Squashed 'third_party/git/' content from commit cb71568594

git-subtree-dir: third_party/git
git-subtree-split: cb715685942260375e1eb8153b0768a376e4ece7

1 files changed, 463 insertions, 0 deletions

diff --git a/git-mergetool--lib.sh b/git-mergetool--lib.sh
new file mode 100644
index 000000000000..204a5acd66f5
--- /dev/null
+++ b/git-mergetool--lib.sh
@@ -0,0 +1,463 @@
+# git-mergetool--lib is a shell library for common merge tool functions
+
+: ${MERGE_TOOLS_DIR=$(git --exec-path)/mergetools}
+
+IFS='
+'
+
+mode_ok () {
+	if diff_mode
+	then
+		can_diff
+	elif merge_mode
+	then
+		can_merge
+	else
+		false
+	fi
+}
+
+is_available () {
+	merge_tool_path=$(translate_merge_tool_path "$1") &&
+	type "$merge_tool_path" >/dev/null 2>&1
+}
+
+list_config_tools () {
+	section=$1
+	line_prefix=${2:-}
+
+	git config --get-regexp $section'\..*\.cmd' |
+	while read -r key value
+	do
+		toolname=${key#$section.}
+		toolname=${toolname%.cmd}
+
+		printf "%s%s\n" "$line_prefix" "$toolname"
+	done
+}
+
+show_tool_names () {
+	condition=${1:-true} per_line_prefix=${2:-} preamble=${3:-}
+	not_found_msg=${4:-}
+	extra_content=${5:-}
+
+	shown_any=
+	( cd "$MERGE_TOOLS_DIR" && ls ) | {
+		while read toolname
+		do
+			if setup_tool "$toolname" 2>/dev/null &&
+				(eval "$condition" "$toolname")
+			then
+				if test -n "$preamble"
+				then
+					printf "%s\n" "$preamble"
+					preamble=
+				fi
+				shown_any=yes
+				printf "%s%s\n" "$per_line_prefix" "$toolname"
+			fi
+		done
+
+		if test -n "$extra_content"
+		then
+			if test -n "$preamble"
+			then
+				# Note: no '\n' here since we don't want a
+				# blank line if there is no initial content.
+				printf "%s" "$preamble"
+				preamble=
+			fi
+			shown_any=yes
+			printf "\n%s\n" "$extra_content"
+		fi
+
+		if test -n "$preamble" && test -n "$not_found_msg"
+		then
+			printf "%s\n" "$not_found_msg"
+		fi
+
+		test -n "$shown_any"
+	}
+}
+
+diff_mode () {
+	test "$TOOL_MODE" = diff
+}
+
+merge_mode () {
+	test "$TOOL_MODE" = merge
+}
+
+gui_mode () {
+	test "$GIT_MERGETOOL_GUI" = true
+}
+
+translate_merge_tool_path () {
+	echo "$1"
+}
+
+check_unchanged () {
+	if test "$MERGED" -nt "$BACKUP"
+	then
+		return 0
+	else
+		while true
+		do
+			echo "$MERGED seems unchanged."
+			printf "Was the merge successful [y/n]? "
+			read answer || return 1
+			case "$answer" in
+			y*|Y*) return 0 ;;
+			n*|N*) return 1 ;;
+			esac
+		done
+	fi
+}
+
+valid_tool () {
+	setup_tool "$1" && return 0
+	cmd=$(get_merge_tool_cmd "$1")
+	test -n "$cmd"
+}
+
+setup_user_tool () {
+	merge_tool_cmd=$(get_merge_tool_cmd "$tool")
+	test -n "$merge_tool_cmd" || return 1
+
+	diff_cmd () {
+		( eval $merge_tool_cmd )
+	}
+
+	merge_cmd () {
+		( eval $merge_tool_cmd )
+	}
+}
+
+setup_tool () {
+	tool="$1"
+
+	# Fallback definitions, to be overridden by tools.
+	can_merge () {
+		return 0
+	}
+
+	can_diff () {
+		return 0
+	}
+
+	diff_cmd () {
+		return 1
+	}
+
+	merge_cmd () {
+		return 1
+	}
+
+	translate_merge_tool_path () {
+		echo "$1"
+	}
+
+	# Most tools' exit codes cannot be trusted, so By default we ignore
+	# their exit code and check the merged file's modification time in
+	# check_unchanged() to determine whether or not the merge was
+	# successful.  The return value from run_merge_cmd, by default, is
+	# determined by check_unchanged().
