git-fetch: allow updating the current branch in a bare repository.
[git/gitweb.git] / git-merge.sh
blob477002910ede7f6bc6bcb9a79f6ddebd248f6bd2
1 #!/bin/sh
3 # Copyright (c) 2005 Junio C Hamano
6 USAGE='[-n] [--no-commit] [--squash] [-s <strategy>] [-m=<merge-message>] <commit>+'
8 . git-sh-setup
9 set_reflog_action "merge $*"
11 test -z "$(git ls-files -u)" ||
12 die "You are in a middle of conflicted merge."
14 LF='
17 all_strategies='recur recursive octopus resolve stupid ours'
18 default_twohead_strategies='recursive'
19 default_octopus_strategies='octopus'
20 no_trivial_merge_strategies='ours'
21 use_strategies=
23 index_merge=t
25 dropsave() {
26 rm -f -- "$GIT_DIR/MERGE_HEAD" "$GIT_DIR/MERGE_MSG" \
27 "$GIT_DIR/MERGE_SAVE" || exit 1
30 savestate() {
31 # Stash away any local modifications.
32 git-diff-index -z --name-only $head |
33 cpio -0 -o >"$GIT_DIR/MERGE_SAVE"
36 restorestate() {
37 if test -f "$GIT_DIR/MERGE_SAVE"
38 then
39 git reset --hard $head >/dev/null
40 cpio -iuv <"$GIT_DIR/MERGE_SAVE"
41 git-update-index --refresh >/dev/null
45 finish_up_to_date () {
46 case "$squash" in
48 echo "$1 (nothing to squash)" ;;
49 '')
50 echo "$1" ;;
51 esac
52 dropsave
55 squash_message () {
56 echo Squashed commit of the following:
57 echo
58 git-log --no-merges ^"$head" $remote
61 finish () {
62 if test '' = "$2"
63 then
64 rlogm="$GIT_REFLOG_ACTION"
65 else
66 echo "$2"
67 rlogm="$GIT_REFLOG_ACTION: $2"
69 case "$squash" in
71 echo "Squash commit -- not updating HEAD"
72 squash_message >"$GIT_DIR/SQUASH_MSG"
74 '')
75 case "$merge_msg" in
76 '')
77 echo "No merge message -- not updating HEAD"
80 git-update-ref -m "$rlogm" HEAD "$1" "$head" || exit 1
82 esac
84 esac
85 case "$1" in
86 '')
88 ?*)
89 case "$no_summary" in
90 '')
91 git-diff-tree --stat --summary -M "$head" "$1"
93 esac
95 esac
98 merge_name () {
99 remote="$1"
100 rh=$(git-rev-parse --verify "$remote^0" 2>/dev/null) || return
101 bh=$(git-show-ref -s --verify "refs/heads/$remote" 2>/dev/null)
102 if test "$rh" = "$bh"
103 then
104 echo "$rh branch '$remote' of ."
105 elif truname=$(expr "$remote" : '\(.*\)~[1-9][0-9]*$') &&
106 git-show-ref -q --verify "refs/heads/$truname" 2>/dev/null
107 then
108 echo "$rh branch '$truname' (early part) of ."
109 else
110 echo "$rh commit '$remote'"
114 case "$#" in 0) usage ;; esac
116 have_message=
117 while case "$#" in 0) break ;; esac
119 case "$1" in
120 -n|--n|--no|--no-|--no-s|--no-su|--no-sum|--no-summ|\
121 --no-summa|--no-summar|--no-summary)
122 no_summary=t ;;
123 --sq|--squ|--squa|--squas|--squash)
124 squash=t no_commit=t ;;
125 --no-c|--no-co|--no-com|--no-comm|--no-commi|--no-commit)
126 no_commit=t ;;
127 -s=*|--s=*|--st=*|--str=*|--stra=*|--strat=*|--strate=*|\
128 --strateg=*|--strategy=*|\
129 -s|--s|--st|--str|--stra|--strat|--strate|--strateg|--strategy)
130 case "$#,$1" in
131 *,*=*)
132 strategy=`expr "z$1" : 'z-[^=]*=\(.*\)'` ;;
133 1,*)
134 usage ;;
136 strategy="$2"
137 shift ;;
138 esac
139 case " $all_strategies " in
140 *" $strategy "*)
141 use_strategies="$use_strategies$strategy " ;;
143 die "available strategies are: $all_strategies" ;;
144 esac
146 -m=*|--m=*|--me=*|--mes=*|--mess=*|--messa=*|--messag=*|--message=*)
147 merge_msg=`expr "z$1" : 'z-[^=]*=\(.*\)'`
148 have_message=t
150 -m|--m|--me|--mes|--mess|--messa|--messag|--message)
151 shift
152 case "$#" in
153 1) usage ;;
154 esac
155 merge_msg="$1"
156 have_message=t
158 -*) usage ;;
159 *) break ;;
160 esac
161 shift
162 done
164 # This could be traditional "merge <msg> HEAD <commit>..." and the
165 # way we can tell it is to see if the second token is HEAD, but some
166 # people might have misused the interface and used a committish that
167 # is the same as HEAD there instead. Traditional format never would
168 # have "-m" so it is an additional safety measure to check for it.
