# This file contains the common functions used in all quilt script
# It is meant to be sourced by bash scripts.

#  This script is free software; you can redistribute it and/or modify
#  it under the terms of the GNU General Public License version 2 as
#  published by the Free Software Foundation.
#
#  See the COPYING and AUTHORS files for more details.

export TEXTDOMAIN=quilt
if [ -n "$STAGING_DIR_HOST" ]; then
	export TEXTDOMAINDIR="$STAGING_DIR_HOST/share/locale"
else
	export TEXTDOMAINDIR=/home/user/librerouteros-C50/staging_dir/host/share/locale
fi

: ${LC_CTYPE:=$LANG}
: ${LC_MESSAGES:=$LANG}
ORIGINAL_LANG=$LANG
export LANG=POSIX

DB_VERSION=2

: ${QUILT_PC:=.pc}

# Support compatibility layer
if [ -d $QUILT_DIR/compat ]
then
	export PATH="$QUILT_DIR/compat:$PATH"
fi

unset CDPATH
shopt -s dotglob

if [ -e "$QUILTRC" ]
then
	source "$QUILTRC"
fi

# Add default arguments for this command
if [ -n "$QUILT_COMMAND" ]; then
	args="QUILT_$(echo $QUILT_COMMAND | tr a-z A-Z)_ARGS"
	eval set -- ${!args} \"\$@\"
	unset args
fi

. $QUILT_DIR/scripts/utilfns

# ========================================================

declare -a exit_handlers

add_exit_handler()
{
	exit_handlers[${#exit_handlers[@]}]=$1
}

remove_exit_handler()
{
	declare -a handlers
	local h
	for h in "${exit_handlers[@]}"
	do
		[ "$h" = "$1" ] && continue
		handlers[${#handlers[@]}]=$h
	done
	exit_handlers=( "${handlers[@]}" )
}

run_exit_handlers()
{
	local h
	for h in "${exit_handlers[@]}"
	do
		eval $h
	done
}

trap run_exit_handlers EXIT

# ========================================================

# Join multiple stings using the given separator.
array_join()
{
	local sep=$1 str=$2
	shift 2

	printf %s "$str"

	for str in "$@"
	do
		printf %s%s "$sep" "$str"
	done
}

# Quote a string for use in a basic regular expression.
quote_bre()
{
	echo "$1" | sed -e 's:\([][^$/.*\\]\):\\\1:g'
}

# Quote a string for use in an extended regular expression.
quote_re()
{
	echo "$1" | sed -e 's:\([][?{(|)}^$/.+*\\]\):\\\1:g'
}

# Quote a string for use in a globing pattern.
quote_glob()
{
	echo "$1" | sed -e 's:\([][*?\\]\):\\\1:g'
}

patch_file_name()
{
	echo "$QUILT_PATCHES/$1"
}

# The -pN option and possibly others that should be passed to patch.
patch_args()
{
	local patch=$1

	if [ -e $SERIES ]
	then
		awk '
			{sub(/(^|[ \t]+)#.*/, "") }
		$1 == "'"$patch"'" \
			{ p_printed=0
			  for (i=2; i<=NF; i++) {
				print $i
				if ($i ~ /^-p/)
					p_printed=1
			  }
			  if (!p_printed)
				print "-p1" ;
			  exit
			}
		' $SERIES
	fi
}

patch_strip_level()
{
	local patch=$1 i
	for i in $(patch_args $patch)
	do
		case $i in
		-p*)
			echo ${i:2}
			return ;;
		esac
	done
	echo "1"
}

# Also remove -R if present.
change_db_strip_level()
{
	local level=$1 patch=$2

	if [ x$level != x-p1 ]
	then
		level="$level"
	else
		level=""
	fi

	if [ -e $SERIES ]
	then
		local tmpfile=$(gen_tempfile)
		awk '
		function remove_arg(nr, j) {
			for (j=nr; j<NF; j++)
				$j=$(j+1)
			NF--
		}
		function insert_arg(nr, value, j) {
			for (j=NF; j>=nr; j--)
				$(j+1)=$j
			$nr=value
		}