+	#
+	# When a tool's exit code can be trusted then the return value from
+	# run_merge_cmd is simply the tool's exit code, and check_unchanged()
+	# is not called.
+	#
+	# The return value of exit_code_trustable() tells us whether or not we
+	# can trust the tool's exit code.
+	#
+	# User-defined and built-in tools default to false.
+	# Built-in tools advertise that their exit code is trustable by
+	# redefining exit_code_trustable() to true.
+
+	exit_code_trustable () {
+		false
+	}
+
+
+	if ! test -f "$MERGE_TOOLS_DIR/$tool"
+	then
+		setup_user_tool
+		return $?
+	fi
+
+	# Load the redefined functions
+	. "$MERGE_TOOLS_DIR/$tool"
+	# Now let the user override the default command for the tool.  If
+	# they have not done so then this will return 1 which we ignore.
+	setup_user_tool
+
+	if merge_mode && ! can_merge
+	then
+		echo "error: '$tool' can not be used to resolve merges" >&2
+		return 1
+	elif diff_mode && ! can_diff
+	then
+		echo "error: '$tool' can only be used to resolve merges" >&2
+		return 1
+	fi
+	return 0
+}
+
+get_merge_tool_cmd () {
+	merge_tool="$1"
+	if diff_mode
+	then
+		git config "difftool.$merge_tool.cmd" ||
+		git config "mergetool.$merge_tool.cmd"
+	else
+		git config "mergetool.$merge_tool.cmd"
+	fi
+}
+
+trust_exit_code () {
+	if git config --bool "mergetool.$1.trustExitCode"
+	then
+		:; # OK
+	elif exit_code_trustable
+	then
+		echo true
+	else
+		echo false
+	fi
+}
+
+
+# Entry point for running tools
+run_merge_tool () {
+	# If GIT_PREFIX is empty then we cannot use it in tools
+	# that expect to be able to chdir() to its value.
+	GIT_PREFIX=${GIT_PREFIX:-.}
+	export GIT_PREFIX
+
+	merge_tool_path=$(get_merge_tool_path "$1") || exit
+	base_present="$2"
+
+	# Bring tool-specific functions into scope
+	setup_tool "$1" || return 1
+
+	if merge_mode
+	then
+		run_merge_cmd "$1"
+	else
+		run_diff_cmd "$1"
+	fi
+}
+
+# Run a either a configured or built-in diff tool
+run_diff_cmd () {
+	diff_cmd "$1"
+}
+
+# Run a either a configured or built-in merge tool
+run_merge_cmd () {
+	mergetool_trust_exit_code=$(trust_exit_code "$1")
+	if test "$mergetool_trust_exit_code" = "true"
+	then
+		merge_cmd "$1"
+	else
+		touch "$BACKUP"
+		merge_cmd "$1"
+		check_unchanged
+	fi
+}
+
+list_merge_tool_candidates () {
+	if merge_mode
+	then
+		tools="tortoisemerge"
+	else
+		tools="kompare"
+	fi
+	if test -n "$DISPLAY"
+	then
+		if test -n "$GNOME_DESKTOP_SESSION_ID"
+		then
+			tools="meld opendiff kdiff3 tkdiff xxdiff $tools"
+		else
+			tools="opendiff kdiff3 tkdiff xxdiff meld $tools"
+		fi
+		tools="$tools gvimdiff diffuse diffmerge ecmerge"
+		tools="$tools p4merge araxis bc codecompare"
+		tools="$tools smerge"
+	fi
+	case "${VISUAL:-$EDITOR}" in
+	*vim*)
+		tools="$tools vimdiff emerge"
+		;;
+	*)
+		tools="$tools emerge vimdiff"
+		;;
+	esac
+}
+
+show_tool_help () {
+	tool_opt="'git ${TOOL_MODE}tool --tool=<tool>'"
+
+	tab='	'
+	LF='
+'
+	any_shown=no
+
+	cmd_name=${TOOL_MODE}tool
+	config_tools=$({
+		diff_mode && list_config_tools difftool "$tab$tab"
+		list_config_tools mergetool "$tab$tab"
+	} | sort)
+	extra_content=
+	if test -n "$config_tools"
+	then
+		extra_content="${tab}user-defined:${LF}$config_tools"
+	fi
+
+	show_tool_names 'mode_ok && is_available' "$tab$tab" \
+		"$tool_opt may be set to one of the following:" \
+		"No suitable tool for 'git $cmd_name --tool=<tool>' found." \
+		"$extra_content" &&
+		any_shown=yes
+
+	show_tool_names 'mode_ok && ! is_available' "$tab$tab" \
+		"${LF}The following tools are valid, but not currently available:" &&
+		any_shown=yes
+
+	if test "$any_shown" = yes
+	then
+		echo
+		echo "Some of the tools listed above only work in a windowed"
+		echo "environment. If run in a terminal-only session, they will fail."
