Merge branch 'pt/pull-builtin'

Reimplement 'git pull' in C.

* pt/pull-builtin:
  pull: remove redirection to git-pull.sh
  pull --rebase: error on no merge candidate cases
  pull --rebase: exit early when the working directory is dirty
  pull: configure --rebase via branch.<name>.rebase or pull.rebase
  pull: teach git pull about --rebase
  pull: set reflog message
  pull: implement pulling into an unborn branch
  pull: fast-forward working tree if head is updated
  pull: check if in unresolved merge state
  pull: support pull.ff config
  pull: error on no merge candidates
  pull: pass git-fetch's options to git-fetch
  pull: pass git-merge's options to git-merge
  pull: pass verbosity, --progress flags to fetch and merge
  pull: implement fetch + merge
  pull: implement skeletal builtin pull
  argv-array: implement argv_array_pushv()
  parse-options-cb: implement parse_opt_passthru_argv()
  parse-options-cb: implement parse_opt_passthru()

1 files changed, 381 insertions, 0 deletions

diff --git a/contrib/examples/git-pull.sh b/contrib/examples/git-pull.sh
new file mode 100755
index 0000000000..a814bf61aa
--- /dev/null
+++ b/contrib/examples/git-pull.sh
@@ -0,0 +1,381 @@
+#!/bin/sh
+#
+# Copyright (c) 2005 Junio C Hamano
+#
+# Fetch one or more remote refs and merge it/them into the current HEAD.
+
+SUBDIRECTORY_OK=Yes
+OPTIONS_KEEPDASHDASH=
+OPTIONS_STUCKLONG=Yes
+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 $# -gt 0 && args="$*"
+. git-sh-setup
+. git-sh-i18n
+set_reflog_action "pull${args+ $args}"
+require_work_tree_exists
+cd_to_toplevel
+
+
+die_conflict () {
+    git diff-index --cached --name-status -r --ignore-submodules HEAD --
+    if [ $(git config --bool --get advice.resolveConflict || echo true) = "true" ]; then
+	die "$(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.")"
+    fi
+}
+
+die_merge () {
+    if [ $(git config --bool --get advice.resolveConflict || echo true) = "true" ]; then
+	die "$(gettext "You have not concluded your merge (MERGE_HEAD exists).
+Please, commit your changes before you can merge.")"
+    else
+	die "$(gettext "You have not concluded your merge (MERGE_HEAD exists).")"
+    fi
+}
+
+test -z "$(git ls-files -u)" || die_conflict
+test -f "$GIT_DIR/MERGE_HEAD" && die_merge
+
+bool_or_string_config () {
+	git config --bool "$1" 2>/dev/null || git config "$1"
+}
+
+strategy_args= diffstat= no_commit= squash= no_ff= ff_only=
+log_arg= verbosity= progress= recurse_submodules= verify_signatures=
+merge_args= edit= rebase_args= all= append= upload_pack= force= tags= prune=
+keep= depth= unshallow= update_shallow= refmap=
+curr_branch=$(git symbolic-ref -q HEAD)
+curr_branch_short="${curr_branch#refs/heads/}"
+rebase=$(bool_or_string_config branch.$curr_branch_short.rebase)
+if test -z "$rebase"
+then
+	rebase=$(bool_or_string_config pull.rebase)
+fi
+
+# Setup default fast-forward options via `pull.ff`
+pull_ff=$(bool_or_string_config pull.ff)
+case "$pull_ff" in
+true)
+	no_ff=--ff
+	;;
+false)
+	no_ff=--no-ff
+	;;
+only)
+	ff_only=--ff-only
+	;;
+esac
+
+
+dry_run=
+while :
+do
+	case "$1" in
+	-q|--quiet)
+		verbosity="$verbosity -q" ;;
+	-v|--verbose)
+		verbosity="$verbosity -v" ;;
+	--progress)
+		progress=--progress ;;
+	--no-progress)
+		progress=--no-progress ;;
+	-n|--no-stat|--no-summary)
+		diffstat=--no-stat ;;
+	--stat|--summary)
+		diffstat=--stat ;;
+	--log|--log=*|--no-log)
+		log_arg="$1" ;;
+	--no-commit)
+		no_commit=--no-commit ;;
+	--commit)
+		no_commit=--commit ;;
+	-e|--edit)
+		edit=--edit ;;
+	--no-edit)
+		edit=--no-edit ;;
+	--squash)
+		squash=--squash ;;
+	--no-squash)
+		squash=--no-squash ;;
+	--ff)
+		no_ff=--ff ;;
+	--no-ff)
+		no_ff=--no-ff ;;
+	--ff-only)
+		ff_only=--ff-only ;;
+	-s*|--strategy=*)
+		strategy_args="$strategy_args $1"
+		;;
+	-X*|--strategy-option=*)
+		merge_args="$merge_args $(git rev-parse --sq-quote "$1")"
+		;;
+	-r*|--rebase=*)
+		rebase="${1#*=}"
+		;;
+	--rebase)
+		rebase=true
+		;;
+	--no-rebase)
+		rebase=false
+		;;
+	--recurse-submodules)
+		recurse_submodules=--recurse-submodules
+		;;
+	--recurse-submodules=*)
+		recurse_submodules="$1"
+		;;
+	--no-recurse-submodules)
+		recurse_submodules=--no-recurse-submodules
+		;;
+	--verify-signatures)
+		verify_signatures=--verify-signatures
+		;;
+	--no-verify-signatures)
+		verify_signatures=--no-verify-signatures
+		;;
+	--gpg-sign|-S)
+		gpg_sign_args=-S
+		;;
+	--gpg-sign=*)