		/^'"$(quote_re $patch)"'([ \t]|$)/ \
			{ p_printed=0
			  for (i=2; i<=NF && $i !~ /^#/; i++) {
				if ($i ~ /^-p/) {
					if ("'"$level"'" == "")
						remove_arg(i--)
					else
						$i="'"$level"'"
					p_printed=1
					continue
				}
				if ($i == "-R") {
					remove_arg(i--)
					continue
				}
			  }
			  if (!p_printed && "'"$level"'" != "")
				insert_arg(2, "'"$level"'")
			}
			{ print }
		' $SERIES > $tmpfile
		if ! cmp $SERIES $tmpfile >/dev/null 2>/dev/null
		then
			cat $tmpfile > $SERIES
		fi
		rm -f $tmpfile
	else
		return 1
	fi
}

patch_in_series()
{
	local patch=$1

	if [ -e $SERIES ]
	then
		grep -q "^$(quote_bre $patch)\([ \t]\|$\)" $SERIES
	else
		return 1
	fi
}

# Insert new patch after topmost patch
insert_in_series()
{
	local patch=$1 patch_args=$2
	local before tmpfile

	if [ -e "$SERIES" -a ! -f "$SERIES" ]; then
		printf $"%s is not a regular file\n" "$SERIES" >&2
		return 1
	fi

	before=${3-$(patch_after "$(top_patch)")}

	if [ -n "$patch_args" ]
	then
		patch_args=" $patch_args"
	fi

	tmpfile=$(gen_tempfile) || return 1
	mkdir -p $(dirname $SERIES)
	if [ -n "$before" ]
	then
		awk '
		/^'"$(quote_re $before)"'([ \t]|$)/ \
				{ print "'"$patch$patch_args"'" }
				{ print }
		' "$SERIES" > $tmpfile
		status=$?
		if [ $status -ne 0 ]
		then
			rm -f $tmpfile
			return 1
		fi
	else
		if [ -e "$SERIES" ]
		then
			cat "$SERIES" > $tmpfile
		fi
		echo "$patch$patch_args" >> $tmpfile
	fi
	cat $tmpfile > "$SERIES"
	rm -f $tmpfile
}

remove_from_series()
{
	local patch=$1

	tmpfile=$(gen_tempfile) || return 1
	awk '
	! /^'"$(quote_re $patch)"'([ \t]|$)/ \
				{ print }
	' $SERIES > $tmpfile
	if [ $? -ne 0 ]
	then
		rm -f $tmpfile
		return 1
	fi
	cat $tmpfile > $SERIES
	rm -f $tmpfile
}

rename_in_series()
{
	local from=$1 to=$2

	tmpfile=$(gen_tempfile) || return 1
	awk '
	/^'"$(quote_re $from)"'([ \t]|$)/ \
		{ sub(/'"$(quote_re $from)"'/, "'"${to//\"/\\\"}"'")
		  good=1 }
		{ print }
	END	{ exit(! good) }
	' $SERIES > $tmpfile
	if [ $? -ne 0 ]
	then
		rm -f $tmpfile
		return 1
	fi
	cat $tmpfile > $SERIES
	rm -f $tmpfile
}

rename_in_db()
{
	local from=$1 to=$2
	local tmpfile
	tmpfile=$(gen_tempfile) || return 1
	awk '
	/^'"$(quote_re $from)"'$/ \
		{ sub(/'"$(quote_re $from)"'/, "'"${to//\"/\\\"}"'")
		  good=1 }
		{ print }
	END	{ exit(! good) }
	' $DB > $tmpfile
	if [ $? -eq 0 ]
	then
		cat $tmpfile > $DB
		rm -f $tmpfile
	else
		rm -f $tmpfile
		return 1
	fi
}

backup_file_name()
{
	local patch=$1
	while [ $# -gt 1 ]
	do
		echo "$QUILT_PC/$patch/$2"
		shift
	done
}

cat_series()
{
	if [ -e $SERIES ]
	then
		sed -e '/^#/d' -e 's/^[ '$'\t'']*//' \
		    -e 's/[ '$'\t''].*//' -e '/^$/d' $SERIES
	else
		return 1
	fi
}

top_patch()
{
	local patch=$(tail -n 1 $DB 2>/dev/null)
	[ -n "$patch" ] && echo "$patch"
}

is_numeric()
{
	[[ "$1" =~ ^[0-9]+$ ]]
}

is_applied()
{
	local patch=$1
	[ -e $DB ] || return 1
	grep -q "^$(quote_bre $patch)\$" $DB
}

