts and then commit the result."