doc: discuss textconv versus external diff drivers
[git] / git-pull.sh
1 #!/bin/sh
2 #
3 # Copyright (c) 2005 Junio C Hamano
4 #
5 # Fetch one or more remote refs and merge it/them into the current HEAD.
6
7 USAGE='[-n | --no-stat] [--[no-]commit] [--[no-]squash] [--[no-]ff] [-s strategy]... [<fetch-options>] <repo> <head>...'
8 LONG_USAGE='Fetch one or more remote refs and merge it/them into the current HEAD.'
9 SUBDIRECTORY_OK=Yes
10 OPTIONS_SPEC=
11 . git-sh-setup
12 set_reflog_action "pull $*"
13 require_work_tree
14 cd_to_toplevel
15
16
17 die_conflict () {
18     git diff-index --cached --name-status -r --ignore-submodules HEAD --
19     if [ $(git config --bool --get advice.resolveConflict || echo true) = "true" ]; then
20         die "Pull is not possible because you have unmerged files.
21 Please, fix them up in the work tree, and then use 'git add/rm <file>'
22 as appropriate to mark resolution, or use 'git commit -a'."
23     else
24         die "Pull is not possible because you have unmerged files."
25     fi
26 }
27
28 die_merge () {
29     if [ $(git config --bool --get advice.resolveConflict || echo true) = "true" ]; then
30         die "You have not concluded your merge (MERGE_HEAD exists).
31 Please, commit your changes before you can merge."
32     else
33         die "You have not concluded your merge (MERGE_HEAD exists)."
34     fi
35 }
36
37 test -z "$(git ls-files -u)" || die_conflict
38 test -f "$GIT_DIR/MERGE_HEAD" && die_merge
39
40 strategy_args= diffstat= no_commit= squash= no_ff= ff_only=
41 log_arg= verbosity= progress= recurse_submodules=
42 merge_args=
43 curr_branch=$(git symbolic-ref -q HEAD)
44 curr_branch_short="${curr_branch#refs/heads/}"
45 rebase=$(git config --bool branch.$curr_branch_short.rebase)
46 dry_run=
47 while :
48 do
49         case "$1" in
50         -q|--quiet)
51                 verbosity="$verbosity -q" ;;
52         -v|--verbose)
53                 verbosity="$verbosity -v" ;;
54         --progress)
55                 progress=--progress ;;
56         --no-progress)
57                 progress=--no-progress ;;
58         -n|--no-stat|--no-summary)
59                 diffstat=--no-stat ;;
60         --stat|--summary)
61                 diffstat=--stat ;;
62         --log|--no-log)
63                 log_arg=$1 ;;
64         --no-c|--no-co|--no-com|--no-comm|--no-commi|--no-commit)
65                 no_commit=--no-commit ;;
66         --c|--co|--com|--comm|--commi|--commit)
67                 no_commit=--commit ;;
68         --sq|--squ|--squa|--squas|--squash)
69                 squash=--squash ;;
70         --no-sq|--no-squ|--no-squa|--no-squas|--no-squash)
71                 squash=--no-squash ;;
72         --ff)
73                 no_ff=--ff ;;
74         --no-ff)
75                 no_ff=--no-ff ;;
76         --ff-only)
77                 ff_only=--ff-only ;;
78         -s=*|--s=*|--st=*|--str=*|--stra=*|--strat=*|--strate=*|\
79                 --strateg=*|--strategy=*|\
80         -s|--s|--st|--str|--stra|--strat|--strate|--strateg|--strategy)
81                 case "$#,$1" in
82                 *,*=*)
83                         strategy=`expr "z$1" : 'z-[^=]*=\(.*\)'` ;;
84                 1,*)
85                         usage ;;
86                 *)
87                         strategy="$2"
88                         shift ;;
89                 esac
90                 strategy_args="${strategy_args}-s $strategy "
91                 ;;
92         -X*)
93                 case "$#,$1" in
94                 1,-X)
95                         usage ;;
96                 *,-X)
97                         xx="-X $(git rev-parse --sq-quote "$2")"
98                         shift ;;
99                 *,*)
100                         xx=$(git rev-parse --sq-quote "$1") ;;
101                 esac
102                 merge_args="$merge_args$xx "
103                 ;;
104         -r|--r|--re|--reb|--reba|--rebas|--rebase)
105                 rebase=true
106                 ;;
107         --no-r|--no-re|--no-reb|--no-reba|--no-rebas|--no-rebase)
108                 rebase=false
109                 ;;
110         --recurse-submodules)
111                 recurse_submodules=--recurse-submodules
112                 ;;
113         --recurse-submodules=*)
114                 recurse_submodules="$1"
115                 ;;
116         --no-recurse-submodules)
117                 recurse_submodules=--no-recurse-submodules
118                 ;;
119         --d|--dr|--dry|--dry-|--dry-r|--dry-ru|--dry-run)
120                 dry_run=--dry-run
121                 ;;
122         -h|--h|--he|--hel|--help|--help-|--help-a|--help-al|--help-all)
123                 usage
124                 ;;
125         *)
126                 # Pass thru anything that may be meant for fetch.