applied_patches()
{
	[ -e $DB ] || return 1
	cat $DB
}

applied_before()
{
	local patch=$1

	if [ -n "$patch" ]
	then
		awk '
		$0 == "'"$patch"'"	{ exit }
					{ print }
		' $DB
	fi
}

patches_before()
{
	local patch=$1

	if [ -n "$patch" ]
	then
		cat_series \
		| awk '
		$0 == "'"$patch"'"	{ exit }
					{ print }
		'
	fi
}

patches_after()
{
	local patch=$1
	if [ -n "$patch" ]
	then
		cat_series \
		| awk '
		seen == 1		{ print }
		$0 == "'"$patch"'"	{ seen=1 }
		'
	else
		cat_series
	fi
}

patch_after()
{
	local patch="$1"
	patch=$(patches_after "$patch" | head -n 1)
	[ -n "$patch" ] && echo "$patch"
}

# List all patches that have been applied on top of patch $1
patches_on_top_of()
{
	local patch=$1
	[ -e $DB ] || return
	awk '
	$0 == "'"$patch"'"	{ seen=1 ; next }
	seen == 1		{ print }
	' $DB
}

# Print the name of the patch that modified the file $2 next after
# patch $1, or print nothing if patch $1 is on top.
next_patch_for_file()
{
	local patch=$1 file=$2
	local patches_on_top=$(patches_on_top_of $patch)

	if [ -n "$patches_on_top" ]
	then
		for patch in $patches_on_top
		do
			if file_in_patch "$file" $patch
			then
				echo $patch
				break
			fi
		done
	fi
}

add_to_db()
{
	echo $1 >> $DB
}

remove_from_db()
{
	local patch=$1
	local tmpfile
	if tmpfile=$(gen_tempfile)
	then
		grep -v "^$(quote_bre $patch)\$" $DB > $tmpfile
		cat $tmpfile > $DB
		rm -f $tmpfile
		[ -s $DB ] || rm -f $DB
	fi
}

find_first_patch()
{
	local patch=$(cat_series | head -n 1)
	if [ -z "$patch" ]
	then
		if [ -e "$SERIES" ]
		then
			printf $"No patches in series\n" >&2
		else
			printf $"No series file found\n" >&2
		fi
		return 1
	fi

	echo "$patch"
}

find_last_patch()
{
	local patch=$(cat_series | tail -n 1)
	if [ -z "$patch" ]
	then
		if [ -e "$SERIES" ]
		then
			printf $"No patches in series\n" >&2
		else
			printf $"No series file found\n" >&2
		fi
		return 1
	fi

	echo "$patch"
}

find_top_patch()
{
	if ! top_patch
	then
		if find_first_patch > /dev/null
		then
			printf $"No patches applied\n" >&2
		fi
		return 1
	fi
}

find_patch()
{
	local name="$1"
	if [ -e "$SERIES" ]
	then
		if ! [ -f "$SERIES" ]
		then
			printf $"%s is not a regular file\n" "$SERIES" >&2
			return 1
		fi

		local patch=${1#$SUBDIR_DOWN$QUILT_PATCHES/}
		local bre=$(quote_bre "$patch")
		set -- $(sed -e "/^$bre\(\|\.patch\|\.diff\?\)\(\|\.gz\|\.bz2\|\.xz\|\.lzma\)\([ "$'\t'"]\|$\)/!d" \
			       -e 's/[ '$'\t''].*//' $SERIES)
		if [ $# -eq 1 ]
		then
			echo $1
			return 0
		else
			# We may have an exact match, which overrides
			# extension expansion
			while [ $# -gt 0 ]
			do
				if [ $1 = "$patch" ]
				then
					echo $1
					return 0
				fi
				shift
			done
		fi
	fi
	# Finding the first patch will error when the series is empty
	if [ -n "$(find_first_patch)" ]
	then
		printf $"Patch %s is not in series\n" "$name" >&2
	fi
	return 1
}

find_patch_in_series()
{
	local name="$1"

	if [ -n "$name" ]
	then
		find_patch "$name"
	else
		find_top_patch
	fi
}

find_applied_patch()
{
	local name="$1"

