[source] scripts/getver.sh: improve revision output

[LEDE Commits]

jogo pushed a commit to source.git, branch master:
https://git.lede-project.org/?p=source.git;a=commitdiff;h=15b88df87f28faf4b37c8490c8e3af3fe1e4c0cb

commit 15b88df87f28faf4b37c8490c8e3af3fe1e4c0cb
Author: Jonas Gorski <jonas.gorski at gmail.com>
AuthorDate: Sat Jun 25 14:23:30 2016 +0200

    scripts/getver.sh: improve revision output
    
    Change the revision output to r<upstream-revision>+<local commits> so
    it is easier to get the base revision (and see if there are local
    commits).
    
    Example:
    $ ./scripts/getver.sh
    r794+3
    $
    
    Signed-off-by: Jonas Gorski <jonas.gorski at gmail.com>
---
 scripts/getver.sh | 9 +++++++--
 1 file changed, 7 insertions(+), 2 deletions(-)

diff --git a/scripts/getver.sh b/scripts/getver.sh
index a60b91e..4c8fab0 100755
--- a/scripts/getver.sh
+++ b/scripts/getver.sh
@@ -23,9 +23,14 @@ try_git() {
 		REV="$(git rev-parse HEAD~$((BASE_REV - GET_REV)))"
 		;;
 	*)
-
+		UPSTREAM_BASE="$(git merge-base $GET_REV origin/master)"
+		UPSTREAM_REV="$(git rev-list reboot..$UPSTREAM_BASE --count)"
 		REV="$(git rev-list reboot..$GET_REV --count)"
-		REV="${REV:+r$REV}"
+		if [ -n "$REV" -a -n "$UPSTREAM_REV" -a "$REV" -gt "$UPSTREAM_REV" ]; then
+			REV="r${UPSTREAM_REV}+$((REV - UPSTREAM_REV))"
+		else
+			REV="${REV:+r$REV}"
+		fi
 		;;
 	esac