127                 break
128                 ;;
129         esac
130         shift
131 done
132
133 error_on_no_merge_candidates () {
134         exec >&2
135         for opt
136         do
137                 case "$opt" in
138                 -t|--t|--ta|--tag|--tags)
139                         echo "Fetching tags only, you probably meant:"
140                         echo "  git fetch --tags"
141                         exit 1
142                 esac
143         done
144
145         if test true = "$rebase"
146         then
147                 op_type=rebase
148                 op_prep=against
149         else
150                 op_type=merge
151                 op_prep=with
152         fi
153
154         curr_branch=${curr_branch#refs/heads/}
155         upstream=$(git config "branch.$curr_branch.merge")
156         remote=$(git config "branch.$curr_branch.remote")
157
158         if [ $# -gt 1 ]; then
159                 if [ "$rebase" = true ]; then
160                         printf "There is no candidate for rebasing against "
161                 else
162                         printf "There are no candidates for merging "
163                 fi
164                 echo "among the refs that you just fetched."
165                 echo "Generally this means that you provided a wildcard refspec which had no"
166                 echo "matches on the remote end."
167         elif [ $# -gt 0 ] && [ "$1" != "$remote" ]; then
168                 echo "You asked to pull from the remote '$1', but did not specify"
169                 echo "a branch. Because this is not the default configured remote"
170                 echo "for your current branch, you must specify a branch on the command line."
171         elif [ -z "$curr_branch" -o -z "$upstream" ]; then
172                 . git-parse-remote
173                 error_on_missing_default_upstream "pull" $op_type $op_prep \
174                         "git pull <repository> <refspec>"
175         else
176                 echo "Your configuration specifies to $op_type $op_prep the ref '${upstream#refs/heads/}'"
177                 echo "from the remote, but no such ref was fetched."
178         fi
179         exit 1
180 }
181
182 test true = "$rebase" && {
183         if ! git rev-parse -q --verify HEAD >/dev/null
184         then
185                 # On an unborn branch
186                 if test -f "$GIT_DIR/index"
187                 then
188                         die "updating an unborn branch with changes added to the index"
189                 fi
190         else
191                 require_clean_work_tree "pull with rebase" "Please commit or stash them."
192         fi
193         oldremoteref= &&
194         . git-parse-remote &&
195         remoteref="$(get_remote_merge_branch "$@" 2>/dev/null)" &&
196         oldremoteref="$(git rev-parse -q --verify "$remoteref")" &&
197         for reflog in $(git rev-list -g $remoteref 2>/dev/null)
198         do
199                 if test "$reflog" = "$(git merge-base $reflog $curr_branch)"
200                 then
201                         oldremoteref="$reflog"
202                         break
203                 fi
204         done
205 }
206 orig_head=$(git rev-parse -q --verify HEAD)
207 git fetch $verbosity $progress $dry_run $recurse_submodules --update-head-ok "$@" || exit 1
208 test -z "$dry_run" || exit 0
209
210 curr_head=$(git rev-parse -q --verify HEAD)
211 if test -n "$orig_head" && test "$curr_head" != "$orig_head"
212 then
213         # The fetch involved updating the current branch.
214
215         # The working tree and the index file is still based on the
216         # $orig_head commit, but we are merging into $curr_head.
217         # First update the working tree to match $curr_head.
218
219         echo >&2 "Warning: fetch updated the current branch head."
220         echo >&2 "Warning: fast-forwarding your working tree from"
221         echo >&2 "Warning: commit $orig_head."
222         git update-index -q --refresh
223         git read-tree -u -m "$orig_head" "$curr_head" ||
224                 die 'Cannot fast-forward your working tree.
225 After making sure that you saved anything precious from
226 $ git diff '$orig_head'
227 output, run
228 $ git reset --hard
229 to recover.'
230
231 fi
232
233 merge_head=$(sed -e '/  not-for-merge   /d' \
234         -e 's/  .*//' "$GIT_DIR"/FETCH_HEAD | \
235         tr '\012' ' ')
236
237 case "$merge_head" in
238 '')
239         error_on_no_merge_candidates "$@"
240         ;;
241 ?*' '?*)
242         if test -z "$orig_head"
243         then
244                 die "Cannot merge multiple branches into empty head"
245         fi
246         if test true = "$rebase"
247         then
248                 die "Cannot rebase onto multiple branches"
249         fi
250         ;;
251 esac
252
253 if test -z "$orig_head"
254 then
255         git update-ref -m "initial pull" HEAD $merge_head "$curr_head" &&
256         git read-tree -m -u HEAD || exit 1
257         exit
258 fi
259
260 if test true = "$rebase"
261 then
262         o=$(git show-branch --merge-base $curr_branch $merge_head $oldremoteref)
263         if test "$oldremoteref" = "$o"
264         then
265                 unset oldremoteref
266         fi
267 fi
268
269 merge_name=$(git fmt-merge-msg $log_arg <"$GIT_DIR/FETCH_HEAD") || exit
270 case "$rebase" in
271 true)
272         eval="git-rebase $diffstat $strategy_args $merge_args"
273         eval="$eval --onto $merge_head ${oldremoteref:-$merge_head}"
274         ;;
275 *)
276         eval="git-merge $diffstat $no_commit $squash $no_ff $ff_only"
277         eval="$eval  $log_arg $strategy_args $merge_args $verbosity $progress"
278         eval="$eval \"\$merge_name\" HEAD $merge_head"
279         ;;
280 esac
281 eval "exec $eval"