[gentoo-dev] [PATCH 11/14] cdrom.eclass: Make CD_ROOT less of a special case, fixes #195868

[James Le Cuirot]

CD_ROOT was intended to be a power user feature so the eclass didn't
try very hard to check the validity of the given location. This
difference in behaviour ultimately made the eclass larger and more
confusing.

It now uses the same matching loop as the regular case, making it
simpler and more consistent. The only differences are that it doesn't
show information or prompts about inserting discs and it dies
immediately if a match cannot be found.
---
 eclass/cdrom.eclass | 126 +++++++++++++++++++---------------------------------
 1 file changed, 46 insertions(+), 80 deletions(-)

diff --git a/eclass/cdrom.eclass b/eclass/cdrom.eclass
index 95bf48829e14..f4ea2ff36400 100644
--- a/eclass/cdrom.eclass
+++ b/eclass/cdrom.eclass
@@ -48,44 +48,16 @@ fi
 #
 # For those multi cd ebuilds, see the cdrom_load_next_cd() function.
 cdrom_get_cds() {
-	# first we figure out how many cds we're dealing with by
-	# the # of files they gave us
-	local cdcnt=0
-	local f=
-	export CDROM_CURRENT_CD=1 CDROM_CHECKS=( "${@}" )
+	unset CDROM_SET
+	export CDROM_CURRENT_CD=0 CDROM_CHECKS=( "${@}" )
 
-	# now we see if the user gave use CD_ROOT ...
-	# if they did, let's just believe them that it's correct
+	# If the user has set CD_ROOT or CD_ROOT_1, don't bother informing
+	# them about which discs are needed as they presumably already know.
 	if [[ -n ${CD_ROOT}${CD_ROOT_1} ]] ; then
-		local var=
-		cdcnt=0
-		while [[ ${cdcnt} -lt ${#} ]] ; do
-			((++cdcnt))
-			var="CD_ROOT_${cdcnt}"
-			[[ -z ${!var} ]] && var="CD_ROOT"
-			if [[ -z ${!var} ]] ; then
-				eerror "You must either use just the CD_ROOT"
-				eerror "or specify ALL the CD_ROOT_X variables."
-				eerror "In this case, you will need" \
-					"${#} CD_ROOT_X variables."
-				die "could not locate CD_ROOT_${cdcnt}"
-			fi
-		done
-		export CDROM_ROOT=${CD_ROOT_1:-${CD_ROOT}}
-		einfo "Found CD #${CDROM_CURRENT_CD} root at ${CDROM_ROOT}"
-		export CDROM_SET=-1
-		IFS=:
-		for f in ${CDROM_CHECKS[0]} ; do
-			unset IFS
-			((++CDROM_SET))
-			export CDROM_MATCH=$(_cdrom_glob_match "${CDROM_ROOT}" "${f}")
-			[[ -n ${CDROM_MATCH} ]] && return
-		done
-	fi
+		:
 
-	# User didn't help us out so lets make sure they know they can
-	# simplify the whole process ...
-	if [[ ${#} -eq 1 ]] ; then
+	# Single disc info.
+	elif [[ ${#} -eq 1 ]] ; then
 		einfo "This ebuild will need the ${CDROM_NAME:-cdrom for ${PN}}"
 		echo
 		einfo "If you do not have the CD, but have the data files"
@@ -96,6 +68,8 @@ cdrom_get_cds() {
 		einfo "For example:"
 		einfo "export CD_ROOT=/mnt/cdrom"
 		echo
+
+	# Multi disc info.
 	else
 		_cdrom_set_names
 		einfo "This package may need access to ${#} cds."
@@ -120,8 +94,7 @@ cdrom_get_cds() {
 		echo
 	fi
 
-	export CDROM_SET=""
-	export CDROM_CURRENT_CD=0
+	# Scan for the first disc.
 	cdrom_load_next_cd
 }
 
