git/git-pull.sh
Jeff King a74b1706c8 git-pull: disallow implicit merging to detached HEAD
Instead, we complain to the user and suggest that they explicitly
specify the remote and branch. We depend on the exit status of
git-symbolic-ref, so let's go ahead and document that.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <junkio@cox.net>
2007-01-15 15:37:22 -08:00

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#!/bin/sh
#
# Copyright (c) 2005 Junio C Hamano
#
# Fetch one or more remote refs and merge it/them into the current HEAD.
USAGE='[-n | --no-summary] [--no-commit] [-s strategy]... [<fetch-options>] <repo> <head>...'
LONG_USAGE='Fetch one or more remote refs and merge it/them into the current HEAD.'
SUBDIRECTORY_OK=Yes
. git-sh-setup
set_reflog_action "pull $*"
require_work_tree
cd_to_toplevel
test -z "$(git ls-files -u)" ||
die "You are in the middle of a conflicted merge."
strategy_args= no_summary= no_commit= squash=
while case "$#,$1" in 0) break ;; *,-*) ;; *) break ;; esac
do
case "$1" in
-n|--n|--no|--no-|--no-s|--no-su|--no-sum|--no-summ|\
--no-summa|--no-summar|--no-summary)
no_summary=-n ;;
--no-c|--no-co|--no-com|--no-comm|--no-commi|--no-commit)
no_commit=--no-commit ;;
--sq|--squ|--squa|--squas|--squash)
squash=--squash ;;
-s=*|--s=*|--st=*|--str=*|--stra=*|--strat=*|--strate=*|\
--strateg=*|--strategy=*|\
-s|--s|--st|--str|--stra|--strat|--strate|--strateg|--strategy)
case "$#,$1" in
*,*=*)
strategy=`expr "z$1" : 'z-[^=]*=\(.*\)'` ;;
1,*)
usage ;;
*)
strategy="$2"
shift ;;
esac
strategy_args="${strategy_args}-s $strategy "
;;
-h|--h|--he|--hel|--help)
usage
;;
-*)
# Pass thru anything that is meant for fetch.
break
;;
esac
shift
done
orig_head=$(git-rev-parse --verify HEAD 2>/dev/null)
git-fetch --update-head-ok "$@" || exit 1
curr_head=$(git-rev-parse --verify HEAD 2>/dev/null)
if test "$curr_head" != "$orig_head"
then
# The fetch involved updating the current branch.
# The working tree and the index file is still based on the
# $orig_head commit, but we are merging into $curr_head.
# First update the working tree to match $curr_head.
echo >&2 "Warning: fetch updated the current branch head."
echo >&2 "Warning: fast forwarding your working tree from"
echo >&2 "Warning: commit $orig_head."
git-update-index --refresh 2>/dev/null
git-read-tree -u -m "$orig_head" "$curr_head" ||
die 'Cannot fast-forward your working tree.
After making sure that you saved anything precious from
$ git diff '$orig_head'
output, run
$ git reset --hard
to recover.'
fi
merge_head=$(sed -e '/ not-for-merge /d' \
-e 's/ .*//' "$GIT_DIR"/FETCH_HEAD | \
tr '\012' ' ')
case "$merge_head" in
'')
curr_branch=$(git-symbolic-ref -q HEAD)
case $? in
0) ;;
1) echo >&2 "You are not currently on a branch; you must explicitly"
echo >&2 "specify which branch you wish to merge:"
echo >&2 " git pull <remote> <branch>"
exit 1;;
*) exit $?;;
esac
curr_branch=${curr_branch#refs/heads/}
echo >&2 "Warning: No merge candidate found because value of config option
\"branch.${curr_branch}.merge\" does not match any remote branch fetched."
echo >&2 "No changes."
exit 0
;;
?*' '?*)
if test -z "$orig_head"
then
echo >&2 "Cannot merge multiple branches into empty head"
exit 1
fi
;;
esac
if test -z "$orig_head"
then
git-update-ref -m "initial pull" HEAD $merge_head "" &&
git-read-tree --reset -u HEAD || exit 1
exit
fi
merge_name=$(git-fmt-merge-msg <"$GIT_DIR/FETCH_HEAD") || exit
exec git-merge $no_summary $no_commit $squash $strategy_args \
"$merge_name" HEAD $merge_head