	if [ -n "$name" ]
	then
		local patch

		patch=$(find_patch "$name") || return 1
		if ! is_applied "$patch"
		then
			printf $"Patch %s is not applied\n" \
			       "$(print_patch $patch)" >&2
			return 1
		fi
		echo "$patch"
	else
		find_top_patch
	fi
}

find_unapplied_patch()
{
	local name="$1"

	if [ -n "$name" ]
	then
		local patch

		patch=$(find_patch "$name") || return 1
		if is_applied "$patch"
		then
			printf $"Patch %s is currently applied\n" \
				"$(print_patch $patch)" >&2
			return 2
		fi
		echo "$patch"
	else
		local start

		if start=$(top_patch)
		then
			patch_after "$start"
		else
			find_first_patch || return 2
		fi
		if [ $? -ne 0 ]
		then
			printf $"File series fully applied, ends at patch %s\n" \
				"$(print_patch $start)" >&2
			return 2
		fi
	fi
}

file_in_patch()
{
	local file=$1 patch=$2
	[ -f "$QUILT_PC/$patch/$file" ]
}

files_in_patch()
{
	local patch="$1"
	local path="$QUILT_PC/$patch"

	if [ -d "$path" ]
	then
		find "$path" -type f \
			       -a ! -path "$(quote_glob "$path")/.timestamp" |
		sed -e "s/$(quote_bre "$path")\///"
	fi
}

# Note that we can only guess which files a patch touches because of the
# complicated heuristics that patch uses (see "Multiple Patches in a File"
# in the diff info pages).
filenames_in_patch()
{
	local patch=$1
	local patch_file=$(patch_file_name $patch)
	if [ -e "$patch_file" ]
	then
		local strip=$(patch_strip_level $patch)
		[ "$strip" = ab ] && strip=1
		awk '
		$1 == "+++" || $1 == "---" && $3 != "----" || \
		$1 == "***" && $3 != "****" \
			{ sub(/\t.*/, "")
			  if (sub(/^... /, "") == 0 || $0 == "" || $0 == "/dev/null")
				next
			  for (n=0 ; n<'$strip'; n++)
			      sub(/^[^\/]+\//, "")
			  if (!printed[$0]++)
			      print $0 }' $patch_file
	fi
}

files_in_patch_ordered()
{
	local patch=$1

	(   files_in_patch $patch | sort
	    echo "-"
	    filenames_in_patch $patch
	) | awk '
	$1 == "-" { out=1 ; next }
	!out	{ files[$0]=1
		  new_files[++n]=$0 }
	out	{ if ($0 in files) {
		    print $0
		    printed[$0]=1
		  }
		}
	END	{
		  for (i=1; i<=n; i++)
		    if (!(new_files[i] in printed))
		      print new_files[i]
		}
	'
}

diff_file()
{
	local file=$1 old_file=$2 new_file=$3
	local index old_hdr old_date new_hdr new_date line

	: ${opt_strip_level:=1}
	if [ $opt_strip_level = ab ]
	then
		old_hdr=a/$file
		new_hdr=b/$file
	elif [ $opt_strip_level -eq 0 ]
	then
		old_hdr=$file.orig
		new_hdr=$file
	else
		local dir=$(basename $PWD)
		old_hdr=$dir.orig/$file
		new_hdr=$dir/$file
	fi
	index=$new_hdr

	if [ -s "$old_file" ]
	then
		[ -n "$QUILT_NO_DIFF_TIMESTAMPS" ] \
		|| old_date=$'\t'$(date +'%Y-%m-%d %H:%M:%S.%N %z' \
					-r "$old_file")
	else
		old_file=/dev/null
		old_hdr=/dev/null
		[ -n "$QUILT_NO_DIFF_TIMESTAMPS" ] \
		|| old_date=$'\t'"1970-01-01 00:00:00.000000000 +0000"
	fi
	if [ -e "$new_file" ]
	then
		[ -n "$QUILT_NO_DIFF_TIMESTAMPS" ] \
		|| new_date=$'\t'$(date +'%Y-%m-%d %H:%M:%S.%N %z' \
					-r "$new_file")
	else
		[ $opt_strip_level = 0 ] \
		&& old_hdr=$new_hdr
		new_file=/dev/null
		new_hdr=/dev/null
		[ -n "$QUILT_NO_DIFF_TIMESTAMPS" ] \
		|| new_date=$'\t'"1970-01-01 00:00:00.000000000 +0000"
	fi

