parse-remote and ls-remote clean-up.
[git/git.git] / git-merge.sh
CommitLineData
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1#!/bin/sh
2#
3# Copyright (c) 2005 Junio C Hamano
4#
5
6. git-sh-setup || die "Not a git archive"
7
8LF='
9'
10
11usage () {
123ee3ca 12 die "git-merge [-n] [--no-commit] [-s <strategy>]... <merge-message> <head> <remote>+"
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13}
14
64da9e60 15all_strategies='recursive octopus resolve stupid ours'
fbf8ac21 16default_strategies='recursive'
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17use_strategies=
18
a9358240 19dropsave() {
deca7e8c 20 rm -f -- "$GIT_DIR/MERGE_HEAD" "$GIT_DIR/MERGE_MSG" \
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21 "$GIT_DIR/MERGE_SAVE" || exit 1
22}
23
24savestate() {
60fa0560 25 # Stash away any local modifications.
50b8e355 26 git-diff-index -z --name-only $head |
88f8f0a5 27 cpio -0 -o >"$GIT_DIR/MERGE_SAVE"
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28}
29
30restorestate() {
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31 if test -f "$GIT_DIR/MERGE_SAVE"
32 then
33 git reset --hard $head
34 cpio -iuv <"$GIT_DIR/MERGE_SAVE"
35 git-update-index --refresh >/dev/null
36 fi
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37}
38
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39finish () {
40 test '' = "$2" || echo "$2"
41 case "$merge_msg" in
42 '')
43 echo "No merge message -- not updating HEAD"
44 ;;
45 *)
46 git-update-ref HEAD "$1" "$head" || exit 1
47 ;;
48 esac
49
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50 case "$no_summary" in
51 '')
4f692b19 52 git-diff-tree -p -M "$head" "$1" |
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53 git-apply --stat --summary
54 ;;
55 esac
56}
57
58while case "$#" in 0) break ;; esac
59do
60 case "$1" in
61 -n|--n|--no|--no-|--no-s|--no-su|--no-sum|--no-summ|\
62 --no-summa|--no-summar|--no-summary)
63 no_summary=t ;;
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64 --no-c|--no-co|--no-com|--no-comm|--no-commi|--no-commit)
65 no_commit=t ;;
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66 -s=*|--s=*|--st=*|--str=*|--stra=*|--strat=*|--strate=*|\
67 --strateg=*|--strategy=*|\
68 -s|--s|--st|--str|--stra|--strat|--strate|--strateg|--strategy)
69 case "$#,$1" in
70 *,*=*)
71 strategy=`expr "$1" : '-[^=]*=\(.*\)'` ;;
f88ed172 72 1,*)
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73 usage ;;
74 *)
75 strategy="$2"
76 shift ;;
77 esac
78 case " $all_strategies " in
79 *" $strategy "*)
80 use_strategies="$use_strategies$strategy " ;;
81 *)
82 die "available strategies are: $all_strategies" ;;
83 esac
84 ;;
85 -*) usage ;;
86 *) break ;;
87 esac
88 shift
89done
90
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91test "$#" -le 2 && usage ;# we need at least two heads.
92
93merge_msg="$1"
94shift
8cc01e50 95head_arg="$1"
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96head=$(git-rev-parse --verify "$1"^0) || usage
97shift
98
99# All the rest are remote heads
100for remote
101do
102 git-rev-parse --verify "$remote"^0 >/dev/null ||
103 die "$remote - not something we can merge"
104done
105
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106case "$#" in
1071)
108 common=$(git-merge-base --all $head "$@")
109 ;;
110*)
111 common=$(git-show-branch --merge-base $head "$@")
112 ;;
113esac
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114echo "$head" >"$GIT_DIR/ORIG_HEAD"
115
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116case "$#,$common,$no_commit" in
117*,'',*)
88f8f0a5 118 # No common ancestors found. We need a real merge.
91063bbc 119 ;;
123ee3ca 1201,"$1",*)
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121 # If head can reach all the merge then we are up to date.
122 # but first the most common case of merging one remote
4f692b19 123 echo "Already up-to-date."
a9358240 124 dropsave
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125 exit 0
126 ;;
123ee3ca 1271,"$head",*)
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128 # Again the most common case of merging one remote.
129 echo "Updating from $head to $1."
130 git-update-index --refresh 2>/dev/null
bf7960eb 131 new_head=$(git-rev-parse --verify "$1^0") &&
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132 git-read-tree -u -m $head "$new_head" &&
133 finish "$new_head" "Fast forward"
a9358240 134 dropsave
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135 exit 0
136 ;;
123ee3ca 1371,?*"$LF"?*,*)
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138 # We are not doing octopus and not fast forward. Need a
139 # real merge.
