Script to set up upstreams as expected for safer pushes

CONTRIBUTING.md

@@ -421,6 +421,8 @@ $ git config remotes.upstreams
 upstream upstream-push
 ```
 
+You can use the [bin/git/setup-upstreams.sh] script to set this up.
+
 It also assumes you have a default gpg signing key set up in git. e.g.
 ```
 $ git config user.signingkey

bin/git/setup-upstreams.sh

@@ -0,0 +1,86 @@
+#!/bin/bash
+
+if [[ $# -ne 1 || "$1" == "--help" || "$1" == "-h" ]]
+then
+  name=$( basename $0 )
+  cat <<- USAGE
+	Usage: $name <username>
+	
+	Where <username> is the Github username of the upstream repo. e.g. XRPLF
+USAGE
+  exit 0
+fi
+
+# Create upstream remotes based on origin
+shift
+user="$1"
+# Get the origin URL. Expect it be an SSH-style URL
+origin=$( git remote get-url origin )
+if [[ "${origin}" == "" ]]
+then
+  echo Invalid origin remote >&2
+  exit 1
+fi
+# echo "Origin: ${origin}"
+# Parse the origin
+ifs_orig="${IFS}"
+IFS=':' read remote originpath <<< "${origin}"
+# echo "Remote: ${remote}, Originpath: ${originpath}"
+IFS='@' read sshuser server <<< "${remote}"
+# echo "SSHUser: ${sshuser}, Server: ${server}"
+IFS='/' read originuser repo <<< "${originpath}"
+# echo "Originuser: ${originuser}, Repo: ${repo}"
+if [[ "${sshuser}" == "" || "${server}" == "" || "${originuser}" == ""
+  || "${repo}" == "" ]]
+then
+  echo "Can't parse origin URL: ${origin}" >&2
+  exit 1
+fi
+upstream="https://${server}/${user}/${repo}"
+upstreampush="${remote}:${user}/${repo}"
+upstreamgroup="upstream upstream-push"
+current=$( git remote get-url upstream 2>/dev/null )
+currentpush=$( git remote get-url upstream-push 2>/dev/null )
+currentgroup=$( git config remotes.upstreams )
+if [[ "${current}" == "${upstream}" ]]
+then
+  echo "Upstream already set up correctly. Skip"
+elif [[ -n "${current}" && "${current}" != "${upstream}" &&
+  "${current}" != "${upstreampush}" ]]
+then
+  echo "Upstream already set up as: ${current}. Skip"
+else
+  if [[ "${current}" == "${upstreampush}" ]]
+  then
+    echo "Upstream set to dangerous push URL. Update."
+    _run git remote rename upstream upstream-push || \
+    _run git remote remove upstream
+    currentpush=$( git remote get-url upstream-push 2>/dev/null )
+  fi
+  _run git remote add upstream "${upstream}"
+fi
+
+if [[ "${currentpush}" == "${upstreampush}" ]]
+then
+  echo "Upstream-push already set up correctly. Skip"
+elif [[ -n "${currentpush}" && "${currentpush}" != "${upstreampush}" ]]
+then
+  echo "Upstream-push already set up as: ${currentpush}. Skip"
+else
+  _run git remote add upstream-push "${upstreampush}"
+fi
+
+if [[ "${currentgroup}" == "${upstreamgroup}" ]]
+then
+  echo "Upstreams group already set up correctly. Skip"
+elif [[ -n "${currentgroup}" && "${currentgroup}" != "${upstreamgroup}" ]]
+then
+  echo "Upstreams group already set up as: ${currentgroup}. Skip"
+else
+  _run git config --add remotes.upstreams "upstream upstream-push"
+fi
+
+_run git fetch --jobs=$(nproc) upstreams
+
+exit 0
+