	diff $QUILT_DIFF_OPTS \
	     --label "$old_hdr$old_date" --label "$new_hdr$new_date" \
	     "$old_file" "$new_file" \
	| if read line
	then
		local status=0

		if [[ "$line" =~ ^Binary\ files\ .*\ differ$ ]]
		then
			status=1
		elif [ -z "$QUILT_NO_DIFF_INDEX" ]
		then
			echo "Index: $index"
			echo "==================================================================="
		fi

		echo "$line"
		cat

		return $status
	fi

	# Test the return value of diff, and propagate the error retcode if any
	if [ ${PIPESTATUS[0]} == 2 -o ${PIPESTATUS[1]} == 1 ]
	then
		printf $"Diff failed on file '%s', aborting\n" "$new_file" >&2
		return 1
	fi
}

cat_file()
{
	local filename

	for filename in "$@"
	do
		if [ -e "$filename" ]
		then
			case "$filename" in
			*.gz|*.tgz)
				gzip -cd "$filename" ;;
			*.bz2)
				bzip2 -cd "$filename" ;;
			*.xz)
				xz -cd "$filename" ;;
			*.lzma)
				lzma -cd "$filename" ;;
			*)
				cat "$filename" ;;
			esac
		fi
	done
}

cat_to_new_file()
{
	local filename=$1 backup=$2

	# If the file exists, back it up if requested. Return immediately upon
	# failure.
	if [ -e "$filename" -a -n "$backup" ]
	then
		if [ -L "$filename" ]
		then
			cp -p "$filename" "$filename~"
		else
			mv "$filename" "$filename~"
		fi || return
	fi

	# If the destination file is a symbolic link, preserve it unless its
	# target is read-only. In other cases, delete the patch file first in
	# case it has hard links.
	if [ -e "$filename" -a ! \( -L "$filename" -a -w "$filename" \) ]
	then
		rm -f "$filename"
	fi

	case "$filename" in
	*.gz)
		gzip -c ;;
	*.bz2)
		bzip2 -c ;;
	*.xz)
		xz -c ;;
	*.lzma)
		lzma -c ;;
	*)
		cat ;;
	esac \
	> "$filename"
}

patch_header()
{
	awk '
	/^(---|\*\*\*|Index:)[ \t][^ \t]|^diff -/ \
		{ exit }
		{ print }
	'
}

patch_body()
{
	awk '
	!body && /^(---|\*\*\*|Index:)[ \t][^ \t]|^diff -/ \
		{ body=1 }
	body	{ print }
	'
}

strip_diffstat()
{
	awk '
	/#? .* \| / \
		{ eat = eat $0 "\n"
		  next }
	/^#? .* files? changed(, .* insertions?\(\+\))?(, .* deletions?\(-\))?/ \
		{ eat = ""
		  next }
		{ print eat $0
		  eat = "" }
	'
}

in_array()
{
	local a=$1
	while [ $# -gt 1 ]
	do
		shift
		[ "$a" = "$1" ] && return 0
	done
	return 1
}

first_modified_by()
{
	local file=$1 patch
	local -a patches
	if [ $# -eq 0 ]
	then
		patches=( $(applied_patches) )
	else
		shift
		patches=( "$@" )
	fi
	for patch in ${patches[@]}
	do
		if [ -f "$QUILT_PC/$patch/$file" ]
		then
			echo $patch
			return 0
		fi
	done
	return 1
}

apply_patch_temporarily()
{
	local workdir=$1 patch=$2 patch_file patch_args

	patch_file=$(patch_file_name "$patch")
	patch_args=$(patch_args "$patch")

	shift 2

	local prefix=$QUILT_PC/$patch/
	[ ${prefix:0:1} == / ] || prefix=$PWD/$prefix
	if ! ( cd $workdir && \
	       $QUILT_DIR/scripts/backup-files -B $prefix -r -k -s "${@:--}" )
	then
		printf $"Failed to copy files to temporary directory\n" >&2
		return 1
	fi

	if [ -s $patch_file ]
	then
		if ! cat_file $patch_file \
		     | patch -d $workdir $QUILT_PATCH_OPTS $patch_args \
			     --no-backup-if-mismatch -f \
			     >/dev/null 2>/dev/null
		then
			# Generating a relative diff for a subset of files in
			# the patch will fail. Also, if a patch was force
			# applied, we know that it won't apply cleanly. In
			# all other cases, print a warning.