140 ;;
123ee3ca 1411,*,)
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142 # We are not doing octopus, not fast forward, and have only
143 # one common. See if it is really trivial.
144 echo "Trying really trivial in-index merge..."
145 git-update-index --refresh 2>/dev/null
146 if git-read-tree --trivial -m -u $common $head "$1" &&
147 result_tree=$(git-write-tree)
148 then
149 echo "Wonderful."
150 result_commit=$(
151 echo "$merge_msg" |
152 git-commit-tree $result_tree -p HEAD -p "$1"
153 ) || exit
4f692b19 154 finish "$result_commit" "In-index merge"
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155 dropsave
156 exit 0
157 fi
158 echo "Nope."
159 ;;
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160*)
161 # An octopus. If we can reach all the remote we are up to date.
162 up_to_date=t
163 for remote
164 do
13956670 165 common_one=$(git-merge-base --all $head $remote)
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166 if test "$common_one" != "$remote"
167 then
168 up_to_date=f
169 break
170 fi
171 done
172 if test "$up_to_date" = t
173 then
174 echo "Already up-to-date. Yeeah!"
a9358240 175 dropsave
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176 exit 0
177 fi
178 ;;
179esac
180
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181case "$use_strategies" in
182'')
183 case "$#" in
184 1)
185 use_strategies="$default_strategies" ;;
186 *)
187 use_strategies=octopus ;;
188 esac
189 ;;
190esac
191
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192# At this point, we need a real merge. No matter what strategy
193# we use, it would operate on the index, possibly affecting the
194# working tree, and when resolved cleanly, have the desired tree
195# in the index -- this means that the index must be in sync with
60fa0560 196# the $head commit. The strategies are responsible to ensure this.
91063bbc 197
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198case "$use_strategies" in
199?*' '?*)
200 # Stash away the local changes so that we can try more than one.
201 savestate
202 single_strategy=no
203 ;;
204*)
deca7e8c 205 rm -f "$GIT_DIR/MERGE_SAVE"
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206 single_strategy=yes
207 ;;
208esac
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209
210result_tree= best_cnt=-1 best_strategy= wt_strategy=
211for strategy in $use_strategies
212do
213 test "$wt_strategy" = '' || {
214 echo "Rewinding the tree to pristine..."
a9358240 215 restorestate
91063bbc 216 }
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217 case "$single_strategy" in
218 no)
219 echo "Trying merge strategy $strategy..."
220 ;;
221 esac
222
223 # Remember which strategy left the state in the working tree
91063bbc 224 wt_strategy=$strategy
a9358240 225
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226 git-merge-$strategy $common -- "$head_arg" "$@"
227 exit=$?
228 if test "$no_commit" = t && test "$exit" = 0
229 then
230 exit=1 ;# pretend it left conflicts.
231 fi
232
233 test "$exit" = 0 || {
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234
235 # The backend exits with 1 when conflicts are left to be resolved,
236 # with 2 when it does not handle the given merge at all.
237
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238 if test "$exit" -eq 1
239 then
240 cnt=`{
241 git-diff-files --name-only
242 git-ls-files --unmerged
243 } | wc -l`
244 if test $best_cnt -le 0 -o $cnt -le $best_cnt
245 then
246 best_strategy=$strategy
247 best_cnt=$cnt
248 fi
249 fi
250 continue
251 }
252
253 # Automerge succeeded.
254 result_tree=$(git-write-tree) && break
255done
256
257# If we have a resulting tree, that means the strategy module
258# auto resolved the merge cleanly.
259if test '' != "$result_tree"
260then
261 parents="-p $head"
262 for remote
263 do
264 parents="$parents -p $remote"
265 done
bf7960eb 266 result_commit=$(echo "$merge_msg" | git-commit-tree $result_tree $parents) || exit
4f692b19 267 finish "$result_commit" "Merge $result_commit, made by $wt_strategy."
a9358240 268 dropsave
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269 exit 0
270fi
271
272# Pick the result from the best strategy and have the user fix it up.
273case "$best_strategy" in
274'')
a9358240 275 restorestate
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276 die "No merge strategy handled the merge."
277 ;;
278"$wt_strategy")
279 # We already have its result in the working tree.
280 ;;
281*)
282 echo "Rewinding the tree to pristine..."
a9358240 283 restorestate
91063bbc 284 echo "Using the $best_strategy to prepare resolving by hand."
a9358240 285 git-merge-$best_strategy $common -- "$head_arg" "$@"
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286 ;;
287esac
288for remote
289do
290 echo $remote
291done >"$GIT_DIR/MERGE_HEAD"
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292echo $merge_msg >"$GIT_DIR/MERGE_MSG"
293
123ee3ca 294die "Automatic merge failed/prevented; fix up by hand"