git-cherry: document limit and add diagram
[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-summary] [--no-commit] [-s strategy]... [<fetch-options>] <repo> <head>...'
8 LONG_USAGE='Fetch one or more remote refs and merge it/them into the current HEAD.'
9 . git-sh-setup
10
11 strategy_args= no_summary= no_commit= squash=
12 while case "$#,$1" in 0) break ;; *,-*) ;; *) break ;; esac
13 do
14         case "$1" in
15         -n|--n|--no|--no-|--no-s|--no-su|--no-sum|--no-summ|\
16                 --no-summa|--no-summar|--no-summary)
17                 no_summary=-n ;;
18         --no-c|--no-co|--no-com|--no-comm|--no-commi|--no-commit)
19                 no_commit=--no-commit ;;
20         --sq|--squ|--squa|--squas|--squash)
21                 squash=--squash ;;
22         -s=*|--s=*|--st=*|--str=*|--stra=*|--strat=*|--strate=*|\
23                 --strateg=*|--strategy=*|\
24         -s|--s|--st|--str|--stra|--strat|--strate|--strateg|--strategy)
25                 case "$#,$1" in
26                 *,*=*)
27                         strategy=`expr "z$1" : 'z-[^=]*=\(.*\)'` ;;
28                 1,*)
29                         usage ;;
30                 *)
31                         strategy="$2"
32                         shift ;;
33                 esac
34                 strategy_args="${strategy_args}-s $strategy "
35                 ;;
36         -h|--h|--he|--hel|--help)
37                 usage
38                 ;;
39         -*)
40                 # Pass thru anything that is meant for fetch.
41                 break
42                 ;;
43         esac
44         shift
45 done
46
47 orig_head=$(git-rev-parse --verify HEAD) || die "Pulling into a black hole?"
48 git-fetch --update-head-ok --reflog-action=pull "$@" || exit 1
49
50 curr_head=$(git-rev-parse --verify HEAD)
51 if test "$curr_head" != "$orig_head"
52 then
53         # The fetch involved updating the current branch.
54
55         # The working tree and the index file is still based on the
56         # $orig_head commit, but we are merging into $curr_head.
57         # First update the working tree to match $curr_head.
58
59         echo >&2 "Warning: fetch updated the current branch head."
60         echo >&2 "Warning: fast forwarding your working tree from"
61         echo >&2 "Warning: commit $orig_head."
62         git-update-index --refresh 2>/dev/null
63         git-read-tree -u -m "$orig_head" "$curr_head" ||
64                 die 'Cannot fast-forward your working tree.
65 After making sure that you saved anything precious from
66 $ git diff '$orig_head'
67 output, run
68 $ git reset --hard
69 to recover.'
70
71 fi
72
73 merge_head=$(sed -e '/  not-for-merge   /d' \
74         -e 's/  .*//' "$GIT_DIR"/FETCH_HEAD | \
75         tr '\012' ' ')
76
77 case "$merge_head" in
78 '')
79         echo >&2 "No changes."
80         exit 0
81         ;;
82 ?*' '?*)
83         var=`git-repo-config --get pull.octopus`
84         if test -n "$var"
85         then
86                 strategy_default_args="-s $var"
87         fi
88         ;;
89 *)
90         var=`git-repo-config --get pull.twohead`
91         if test -n "$var"
92         then
93                 strategy_default_args="-s $var"
94         fi
95         ;;
96 esac
97
98 case "$strategy_args" in
99 '')
100         strategy_args=$strategy_default_args
101         ;;
102 esac
103
104 merge_name=$(git-fmt-merge-msg <"$GIT_DIR/FETCH_HEAD") || exit
105 git-merge "--reflog-action=pull $*" \
106         $no_summary $no_commit $squash $strategy_args \
107         "$merge_name" HEAD $merge_head