#!/bin/sh
#
# Copyright (c) 2005 Junio C Hamano
#
# Fetch one or more remote refs and merge it/them into the current HEAD.

setvar SUBDIRECTORY_OK = 'Yes'
setvar OPTIONS_KEEPDASHDASH = ''
setvar OPTIONS_STUCKLONG = 'Yes'
setvar OPTIONS_SPEC = ""\
git pull [options] [<repository> [<refspec>...]]

Fetch one or more remote refs and integrate it/them with the current HEAD.
--
v,verbose                  be more verbose
q,quiet                    be more quiet
progress                   force progress reporting

  Options related to merging
r,rebase?false|true|preserve incorporate changes by rebasing rather than merging
n!                         do not show a diffstat at the end of the merge
stat                       show a diffstat at the end of the merge
summary                    (synonym to --stat)
log?n                      add (at most <n>) entries from shortlog to merge commit message
squash                     create a single commit instead of doing a merge
commit                     perform a commit if the merge succeeds (default)
e,edit                       edit message before committing
ff                         allow fast-forward
ff-only!                   abort if fast-forward is not possible
verify-signatures          verify that the named commit has a valid GPG signature
s,strategy=strategy        merge strategy to use
X,strategy-option=option   option for selected merge strategy
S,gpg-sign?key-id          GPG sign commit

  Options related to fetching
all                        fetch from all remotes
a,append                   append to .git/FETCH_HEAD instead of overwriting
upload-pack=path           path to upload pack on remote end
f,force                    force overwrite of local branch
t,tags                     fetch all tags and associated objects
p,prune                    prune remote-tracking branches no longer on remote
recurse-submodules?on-demand control recursive fetching of submodules
dry-run                    dry run
k,keep                     keep downloaded pack
depth=depth                deepen history of shallow clone
unshallow                  convert to a complete repository
update-shallow             accept refs that update .git/shallow
refmap=refmap              specify fetch refmap
""
test $Argc -gt 0 && setvar args = ""$[join(ARGV)]""
source git-sh-setup
source git-sh-i18n
set_reflog_action "pull${args+ $args}"
require_work_tree_exists
cd_to_toplevel


proc die_conflict {
    git diff-index --cached --name-status -r --ignore-submodules HEAD --
    if test $(git config --bool --get advice.resolveConflict || echo true) = "true" {
	die $(gettext "Pull is not possible because you have unmerged files.
Please, fix them up in the work tree, and then use 'git add/rm <file>'
as appropriate to mark resolution and make a commit.")
    } else {
	die $(gettext "Pull is not possible because you have unmerged files.")
    }
}

proc die_merge {
    if test $(git config --bool --get advice.resolveConflict || echo true) = "true" {
	die $(gettext "You have not concluded your merge (MERGE_HEAD exists).
Please, commit your changes before merging.")
    } else {
	die $(gettext "You have not concluded your merge (MERGE_HEAD exists).")
    }
}

test -z $(git ls-files -u) || die_conflict
test -f "$GIT_DIR/MERGE_HEAD" && die_merge

proc bool_or_string_config {
	git config --bool $1 2>/dev/null || git config $1
}

setvar strategy_args = '', diffstat = '', no_commit = '', squash = '', no_ff = '', ff_only = ''
setvar log_arg = '', verbosity = '', progress = '', recurse_submodules = '', verify_signatures = ''
setvar merge_args = '', edit = '', rebase_args = '', all = '', append = '', upload_pack = '', force = '', tags = '', prune = ''
setvar keep = '', depth = '', unshallow = '', update_shallow = '', refmap = ''
setvar curr_branch = $(git symbolic-ref -q HEAD)
setvar curr_branch_short = "${curr_branch#refs/heads/}"
setvar rebase = $(bool_or_string_config branch.$curr_branch_short.rebase)
if test -z $rebase
{
	setvar rebase = $(bool_or_string_config pull.rebase)
}

