Moves shared helper scripts to the buildroot

buildroot/share/git/mfup

@@ -0,0 +1,53 @@
+#!/usr/bin/env bash
+#
+# mfup
+#
+# Fetch and merge upstream changes, optionally with a branch
+#
+
+MFINFO=$(mfinfo) || exit
+
+IFS=' ' read -a INFO <<< "$MFINFO"
+
+ORG=${INFO[0]}
+FORK=${INFO[1]}
+REPO=${INFO[2]}
+TARG=${INFO[3]}
+OLDBRANCH=${INFO[4]}
+
+if [[ $OLDBRANCH == "(no" ]]; then
+  echo "Branch is unavailable!"
+  exit 1
+fi
+
+case "$#" in
+  0 ) BRANCH=$OLDBRANCH ;;
+  1 ) BRANCH=$1 ;;
+  * ) echo "Usage: `basename $0` [branch]" 1>&2 ; exit 1 ;;
+esac
+
+set -e
+
+echo "Fetching upstream ($ORG/$REPO)..."
+git fetch upstream
+
+echo ; echo "Bringing $TARG up to date..."
+git checkout -q $TARG || git branch checkout upstream/$TARG -b $TARG && git push --set-upstream origin $TARG
+git merge upstream/$TARG
+git push origin
+
+if [[ $BRANCH != $TARG ]]; then
+  echo ; echo "Rebasing $BRANCH on $TARG..."
+  if git checkout $BRANCH; then
+    echo
+    if git rebase $TARG; then
+      git push -f ; echo
+      [[ $BRANCH != $OLDBRANCH ]] && git checkout $OLDBRANCH
+    else
+      echo "Looks like merge conflicts. Stopping here."
+    fi
+  else
+    echo "No such branch!" ; echo
+    git checkout $OLDBRANCH
+  fi
+fi