misc: Add checkout-pr.sh script for easier checkout

It usually takes some time to get patches for review but it'd be useful
to have a script for that.

The 'checkout-pr.sh' script accepts a single parameter to get the pull
request ID.
It fetches from the source repo and checkouts to the fetched head.

The example usage is as follows.

  $ ./misc/checkout-pr.sh 1974
    % Total    % Received % Xferd  Average Speed   Time    Time     Time  Current
                                   Dload  Upload   Total   Spent    Left  Speed
  100 18502  100 18502    0     0  39899      0 --:--:-- --:--:-- --:--:-- 39875
  remote: Enumerating objects: 1, done.
  remote: Counting objects: 100% (1/1), done.
  remote: Total 1 (delta 0), reused 1 (delta 0), pack-reused 0 (from 0)
  Unpacking objects: 100% (1/1), 354 bytes | 354.00 KiB/s, done.
  From https://github.com/GabrielKimm/uftrace
   * branch              fix-tui-non-utf8-locale -> FETCH_HEAD
  Switched to and reset branch 'pull/1974'

Now you're ready to review the pull request 1974 where can be found at
namhyung#1974.

Signed-off-by: Honggyu Kim <[email protected]>

misc/checkout-pr.sh

@@ -0,0 +1,20 @@
+#!/bin/sh
+
+if [ $# -ne "1" ]; then
+	echo "usage: $0 <PR number>"
+	exit 1
+fi
+
+if [ ! -x "$(command -v curl)" ]; then
+	echo "You need curl to run this script."
+	exit 1
+fi
+
+pr=$1
+pr_json="pr.json"
+
+curl -o $pr_json https://api.github.com/repos/namhyung/uftrace/pulls/$pr
+repo=$(jq -r '.head.repo.html_url' $pr_json)
+refspec=$(jq -r '.head.ref' $pr_json)
+git fetch $repo $refspec && git checkout -B pull/$pr FETCH_HEAD
+exit 0