170 if test -z "$have_message" &&
171 second_token=$(git-rev-parse --verify "$2^0" 2>/dev/null) &&
172 head_commit=$(git-rev-parse --verify "HEAD" 2>/dev/null) &&
173 test "$second_token" = "$head_commit"
174 then
175 merge_msg="$1"
176 shift
177 head_arg="$1"
178 shift
179 elif ! git-rev-parse --verify HEAD >/dev/null 2>&1
180 then
181 # If the merged head is a valid one there is no reason to
182 # forbid "git merge" into a branch yet to be born. We do
183 # the same for "git pull".
184 if test 1 -ne $#
185 then
186 echo >&2 "Can merge only exactly one commit into empty head"
187 exit 1
190 rh=$(git rev-parse --verify "$1^0") ||
191 die "$1 - not something we can merge"
193 git-update-ref -m "initial pull" HEAD "$rh" "" &&
194 git-read-tree --reset -u HEAD
195 exit
197 else
198 # We are invoked directly as the first-class UI.
199 head_arg=HEAD
201 # All the rest are the commits being merged; prepare
202 # the standard merge summary message to be appended to
203 # the given message. If remote is invalid we will die
204 # later in the common codepath so we discard the error
205 # in this loop.
206 merge_name=$(for remote
208 merge_name "$remote"
209 done | git-fmt-merge-msg
211 merge_msg="${merge_msg:+$merge_msg$LF$LF}$merge_name"
213 head=$(git-rev-parse --verify "$head_arg"^0) || usage
215 # All the rest are remote heads
216 test "$#" = 0 && usage ;# we need at least one remote head.
218 remoteheads=
219 for remote
221 remotehead=$(git-rev-parse --verify "$remote"^0 2>/dev/null) ||
222 die "$remote - not something we can merge"
223 remoteheads="${remoteheads}$remotehead "
224 eval GITHEAD_$remotehead='"$remote"'
225 export GITHEAD_$remotehead
226 done
227 set x $remoteheads ; shift
229 case "$use_strategies" in
231 case "$#" in
233 var="`git-repo-config --get pull.twohead`"
234 if test -n "$var"
235 then
236 use_strategies="$var"
237 else
238 use_strategies="$default_twohead_strategies"
239 fi ;;
241 var="`git-repo-config --get pull.octopus`"
242 if test -n "$var"
243 then
244 use_strategies="$var"
245 else
246 use_strategies="$default_octopus_strategies"
247 fi ;;
248 esac
250 esac
252 for s in $use_strategies
254 case " $s " in
255 *" $no_trivial_merge_strategies "*)
256 index_merge=f
257 break
259 esac
260 done
262 case "$#" in
264 common=$(git-merge-base --all $head "$@")
267 common=$(git-show-branch --merge-base $head "$@")
269 esac
270 echo "$head" >"$GIT_DIR/ORIG_HEAD"
272 case "$index_merge,$#,$common,$no_commit" in
273 f,*)
274 # We've been told not to try anything clever. Skip to real merge.
276 ?,*,'',*)
277 # No common ancestors found. We need a real merge.
279 ?,1,"$1",*)
280 # If head can reach all the merge then we are up to date.
281 # but first the most common case of merging one remote.
282 finish_up_to_date "Already up-to-date."
283 exit 0
285 ?,1,"$head",*)
286 # Again the most common case of merging one remote.
287 echo "Updating $(git-rev-parse --short $head)..$(git-rev-parse --short $1)"
288 git-update-index --refresh 2>/dev/null
289 new_head=$(git-rev-parse --verify "$1^0") &&
290 git-read-tree -v -m -u --exclude-per-directory=.gitignore $head "$new_head" &&
291 finish "$new_head" "Fast forward"
292 dropsave
293 exit 0
295 ?,1,?*"$LF"?*,*)
296 # We are not doing octopus and not fast forward. Need a
297 # real merge.
299 ?,1,*,)
300 # We are not doing octopus, not fast forward, and have only
301 # one common. See if it is really trivial.