# Setup default fast-forward options via `pull.ff`
setvar pull_ff = $(bool_or_string_config pull.ff)
case (pull_ff) {
true {
	setvar no_ff = '--ff'
	}
false {
	setvar no_ff = '--no-ff'
	}
only {
	setvar ff_only = '--ff-only'
	}
}


setvar dry_run = ''
while :
{
	case (1) {
	-q|--quiet {
		setvar verbosity = ""$verbosity -q"" }
	-v|--verbose {
		setvar verbosity = ""$verbosity -v"" }
	--progress {
		setvar progress = '--progress' }
	--no-progress {
		setvar progress = '--no-progress' }
	-n|--no-stat|--no-summary {
		setvar diffstat = '--no-stat' }
	--stat|--summary {
		setvar diffstat = '--stat' }
	--log|--log=*|--no-log {
		setvar log_arg = "$1" }
	--no-commit {
		setvar no_commit = '--no-commit' }
	--commit {
		setvar no_commit = '--commit' }
	-e|--edit {
		setvar edit = '--edit' }
	--no-edit {
		setvar edit = '--no-edit' }
	--squash {
		setvar squash = '--squash' }
	--no-squash {
		setvar squash = '--no-squash' }
	--ff {
		setvar no_ff = '--ff' }
	--no-ff {
		setvar no_ff = '--no-ff' }
	--ff-only {
		setvar ff_only = '--ff-only' }
	-s*|--strategy=* {
		setvar strategy_args = ""$strategy_args $1""
		}
	-X*|--strategy-option=* {
		setvar merge_args = ""$merge_args $(git rev-parse --sq-quote "$1")""
		}
	-r*|--rebase=* {
		setvar rebase = "${1#*=}"
		}
	--rebase {
		setvar rebase = 'true'
		}
	--no-rebase {
		setvar rebase = 'false'
		}
	--recurse-submodules {
		setvar recurse_submodules = '--recurse-submodules'
		}
	--recurse-submodules=* {
		setvar recurse_submodules = "$1"
		}
	--no-recurse-submodules {
		setvar recurse_submodules = '--no-recurse-submodules'
		}
	--verify-signatures {
		setvar verify_signatures = '--verify-signatures'
		}
	--no-verify-signatures {
		setvar verify_signatures = '--no-verify-signatures'
		}
	--gpg-sign|-S {
		setvar gpg_sign_args = '-S'
		}
	--gpg-sign=* {
		setvar gpg_sign_args = $(git rev-parse --sq-quote "-S${1#--gpg-sign=}")
		}
	-S* {
		setvar gpg_sign_args = $(git rev-parse --sq-quote "$1")
		}
	--dry-run {
		setvar dry_run = '--dry-run'
		}
	--all|--no-all {
		setvar all = "$1" }
	-a|--append|--no-append {
		setvar append = "$1" }
	--upload-pack=*|--no-upload-pack {
		setvar upload_pack = "$1" }
	-f|--force|--no-force {
		setvar force = ""$force $1"" }
	-t|--tags|--no-tags {
		setvar tags = "$1" }
	-p|--prune|--no-prune {
		setvar prune = "$1" }
	-k|--keep|--no-keep {
		setvar keep = "$1" }
	--depth=*|--no-depth {
		setvar depth = "$1" }
	--unshallow|--no-unshallow {
		setvar unshallow = "$1" }
	--update-shallow|--no-update-shallow {
		setvar update_shallow = "$1" }
	--refmap=*|--no-refmap {
		setvar refmap = "$1" }
	-h|--help-all {
		usage
		}
	-- {
		shift
		break
		}
	* {
		usage
		}
	}
	shift
}

case (rebase) {
preserve {
	setvar rebase = 'true'
	setvar rebase_args = '--preserve-merges'
	}
true|false|'' {
	}
* {
	echo "Invalid value for --rebase, should be true, false, or preserve"
	usage
	exit 1
	}
}

proc error_on_no_merge_candidates {
	exec >&2

	if test true = $rebase
	{
		setvar op_type = 'rebase'
		setvar op_prep = 'against'
	} else {
		setvar op_type = 'merge'
		setvar op_prep = 'with'
	}

	setvar upstream = $(git config "branch.$curr_branch_short.merge")
	setvar remote = $(git config "branch.$curr_branch_short.remote")