			if [ ! -e $QUILT_PC/$patch~refresh -a $# -eq 0 ]
			then
				printf $"Failed to patch temporary files\n" >&2
				return 1
			fi
		fi
	fi
}

next_filename()
{
	local patch=$1 base num
	base=$(echo "$patch" \
	       | sed -r -e 's:(\.gz|\.bz2|\.xz|\.lzma)$::' -e 's:(\.diff?|\.patch)$::')
	num=$(echo "$base" | sed -nre 's:.*-([0-9]+)$:\1:'p)
	[ -n "$num" ] || num=1
	echo "${base%-$num}-$((num+1))${patch#$base}"
}

create_db()
{
	if ! [ -e $QUILT_PC ]
	then
		mkdir -p $QUILT_PC
		echo $DB_VERSION > $QUILT_PC/.version
	fi
	if ! [ -e $QUILT_PC/.quilt_patches ]
	then
		echo "$QUILT_PATCHES" > $QUILT_PC/.quilt_patches
	fi
	if ! [ -e $QUILT_PC/.quilt_series ]
	then
		echo "$QUILT_SERIES" > $QUILT_PC/.quilt_series
	fi
}

version_check()
{
	[ -e $QUILT_PC ] || return 0

	if [ -e $QUILT_PC/.version ]
	then
		version="$(< $QUILT_PC/.version)"
		if [ "$version" -gt $DB_VERSION ]
		then
			printf $"The quilt meta-data in this tree has version %s, but this version of quilt can only handle meta-data formats up to and including version %s. Please pop all the patches using the version of quilt used to push them before downgrading.\n" "$version" "$DB_VERSION" >&2
			exit 1
		elif [ "$version" = $DB_VERSION ]
		then
			return 0
		fi
	fi
	return 1
}

consistency_check()
{
	local top applied patches

	top=$(top_patch)
	applied=$(applied_before "$top")
	patches=$(patches_before "$top")

	if [ "$applied" != "$patches" ]
	then
		return 1
	else
		# Skip check until series file is modified again
		touch "$DB"
		return 0
	fi
}

print_patch()
{
	echo "${QUILT_PATCHES_PREFIX:+$SUBDIR_DOWN$QUILT_PATCHES/}$1"
}

# Generate a format suitable to print patch names with printf
patch_format()
{
	local prefix=${QUILT_PATCHES_PREFIX:+$SUBDIR_DOWN$QUILT_PATCHES/}

	echo -n "${prefix/\%/%%}%s"
}

setup_colors()
{
	local C=diff_hdr=32:diff_add=36:diff_mod=35:diff_rem=35:diff_hunk=33:diff_ctx=35:diff_cctx=33:patch_offs=33:patch_fuzz=35:patch_fail=31:series_app=32:series_top=33:series_una=00:clear=00
	[ -n "$QUILT_COLORS" ] && C="$C:$QUILT_COLORS"

	C=${C//=/=\'$'\e'[}
	C=color_${C//:/m\'; color_}m\'
	eval $C
}

quilt_command()
{
	local command=$1
	shift

	# Refreshing here must produce the same output as "quilt refresh" on
	# the command line
	export QUILT_NO_DIFF_INDEX
	export QUILT_NO_DIFF_TIMESTAMPS

	QUILT_COMMAND="" bash $BASH_OPTS -c "${SUBDIR:+cd $SUBDIR;} . $QUILT_DIR/$command" "quilt $command" "$@"
}

check_external_tool()
{
	local tool=$1 package=$2 options=$3
	local command=$QUILT_COMMAND

	[ -n "$options" ] && command="$command $options"

	if ! type "$tool" &> /dev/null
	then
		printf $"You have to install '%s' (from package %s) to use 'quilt %s'\n" \
		       "$tool" "$package" "$command" >&2
		exit 1
	fi
}

declare pager_fifo pager_fifo_dir pager_pid

wait_for_pager()
{
	exec >&-
	wait $pager_pid
	rm $pager_fifo 2>/dev/null
	rmdir $pager_fifo_dir 2>/dev/null
}

wait_for_pager_signal()
{
	remove_exit_handler wait_for_pager
	wait_for_pager
	trap - INT HUP TERM QUIT
}

