git/git-pull.sh
Santi Béjar d44e71261f pull: support rebased upstream + fetch + pull --rebase
You cannot do a "git pull --rebase" with a rebased upstream, if you have
already run "git fetch".  Try to behave as if the "git fetch" was not run.

In other words, find the fork point of the current branch, where
the tip of upstream branch used to be, and use it as the upstream
parameter of "git rebase".

This patch computes the fork point by walking the reflog to find the first
commit which is an ancestor of the current branch.  Maybe there are
smarter ways to compute it, but this is a straight forward implementation.

Signed-off-by: Santi Béjar <santi@agolina.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2009-07-19 10:29:38 -07:00

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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-stat] [--[no-]commit] [--[no-]squash] [--[no-]ff] [-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
OPTIONS_SPEC=
. 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= diffstat= no_commit= squash= no_ff= log_arg= verbosity=
curr_branch=$(git symbolic-ref -q HEAD)
curr_branch_short=$(echo "$curr_branch" | sed "s|refs/heads/||")
rebase=$(git config --bool branch.$curr_branch_short.rebase)
while :
do
case "$1" in
-q|--quiet)
verbosity="$verbosity -q" ;;
-v|--verbose)
verbosity="$verbosity -v" ;;
-n|--no-stat|--no-summary)
diffstat=--no-stat ;;
--stat|--summary)
diffstat=--stat ;;
--log|--no-log)
log_arg=$1 ;;
--no-c|--no-co|--no-com|--no-comm|--no-commi|--no-commit)
no_commit=--no-commit ;;
--c|--co|--com|--comm|--commi|--commit)
no_commit=--commit ;;
--sq|--squ|--squa|--squas|--squash)
squash=--squash ;;
--no-sq|--no-squ|--no-squa|--no-squas|--no-squash)
squash=--no-squash ;;
--ff)
no_ff=--ff ;;
--no-ff)
no_ff=--no-ff ;;
-s=*|--s=*|--st=*|--str=*|--stra=*|--strat=*|--strate=*|\
--strateg=*|--strategy=*|\
-s|--s|--st|--str|--stra|--strat|--strate|--strateg|--strategy)
case "$#,$1" in
*,*=*)
strategy=`expr "z$1" : 'z-[^=]*=\(.*\)'` ;;
1,*)
usage ;;
*)
strategy="$2"
shift ;;
esac
strategy_args="${strategy_args}-s $strategy "
;;
-r|--r|--re|--reb|--reba|--rebas|--rebase)
rebase=true
;;
--no-r|--no-re|--no-reb|--no-reba|--no-rebas|--no-rebase)
rebase=false
;;
-h|--h|--he|--hel|--help)
usage
;;
*)
# Pass thru anything that may be meant for fetch.
break
;;
esac
shift
done
error_on_no_merge_candidates () {
exec >&2
for opt
do
case "$opt" in
-t|--t|--ta|--tag|--tags)
echo "Fetching tags only, you probably meant:"
echo " git fetch --tags"
exit 1
esac
done
curr_branch=${curr_branch#refs/heads/}
if [ -z "$curr_branch" ]; then
echo "You are not currently on a branch, so I cannot use any"
echo "'branch.<branchname>.merge' in your configuration file."
echo "Please specify which branch you want to merge on the command"
echo "line and try again (e.g. 'git pull <repository> <refspec>')."
echo "See git-pull(1) for details."
else
echo "You asked me to pull without telling me which branch you"
echo "want to merge with, and 'branch.${curr_branch}.merge' in"
echo "your configuration file does not tell me either. Please"
echo "specify which branch you want to merge on the command line and"
echo "try again (e.g. 'git pull <repository> <refspec>')."
echo "See git-pull(1) for details."
echo
echo "If you often merge with the same branch, you may want to"
echo "configure the following variables in your configuration"
echo "file:"
echo
echo " branch.${curr_branch}.remote = <nickname>"
echo " branch.${curr_branch}.merge = <remote-ref>"
echo " remote.<nickname>.url = <url>"
echo " remote.<nickname>.fetch = <refspec>"
echo
echo "See git-config(1) for details."
fi
exit 1
}
test true = "$rebase" && {
git update-index --ignore-submodules --refresh &&
git diff-files --ignore-submodules --quiet &&
git diff-index --ignore-submodules --cached --quiet HEAD -- ||
die "refusing to pull with rebase: your working tree is not up-to-date"
oldremoteref= &&
. git-parse-remote &&
remoteref="$(get_remote_merge_branch "$@" 2>/dev/null)" &&
oldremoteref="$(git rev-parse -q --verify "$remoteref")" &&
for reflog in $(git rev-list -g $remoteref 2>/dev/null)
do
if test "$reflog" = "$(git merge-base $reflog $curr_branch)"
then
oldremoteref="$reflog"
break
fi
done
}
orig_head=$(git rev-parse -q --verify HEAD)
git fetch $verbosity --update-head-ok "$@" || exit 1
curr_head=$(git rev-parse -q --verify HEAD)
if test -n "$orig_head" && 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 $orig_head."
git update-index -q --refresh
git read-tree -u -m "$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
'')
case $? in
0) error_on_no_merge_candidates "$@";;
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 $?;;
esac
;;
?*' '?*)
if test -z "$orig_head"
then
die "Cannot merge multiple branches into empty head"
fi
if test true = "$rebase"
then
die "Cannot rebase onto multiple branches"
fi
;;
esac
if test -z "$orig_head"
then
git update-ref -m "initial pull" HEAD $merge_head "$curr_head" &&
git read-tree --reset -u HEAD || exit 1
exit
fi
merge_name=$(git fmt-merge-msg $log_arg <"$GIT_DIR/FETCH_HEAD") || exit
test true = "$rebase" &&
exec git-rebase $diffstat $strategy_args --onto $merge_head \
${oldremoteref:-$merge_head}
exec git-merge $diffstat $no_commit $squash $no_ff $log_arg $strategy_args \
"$merge_name" HEAD $merge_head $verbosity