build: Backport "generate strictly increasing git revisions"

Enhance luci-0.12's build/mkrevision.sh by backporting
the code to generate strictly increasing git revisions:
https://github.com/openwrt/luci/commit/0856030c79f3febdafa627511cf1be4c72edf09b

Signed-off-by: Hannu Nyman <hannu.nyman@iki.fi>

diff --git a/build/mkrevision.sh b/build/mkrevision.sh
index 889ce75c24b1e2b1bf19f9c2ecea2bdc063d93c8..02b7fa3710dfffc8ab1f2d7fd7b7ebc2e9a58689 100755 (executable)
--- a/build/mkrevision.sh
+++ b/build/mkrevision.sh
@@ -14,7 +14,10 @@ TOPDIR="${0%mkrevision.sh}"
        elif git log -1 >/dev/null 2>/dev/null; then
                revision="svn-r$(LC_ALL=C git log -1 | sed -ne 's/.*git-svn-id: .*@\([0-9]\+\) .*/\1/p')"
                if [ "$revision" = "svn-r" ]; then
-                       revision="git-$(LC_ALL=C git log -1 --pretty=%h)"
+                       set -- $(git log -1 --format="%ct %h")
+                       secs="$(($1 % 86400))"
+                       yday="$(date --utc --date="@$1" "+%y.%j")"
+                       revision="$(printf 'git-%s.%05d-%s' "$yday" "$secs" "$2")"
                fi
        else
                revision="unknown"