# Spawn pager process and redirect the rest of our output to it
setup_pager()
{
	test -t 1 || return 0

	# QUILT_PAGER = QUILT_PAGER | GIT_PAGER | PAGER | less -R
	# NOTE: QUILT_PAGER='' is significant
	QUILT_PAGER=${QUILT_PAGER-${GIT_PAGER-${PAGER-less -R}}}

	[ -z "$QUILT_PAGER" -o "$QUILT_PAGER" = "cat" ]  && return 0

	export LESS="${LESS:-FRSX}"

	# NOTE: with "exec > >($pager)" there is no way to get the pid of the
	# pager so we can't wait for it to complete.  Otherwise we wouldn't
	# need temporary files here.  Alternatively, in recent versions of
	# bash, a coprocess could be used instead.

	pager_fifo_dir="$(gen_tempfile -d)"
	pager_fifo="$pager_fifo_dir/0"
	mkfifo -m 600 "$pager_fifo"
	$QUILT_PAGER < "$pager_fifo" &
	pager_pid=$!
	exec > "$pager_fifo"

	trap wait_for_pager_signal INT HUP TERM QUIT
	add_exit_handler wait_for_pager
}

#
# If the working directory does not contain a $QUILT_PATCHES directory,
# quilt searches for its base directory up the directory tree. If no
# $QUILT_PATCHES directory exists, the quilt operations that create
# patches will create $QUILT_PATCHES in the current working directory.
#
# When quilt is invoked from a directory below the base directory, it
# changes into the base directory, and sets $SUBDIR to the relative
# path from the base directory to the directory in which it was
# invoked. (e.g., if quilt is invoked in /usr/src/linux/drivers/net
# and the base direcory is /usr/src/linux, $SUBDIR is set to
# drivers/net/.

unset SUBDIR SUBDIR_DOWN
if ! [ -d "$QUILT_PC" -o -d "${QUILT_PATCHES:-patches}" ]
then
    basedir=$PWD
    while [ -n "$basedir" ]
    do
	basedir=${basedir%/*}
	down=$down../
	if [ -d "$basedir/$QUILT_PC" -o -d "$basedir/${QUILT_PATCHES:-patches}" ]
	then
	    SUBDIR="${PWD#$basedir/}/"
	    SUBDIR_DOWN=$down
	    if ! cd $basedir/
	    then
		printf $"Cannot change into parent directory %s/\n" "$basedir" >&2
		exit 1
	    fi
	    break
	fi
    done
    unset basedir down
fi

if [ -r $QUILT_PC/.quilt_patches ]
then
	QUILT_PATCHES=$(< $QUILT_PC/.quilt_patches)
else
	: ${QUILT_PATCHES:=patches}
fi
if [ -r $QUILT_PC/.quilt_series ]
then
	QUILT_SERIES=$(< $QUILT_PC/.quilt_series)
else
	: ${QUILT_SERIES:=series}
fi

if [ "${QUILT_SERIES:0:1}" = / ]
then
	SERIES=$QUILT_SERIES
elif [ -f $QUILT_PC/$QUILT_SERIES ]
then
	SERIES=$QUILT_PC/$QUILT_SERIES
elif [ -f $QUILT_SERIES ]
then
	SERIES=$QUILT_SERIES
else
	SERIES=$QUILT_PATCHES/$QUILT_SERIES
fi

DB="$QUILT_PC/applied-patches"

if [ -z "$skip_version_check" ]
then
	if ! version_check
	then
		printf $"The working tree was created by an older version of quilt. Please run 'quilt upgrade'.\n" >&2
		exit 1
	fi

	# Check if series file was modified manually, and if this is the case,
	# make sure it is still consistent with the applied patches
	if [ -s "$DB" -a ! "$DB" -nt "$SERIES" ] && [ "$QUILT_COMMAND" != pop ] && ! consistency_check
	then
		printf $"The series file no longer matches the applied patches. Please run 'quilt pop -a'.\n" >&2
		exit 1
	fi
fi