Patch-by: Peter Alfredsen <loki_val@gentoo.org>

General installsources improvements

o Move the rsync run to the end so we only see errors about source files that have been moved
  once. Speeds up prepstrip as well.

o Optimize regexp used by grep so it catches anything after the last slash that looks like:
  <stdin>
  <built-in>
  <internal>

o Make rsync for installsources non-recursive. >=debugedit-4.4.6-r2 will now sometimes output
  directories. Earlier versions didn't, so the option wasn't used.
  This change requires that earlier versions of portage block >=debugedit-4.4.6-r2,
  otherwise when rsync is run, directories with all their contents will be installed
  in /usr/src/debug

o Preserve empty directories referenced in debug sections w.r.t.
  https://bugzilla.redhat.com/show_bug.cgi?id=444310

o Make installsources a bit more verbose, piping up when rsync is run.

--- portage-2.2_rc43/bin/ebuild-helpers/prepstrip.old	2009-08-21 16:52:01.000000000 +0200
+++ portage-2.2_rc43/bin/ebuild-helpers/prepstrip	2009-10-21 01:55:25.000000000 +0200
@@ -22,10 +22,11 @@
 
 # We'll leave out -R .note for now until we can check out the relevance
 # of the section when it has the ALLOC flag set on it ...
 export SAFE_STRIP_FLAGS="--strip-unneeded"
 export PORTAGE_STRIP_FLAGS=${PORTAGE_STRIP_FLAGS-${SAFE_STRIP_FLAGS} -R .comment}
+prepstrip_sources_dir=/usr/src/debug/${CATEGORY}/${PF}
 
 if hasq installsources ${FEATURES} && ! type -P debugedit >/dev/null ; then
 	ewarn "FEATURES=installsources is enabled but the debugedit binary could not"
 	ewarn "be found. This feature will not work unless debugedit is installed!"
 fi
@@ -46,21 +47,14 @@
 	type -P debugedit >/dev/null || return 0
 
 	local x=$1
 	local inode=$(inode_var_name "$x")
 	[[ -n ${!inode} ]] && return 0
-	local sources_dir=/usr/src/debug/${CATEGORY}/${PF}
-	debugedit -b "${WORKDIR}" -d "${sources_dir}" \
+	debugedit -b "${WORKDIR}" -d "${prepstrip_sources_dir}" \
 		-l "${T}"/debug.sources "${x}"
-	if [[ -s ${T}/debug.sources ]] ; then 
-		[[ -d ${D}${sources_dir} ]] || mkdir -p "${D}${sources_dir}"
-		grep -zv '/<built-in>$' "${T}"/debug.sources | \
-			(cd "${WORKDIR}"; LANG=C sort -z -u | \
-			rsync -rtL0 --files-from=- "${WORKDIR}/" "${D}${sources_dir}/" )
-	fi
 }
- 
+
 save_elf_debug() {
 	hasq splitdebug ${FEATURES} || return 0
 
 	local x=$1
 	local y="${D}usr/lib/debug/${x:${#D}}.debug"
@@ -176,5 +170,25 @@
 			[[ ${x} == *.ko ]] && save_elf_debug "${x}"
 			${STRIP} ${SAFE_STRIP_FLAGS} "${x}"
 		fi
 	fi
 done
+
+if [[ -s ${T}/debug.sources ]] && \
+        hasq installsources ${FEATURES} && \
+        ! hasq installsources ${RESTRICT} && \
+        type -P debugedit >/dev/null
+then
+	vecho "installsources: rsyncing source files"
+	[[ -d ${D}${prepstrip_sources_dir} ]] || mkdir -p "${D}${prepstrip_sources_dir}"
+	grep -zv '/<[^/>]*>$' "${T}"/debug.sources | \
+		(cd "${WORKDIR}"; LANG=C sort -z -u | \
+		rsync -tL0 --files-from=- "${WORKDIR}/" "${D}${prepstrip_sources_dir}/" )
+
+	# Preserve directory structure.
+	# Needed after running save_elf_sources.
+	# https://bugzilla.redhat.com/show_bug.cgi?id=444310
+	while read -r emptydir
+	do
+		touch "$emptydir"/.keepdir
+	done < <(find "${D}${prepstrip_sources_dir}/" -type d -empty)
+fi