[gentoo-portage-dev] [PATCH] eapply_user: combine sort for all dirs (bug 608880)

[Zac Medico]

Combine the patch basenames from all matched directories into a
list, and apply them in POSIX sorted order.  This allows patches in
more-specific directories to override patches of the same basename found
in less-specific directories. An empty patch (or /dev/null symlink)
negates a patch with the same basename found in a less-specific
directory.

This behavior is much more flexible and intuitive than the previous one,
while remaining backward-compatible to some extent.

NOTE: The implementation uses an associative array, which requires bash
version 4 or later.

X-Gentoo-bug: 608880
X-Gentoo-bug-url: https://bugs.gentoo.org/608880
---
 bin/phase-helpers.sh | 31 +++++++++++++++++++++++++------
 1 file changed, 25 insertions(+), 6 deletions(-)

diff --git a/bin/phase-helpers.sh b/bin/phase-helpers.sh
index 4b9b12b70..f8c2c34d4 100644
--- a/bin/phase-helpers.sh
+++ b/bin/phase-helpers.sh
@@ -1094,22 +1094,41 @@ if ___eapi_has_eapply_user; then
 
 		local basedir=${PORTAGE_CONFIGROOT%/}/etc/portage/patches
 
-		local d applied
+		local applied d f
+		local -A _eapply_user_patches
 		local prev_shopt=$(shopt -p nullglob)
 		shopt -s nullglob
 
-		# possibilities:
+		# Patches from all matched directories are combined into a
+		# sorted (POSIX order) list of the patch basenames. Patches
+		# in more-specific directories override patches of the same
+		# basename found in less-specific directories. An empty patch
+		# (or /dev/null symlink) negates a patch with the same
+		# basename found in a less-specific directory.
+		#
+		# order of specificity:
 		# 1. ${CATEGORY}/${P}-${PR} (note: -r0 desired to avoid applying
 		#    ${P} twice)
 		# 2. ${CATEGORY}/${P}
 		# 3. ${CATEGORY}/${PN}
 		# all of the above may be optionally followed by a slot
-		for d in "${basedir}"/${CATEGORY}/{${P}-${PR},${P},${PN}}{,:${SLOT%/*}}; do
-			if [[ -n $(echo "${d}"/*.diff) || -n $(echo "${d}"/*.patch) ]]; then
-				eapply "${d}"
+		for d in "${basedir}"/${CATEGORY}/{${P}-${PR},${P},${PN}}{:${SLOT%/*},}; do
+			for f in "${d}"/*; do
+				if [[ ( ${f} == *.diff || ${f} == *.patch ) &&
+					-z ${_eapply_user_patches[${f##*/}]} ]]; then
+					_eapply_user_patches[${f##*/}]=${f}
+				fi
+			done
+		done
+
+		while read -r -d '' f; do
+			f=${_eapply_user_patches[${f}]}
+			if [[ -s ${f} ]]; then
+				eapply "${f}"
 				applied=1
 			fi
-		done
+		done < <(printf -- "%s\0" "${!_eapply_user_patches[@]}" |
+			LC_ALL=C sort -z)
 
 		${prev_shopt}
 
-- 
2.13.0