eutils.eclass: Show death notice only when user patches were really a…

…pplied

As part of the user requested feature from [Gentoo-Bug #543878]
eutils.eclass shows a warning regarding user applied patches in case of an
error [Link 1].

However this warning will always be shown even if no user patch were
applied at all (example: empty /etc/portage/<cat>/<pkg> directory).

This commit adds a new global variable "EPATCH_N_APPLIED_PATCHES" which
tracks the number of applied user patches. This allows us to only show the
notice when user patches were really applied.

Link: https://sources.gentoo.org/cgi-bin/viewvc.cgi/gentoo-x86/eclass/eutils.eclass?r1=1.443&r2=1.444

Gentoo-Bug: https://bugs.gentoo.org/543878

eclass/eutils.eclass

@@ -595,6 +595,8 @@ epatch() {
 			: $(( count++ ))
 		done
 
+		(( EPATCH_N_APPLIED_PATCHES++ ))
+
 		# if we had to decompress the patch, delete the temp one
 		if [[ -n ${PIPE_CMD} ]] ; then
 			rm -f "${PATCH_TARGET}"
@@ -1736,13 +1738,17 @@ epatch_user() {
 		[[ -r ${EPATCH_SOURCE} ]] || EPATCH_SOURCE=${EPATCH_USER_SOURCE}/${CHOST}/${check}
 		[[ -r ${EPATCH_SOURCE} ]] || EPATCH_SOURCE=${EPATCH_USER_SOURCE}/${check}
 		if [[ -d ${EPATCH_SOURCE} ]] ; then
+			local old_n_applied_patches=${EPATCH_N_APPLIED_PATCHES:-0}
 			EPATCH_SOURCE=${EPATCH_SOURCE} \
 			EPATCH_SUFFIX="patch" \
 			EPATCH_FORCE="yes" \
 			EPATCH_MULTI_MSG="Applying user patches from ${EPATCH_SOURCE} ..." \
 			epatch
 			echo "${EPATCH_SOURCE}" > "${applied}"
-			has epatch_user_death_notice ${EBUILD_DEATH_HOOKS} || EBUILD_DEATH_HOOKS+=" epatch_user_death_notice"
+			if [[ ${old_n_applied_patches} -lt ${EPATCH_N_APPLIED_PATCHES} ]]; then
+				has epatch_user_death_notice ${EBUILD_DEATH_HOOKS} || \
+					EBUILD_DEATH_HOOKS+=" epatch_user_death_notice"
+			fi
 			return 0
 		fi
 	done