+		gpg_sign_args=$(git rev-parse --sq-quote "-S${1#--gpg-sign=}")
+		;;
+	-S*)
+		gpg_sign_args=$(git rev-parse --sq-quote "$1")
+		;;
+	--dry-run)
+		dry_run=--dry-run
+		;;
+	--all|--no-all)
+		all=$1 ;;
+	-a|--append|--no-append)
+		append=$1 ;;
+	--upload-pack=*|--no-upload-pack)
+		upload_pack=$1 ;;
+	-f|--force|--no-force)
+		force="$force $1" ;;
+	-t|--tags|--no-tags)
+		tags=$1 ;;
+	-p|--prune|--no-prune)
+		prune=$1 ;;
+	-k|--keep|--no-keep)
+		keep=$1 ;;
+	--depth=*|--no-depth)
+		depth=$1 ;;
+	--unshallow|--no-unshallow)
+		unshallow=$1 ;;
+	--update-shallow|--no-update-shallow)
+		update_shallow=$1 ;;
+	--refmap=*|--no-refmap)
+		refmap=$1 ;;
+	-h|--help-all)
+		usage
+		;;
+	--)
+		shift
+		break
+		;;
+	*)
+		usage
+		;;
+	esac
+	shift
+done
+
+case "$rebase" in
+preserve)
+	rebase=true
+	rebase_args=--preserve-merges
+	;;
+true|false|'')
+	;;
+*)
+	echo "Invalid value for --rebase, should be true, false, or preserve"
+	usage
+	exit 1
+	;;
+esac
+
+error_on_no_merge_candidates () {
+	exec >&2
+
+	if test true = "$rebase"
+	then
+		op_type=rebase
+		op_prep=against
+	else
+		op_type=merge
+		op_prep=with
+	fi
+
+	upstream=$(git config "branch.$curr_branch_short.merge")
+	remote=$(git config "branch.$curr_branch_short.remote")
+
+	if [ $# -gt 1 ]; then
+		if [ "$rebase" = true ]; then
+			printf "There is no candidate for rebasing against "
+		else
+			printf "There are no candidates for merging "
+		fi
+		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 [ $# -gt 0 ] && [ "$1" != "$remote" ]; then
+		echo "You asked to pull from the remote '$1', but did not specify"
+		echo "a branch. Because this is not the default configured remote"
+		echo "for your current branch, you must specify a branch on the command line."
+	elif [ -z "$curr_branch" -o -z "$upstream" ]; then
+		. 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."
+	fi
+	exit 1
+}
+
+test true = "$rebase" && {
+	if ! git rev-parse -q --verify HEAD >/dev/null
+	then
+		# On an unborn branch
+		if test -f "$(git rev-parse --git-path index)"
+		then
+			die "$(gettext "updating an unborn branch with changes added to the index")"
+		fi
+	else
+		require_clean_work_tree "pull with rebase" "Please commit or stash them."
+	fi
+	oldremoteref= &&
+	test -n "$curr_branch" &&
+	. git-parse-remote &&
+	remoteref="$(get_remote_merge_branch "$@" 2>/dev/null)" &&
+	oldremoteref=$(git merge-base --fork-point "$remoteref" $curr_branch 2>/dev/null)
+}
+orig_head=$(git rev-parse -q --verify HEAD)
+git fetch $verbosity $progress $dry_run $recurse_submodules $all $append \
+$upload_pack $force $tags $prune $keep $depth $unshallow $update_shallow \
+$refmap --update-head-ok "$@" || exit 1
+test -z "$dry_run" || exit 0
+
+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 $curr_head.
+
+	eval_gettextln "Warning: fetch updated the current branch head.
+Warning: fast-forwarding your working tree from
+Warning: commit \$orig_head." >&2
+	git update-index -q --refresh
+	git read-tree -u -m "$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.")"
+
+fi
+
+merge_head=$(sed -e '/	not-for-merge	/d' \
+	-e 's/	.*//' "$GIT_DIR"/FETCH_HEAD | \
+	tr '\012' ' ')
+
+case "$merge_head" in
+'')
+	error_on_no_merge_candidates "$@"
+	;;
+?*' '?*)
+	if test -z "$orig_head"
+	then
+		die "$(gettext "Cannot merge multiple branches into empty head")"
+	fi
+	if test true = "$rebase"
+	then
+		die "$(gettext "Cannot rebase onto multiple branches")"
+	fi
+	;;
+esac
+
+# Pulling into unborn branch: a shorthand for branching off
+# FETCH_HEAD, for lazy typers.
+if test -z "$orig_head"
+then
+	# 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.
+	empty_tree=4b825dc642cb6eb9a060e54bf8d69288fbee4904
+	git read-tree -m -u $empty_tree $merge_head &&
+	git update-ref -m "initial pull" HEAD $merge_head "$curr_head"
+	exit
+fi
+
+if test true = "$rebase"
+then
+	o=$(git show-branch --merge-base $curr_branch $merge_head $oldremoteref)
+	if test "$oldremoteref" = "$o"
+	then
+		unset oldremoteref
+	fi
+fi
+
+case "$rebase" in
+true)
+	eval="git-rebase $diffstat $strategy_args $merge_args $rebase_args $verbosity"
+	eval="$eval $gpg_sign_args"
+	eval="$eval --onto $merge_head ${oldremoteref:-$merge_head}"
+	;;
+*)
+	eval="git-merge $diffstat $no_commit $verify_signatures $edit $squash $no_ff $ff_only"
+	eval="$eval $log_arg $strategy_args $merge_args $verbosity $progress"
+	eval="$eval $gpg_sign_args"
+	eval="$eval FETCH_HEAD"
+	;;
+esac
+eval "exec $eval"