`make makepatch`: Don't replace patches with only metadata changes

Rather than replacing patches that are effectively the same but with
different timestamps, drop the new version and let the old version remain in
place. This yields a `make makepatch` that doesn't try and produce unwanted
churn.

Approved by:	portmgr (mat)
Differential Revision:	https://reviews.freebsd.org/D13960

1 files changed, 33 insertions, 0 deletions

diff --git a/Mk/Scripts/smart_makepatch.sh b/Mk/Scripts/smart_makepatch.sh
index b84416b235d1..41f96e5e6399 100644
--- a/Mk/Scripts/smart_makepatch.sh
+++ b/Mk/Scripts/smart_makepatch.sh
@@ -230,6 +230,38 @@ stage_patches() {
 	done
 }
 
+compare_common_patches() {
+	[ -z "${old_patch_list}" ] && return
+	local archive_patch_list
+	local P
+	local ppatch
+	local ppatch_stripped
+	local cpatch
+	local cpatch_stripped
+	for P in ${old_patch_list}; do
+		if [ -e ${DESTDIR}/${P} ]; then
+			ppatch=${PATCHDIR}/${P}
+			cpatch=${DESTDIR}/${P}
+			ppatch_stripped=$(mktemp -t portpatch)
+			cpatch_stripped=$(mktemp -t portpatch)
+			egrep -v -- '--- .+ UTC$' ${ppatch} \
+				> ${ppatch_stripped}
+			egrep -v -- '--- .+ UTC$' ${cpatch} \
+				> ${cpatch_stripped}
+			# Don't replace patches with only metadata changes
+			if ! cmp -s ${ppatch_stripped} ${cpatch_stripped}; then
+				archive_patch_list="${archive_patch_list} ${P}"
+			else
+				echo "${P} only contains metadata changes; not replacing"
+				rm ${cpatch}
+			fi
+			rm ${ppatch_stripped}
+			rm ${cpatch_stripped}
+		fi
+	done
+	old_patch_list=${archive_patch_list}
+}
+
 conserve_old_patches() {
 	mkdir -p ${SAVEDIR}
 	rm -f ${SAVEDIR}/*
@@ -257,5 +289,6 @@ map_existing_patches
 extract_comments
 regenerate_patches
 stage_patches
+compare_common_patches
 conserve_old_patches
 install_regenerated_patches