	if test $Argc -gt 1 {
		if test $rebase = true {
			printf "There is no candidate for rebasing against "
		} else {
			printf "There are no candidates for merging "
		}
		echo "among the refs that you just fetched."
		echo "Generally this means that you provided a wildcard refspec which had no"
		echo "matches on the remote end."
	} elif test $Argc -gt 0 && test $1 != $remote {
		echo "You asked to pull from the remote '$1', but did not specify"
		echo "a branch. Because this is not the default configured remote"
		echo "for your current branch, you must specify a branch on the command line."
	} elif test -z $curr_branch -o -z $upstream {
		source git-parse-remote
		error_on_missing_default_upstream "pull" $op_type $op_prep \
			"git pull <remote> <branch>"
	} else {
		echo "Your configuration specifies to $op_type $op_prep the ref '${upstream#refs/heads/}'"
		echo "from the remote, but no such ref was fetched."
	}
	exit 1
}

test true = $rebase && do {
	if ! git rev-parse -q --verify HEAD >/dev/null
	{
		# On an unborn branch
		if test -f $(git rev-parse --git-path index)
		{
			die $(gettext "updating an unborn branch with changes added to the index")
		}
	} else {
		require_clean_work_tree "pull with rebase" "Please commit or stash them."
	}
	setvar oldremoteref = '' &&
	test -n $curr_branch &&
	source git-parse-remote &&
	setvar remoteref = "$(get_remote_merge_branch "$@" 2>/dev/null)" &&
	setvar oldremoteref = $(git merge-base --fork-point "$remoteref" $curr_branch 2>/dev/null)
}
setvar orig_head = $(git rev-parse -q --verify HEAD)
git fetch $verbosity $progress $dry_run $recurse_submodules $all $append \
${upload_pack:+"$upload_pack"} $force $tags $prune $keep $depth $unshallow $update_shallow \
$refmap --update-head-ok @ARGV || exit 1
test -z $dry_run || exit 0

setvar curr_head = $(git rev-parse -q --verify HEAD)
if test -n $orig_head && test $curr_head != $orig_head
{
	# 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.

	eval_gettextln "Warning: fetch updated the current branch head.
Warning: fast-forwarding your working tree from
Warning: commit \$orig_head." >&2
	git update-index -q --refresh
	git read-tree -u -m $orig_head $curr_head ||
		die $(eval_gettext "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.")

}

setvar merge_head = $(sed -e '/	not-for-merge	/d' \
	-e 's/	.*//' "$GIT_DIR"/FETCH_HEAD | \
	tr '\012' ' ')

case (merge_head) {
'' {
	error_on_no_merge_candidates @ARGV
	}
?*' '?* {
	if test -z $orig_head
	{
		die $(gettext "Cannot merge multiple branches into empty head")
	}
	if test true = $rebase
	{
		die $(gettext "Cannot rebase onto multiple branches")
	}
	}
}

# Pulling into unborn branch: a shorthand for branching off
# FETCH_HEAD, for lazy typers.
if test -z $orig_head
{
	# Two-way merge: we claim the index is based on an empty tree,
	# and try to fast-forward to HEAD.  This ensures we will not
	# lose index/worktree changes that the user already made on
	# the unborn branch.
	setvar empty_tree = '4b825dc642cb6eb9a060e54bf8d69288fbee4904'
	git read-tree -m -u $empty_tree $merge_head &&
	git update-ref -m "initial pull" HEAD $merge_head $curr_head
	exit
}

if test true = $rebase
{
	setvar o = $(git show-branch --merge-base $curr_branch $merge_head $oldremoteref)
	if test $oldremoteref = $o
	{
		unset oldremoteref
	}
}

case (rebase) {
true {
	setvar eval = ""git-rebase $diffstat $strategy_args $merge_args $rebase_args $verbosity""
	setvar eval = ""$eval $gpg_sign_args""
	setvar eval = ""$eval --onto $merge_head ${oldremoteref:-$merge_head}""
	}
* {
	setvar eval = ""git-merge $diffstat $no_commit $verify_signatures $edit $squash $no_ff $ff_only""
	setvar eval = ""$eval $log_arg $strategy_args $merge_args $verbosity $progress""
	setvar eval = ""$eval $gpg_sign_args""
	setvar eval = ""$eval FETCH_HEAD""
	}
}
eval "exec $eval"