+	fi
+	exit 0
+}
+
+guess_merge_tool () {
+	list_merge_tool_candidates
+	cat >&2 <<-EOF
+
+	This message is displayed because '$TOOL_MODE.tool' is not configured.
+	See 'git ${TOOL_MODE}tool --tool-help' or 'git help config' for more details.
+	'git ${TOOL_MODE}tool' will now attempt to use one of the following tools:
+	$tools
+	EOF
+
+	# Loop over each candidate and stop when a valid merge tool is found.
+	IFS=' '
+	for tool in $tools
+	do
+		is_available "$tool" && echo "$tool" && return 0
+	done
+
+	echo >&2 "No known ${TOOL_MODE} tool is available."
+	return 1
+}
+
+get_configured_merge_tool () {
+	keys=
+	if diff_mode
+	then
+		if gui_mode
+		then
+			keys="diff.guitool merge.guitool diff.tool merge.tool"
+		else
+			keys="diff.tool merge.tool"
+		fi
+	else
+		if gui_mode
+		then
+			keys="merge.guitool merge.tool"
+		else
+			keys="merge.tool"
+		fi
+	fi
+
+	merge_tool=$(
+		IFS=' '
+		for key in $keys
+		do
+			selected=$(git config $key)
+			if test -n "$selected"
+			then
+				echo "$selected"
+				return
+			fi
+		done)
+
+	if test -n "$merge_tool" && ! valid_tool "$merge_tool"
+	then
+		echo >&2 "git config option $TOOL_MODE.${gui_prefix}tool set to unknown tool: $merge_tool"
+		echo >&2 "Resetting to default..."
+		return 1
+	fi
+	echo "$merge_tool"
+}
+
+get_merge_tool_path () {
+	# A merge tool has been set, so verify that it's valid.
+	merge_tool="$1"
+	if ! valid_tool "$merge_tool"
+	then
+		echo >&2 "Unknown merge tool $merge_tool"
+		exit 1
+	fi
+	if diff_mode
+	then
+		merge_tool_path=$(git config difftool."$merge_tool".path ||
+				  git config mergetool."$merge_tool".path)
+	else
+		merge_tool_path=$(git config mergetool."$merge_tool".path)
+	fi
+	if test -z "$merge_tool_path"
+	then
+		merge_tool_path=$(translate_merge_tool_path "$merge_tool")
+	fi
+	if test -z "$(get_merge_tool_cmd "$merge_tool")" &&
+		! type "$merge_tool_path" >/dev/null 2>&1
+	then
+		echo >&2 "The $TOOL_MODE tool $merge_tool is not available as"\
+			 "'$merge_tool_path'"
+		exit 1
+	fi
+	echo "$merge_tool_path"
+}
+
+get_merge_tool () {
+	is_guessed=false
+	# Check if a merge tool has been configured
+	merge_tool=$(get_configured_merge_tool)
+	# Try to guess an appropriate merge tool if no tool has been set.
+	if test -z "$merge_tool"
+	then
+		merge_tool=$(guess_merge_tool) || exit
+		is_guessed=true
+	fi
+	echo "$merge_tool"
+	test "$is_guessed" = false
+}
+
+mergetool_find_win32_cmd () {
+	executable=$1
+	sub_directory=$2
+
+	# Use $executable if it exists in $PATH
+	if type -p "$executable" >/dev/null 2>&1
+	then
+		printf '%s' "$executable"
+		return
+	fi
+
+	# Look for executable in the typical locations
+	for directory in $(env | grep -Ei '^PROGRAM(FILES(\(X86\))?|W6432)=' |
+		cut -d '=' -f 2- | sort -u)
+	do
+		if test -n "$directory" && test -x "$directory/$sub_directory/$executable"
+		then
+			printf '%s' "$directory/$sub_directory/$executable"
+			return
+		fi
+	done
+
+	printf '%s' "$executable"
+}