add backporting git alias

git/gitconfig

@@ -31,6 +31,8 @@
     la = !git l --all
     sync = "!source ~/.githelpers && sync_to_remote"
     bsync = "!source ~/.githelpers && update_branch"
+    bp = !git backport
+    backport = "!source ~/.githelpers && backport_pr"
 
     todo = grep --heading --break --ignore-case -e ' FIX: *' -e ' TODO: *'
     pr = "!source ~/.githelpers && get_pr"

git/githelpers

@@ -87,4 +87,23 @@ clean_branches() {
     for i in ${BRANCHES}; do
         git branch -d $i
     done
-}
+}
+
+backport_pr() {
+    PR=$1
+    BRANCH=$2
+    [ -z "$BRANCH" ] && BRANCH=`git rev-parse --abbrev-ref HEAD`
+    REMOTE=$3
+    : ${REMOTE:=$DEFAULT_REMOTE}
+    THISBRANCH=`git rev-parse --abbrev-ref HEAD`
+
+    if [ -z "$PR" ]; then
+        echo "Please specify a PR to backport"
+        exit 1
+    fi
+
+    echo Backporting ${PR} to ${BRANCH} from ${REMOTE}
+    git fetch ${REMOTE} pull/${1}/head:pr/${1}
+    git checkout ${BRANCH} && curl -s "https://github.com/elastic/kibana/pull/${PR}.patch" | git am
+    [ "$THISBRANCH" != "$BRANCH" ] && git checkout -
+}