@@ -135,57 +108,48 @@ cdrom_get_cds() {
 # in the CD list, so make sure you only call this function when you're
 # done using the current CD.
 cdrom_load_next_cd() {
-	local var
-	((++CDROM_CURRENT_CD))
-
-	_cdrom_set_names
+	local showedmsg=0 showjolietmsg=0
 
 	unset CDROM_ROOT
-	var=CD_ROOT_${CDROM_CURRENT_CD}
-	[[ -z ${!var} ]] && var="CD_ROOT"
-	if [[ -z ${!var} ]] ; then
-		_cdrom_locate_file_on_cd "${CDROM_CHECKS[${CDROM_CURRENT_CD}]}"
-	else
-		export CDROM_ROOT=${!var}
-	fi
-
-	einfo "Found CD #${CDROM_CURRENT_CD} root at ${CDROM_ROOT}"
-}
-
-# this is used internally by the cdrom_get_cds() and cdrom_load_next_cd()
-# functions.  this should *never* be called from an ebuild.
-# all it does is try to locate a give file on a cd ... if the cd isn't
-# found, then a message asking for the user to insert the cdrom will be
-# displayed and we'll hang out here until:
-# (1) the file is found on a mounted cdrom
-# (2) the user hits CTRL+C
-_cdrom_locate_file_on_cd() {
-	local mline=""
-	local showedmsg=0 showjolietmsg=0
+	((++CDROM_CURRENT_CD))
 
-	while [[ -z ${CDROM_ROOT} ]] ; do
-		local i=0 cdset
-		IFS=: read -a cdset <<< "${*}"
+	_cdrom_set_names
 
-		if [[ -n ${CDROM_SET} ]] ; then
-			cdset=( "${cdset[${CDROM_SET}]}" )
-		fi
+	while true ; do
+		local i cdset
+		: CD_ROOT_${CDROM_CURRENT_CD}
+		export CDROM_ROOT=${CD_ROOT:-${!_}}
+		IFS=: read -a cdset <<< "${CDROM_CHECKS[$((${CDROM_CURRENT_CD} - 1))]}"
+
+		for i in $(seq ${CDROM_SET:-0} ${CDROM_SET:-$((${#cdset[@]} - 1))}); do
+			local f=${cdset[${i}]} point= node= fs= opts=
+
+			if [[ -z ${CDROM_ROOT} ]] ; then
+				while read point node fs opts ; do
+					has "${fs}" cd9660 iso9660 udf || continue
+					point=${point//\040/ }
+					export CDROM_MATCH=$(_cdrom_glob_match "${point}" "${f}")
+					[[ -z ${CDROM_MATCH} ]] && continue
+					export CDROM_ROOT=${point}
+				done <<< "$(get_mounts)"
+			else
+				export CDROM_MATCH=$(_cdrom_glob_match "${CDROM_ROOT}" "${f}")
+			fi
 
-		while [[ -n ${cdset[${i}]} ]] ; do
-			local point= node= fs= foo=
-			while read point node fs foo ; do
-				[[ " cd9660 iso9660 udf " != *" ${fs} "* ]] && continue
-				point=${point//\040/ }
-				export CDROM_MATCH=$(_cdrom_glob_match "${point}" "${cdset[${i}]}")
-				[[ -z ${CDROM_MATCH} ]] && continue
-				export CDROM_ROOT=${point}
+			if [[ -n ${CDROM_MATCH} ]] ; then
+				export CDROM_ABSMATCH=${CDROM_ROOT}/${CDROM_MATCH}
 				export CDROM_SET=${i}
-				return
-			done <<< "$(get_mounts)"
-
-			((++i))
+				break 2
+			fi
 		done
 
+		# If we get here then we were unable to locate a match. If
+		# CDROM_ROOT is non-empty then this implies that a CD_ROOT
+		# variable was given and we should therefore abort immediately.
+		if [[ -n ${CDROM_ROOT} ]] ; then
+			die "unable to locate CD #${CDROM_CURRENT_CD} root at ${CDROM_ROOT}"
+		fi
+
 		echo
 		if [[ ${showedmsg} -eq 0 ]] ; then
 			if [[ ${#CDROM_CHECKS[@]} -eq 1 ]] ; then
@@ -218,6 +182,8 @@ _cdrom_locate_file_on_cd() {
 		fi
 		read || die "something is screwed with your system"
 	done
+
+	einfo "Found CD #${CDROM_CURRENT_CD} root at ${CDROM_ROOT}"
 }
 
 # @FUNCTION: _cdrom_glob_match
-- 
2.11.0