302 git var GIT_COMMITTER_IDENT >/dev/null || exit
304 echo "Trying really trivial in-index merge..."
305 git-update-index --refresh 2>/dev/null
306 if git-read-tree --trivial -m -u -v $common $head "$1" &&
307 result_tree=$(git-write-tree)
308 then
309 echo "Wonderful."
310 result_commit=$(
311 echo "$merge_msg" |
312 git-commit-tree $result_tree -p HEAD -p "$1"
313 ) || exit
314 finish "$result_commit" "In-index merge"
315 dropsave
316 exit 0
318 echo "Nope."
321 # An octopus. If we can reach all the remote we are up to date.
322 up_to_date=t
323 for remote
325 common_one=$(git-merge-base --all $head $remote)
326 if test "$common_one" != "$remote"
327 then
328 up_to_date=f
329 break
331 done
332 if test "$up_to_date" = t
333 then
334 finish_up_to_date "Already up-to-date. Yeeah!"
335 exit 0
338 esac
340 # We are going to make a new commit.
341 git var GIT_COMMITTER_IDENT >/dev/null || exit
343 # At this point, we need a real merge. No matter what strategy
344 # we use, it would operate on the index, possibly affecting the
345 # working tree, and when resolved cleanly, have the desired tree
346 # in the index -- this means that the index must be in sync with
347 # the $head commit. The strategies are responsible to ensure this.
349 case "$use_strategies" in
350 ?*' '?*)
351 # Stash away the local changes so that we can try more than one.
352 savestate
353 single_strategy=no
356 rm -f "$GIT_DIR/MERGE_SAVE"
357 single_strategy=yes
359 esac
361 result_tree= best_cnt=-1 best_strategy= wt_strategy=
362 merge_was_ok=
363 for strategy in $use_strategies
365 test "$wt_strategy" = '' || {
366 echo "Rewinding the tree to pristine..."
367 restorestate
369 case "$single_strategy" in
371 echo "Trying merge strategy $strategy..."
373 esac
375 # Remember which strategy left the state in the working tree
376 wt_strategy=$strategy
378 git-merge-$strategy $common -- "$head_arg" "$@"
379 exit=$?
380 if test "$no_commit" = t && test "$exit" = 0
381 then
382 merge_was_ok=t
383 exit=1 ;# pretend it left conflicts.
386 test "$exit" = 0 || {
388 # The backend exits with 1 when conflicts are left to be resolved,
389 # with 2 when it does not handle the given merge at all.
391 if test "$exit" -eq 1
392 then
393 cnt=`{
394 git-diff-files --name-only
395 git-ls-files --unmerged
396 } | wc -l`
397 if test $best_cnt -le 0 -o $cnt -le $best_cnt
398 then
399 best_strategy=$strategy
400 best_cnt=$cnt
403 continue
406 # Automerge succeeded.
407 result_tree=$(git-write-tree) && break
408 done
410 # If we have a resulting tree, that means the strategy module
411 # auto resolved the merge cleanly.
412 if test '' != "$result_tree"
413 then
414 parents=$(git-show-branch --independent "$head" "$@" | sed -e 's/^/-p /')
415 result_commit=$(echo "$merge_msg" | git-commit-tree $result_tree $parents) || exit
416 finish "$result_commit" "Merge made by $wt_strategy."
417 dropsave
418 exit 0
421 # Pick the result from the best strategy and have the user fix it up.
422 case "$best_strategy" in
424 restorestate
425 case "$use_strategies" in
426 ?*' '?*)
427 echo >&2 "No merge strategy handled the merge."
430 echo >&2 "Merge with strategy $use_strategies failed."
432 esac
433 exit 2
435 "$wt_strategy")
436 # We already have its result in the working tree.
439 echo "Rewinding the tree to pristine..."
440 restorestate
441 echo "Using the $best_strategy to prepare resolving by hand."
442 git-merge-$best_strategy $common -- "$head_arg" "$@"
444 esac
446 if test "$squash" = t
447 then
448 finish
449 else
450 for remote
452 echo $remote
453 done >"$GIT_DIR/MERGE_HEAD"
454 echo "$merge_msg" >"$GIT_DIR/MERGE_MSG"
457 if test "$merge_was_ok" = t
458 then
459 echo >&2 \
460 "Automatic merge went well; stopped before committing as requested"
461 exit 0
462 else
464 echo '
465 Conflicts:
467 git ls-files --unmerged |
468 sed -e 's/^[^ ]* / /' |
469 uniq
470 } >>"$GIT_DIR/MERGE_MSG"
471 if test -d "$GIT_DIR/rr-cache"
472 then
473 git-rerere
475 die "Automatic merge failed; fix conflicts and then commit the result."