From 05293c33334f6e403b92b2a5d7381858c0bfca1d Mon Sep 17 00:00:00 2001
From: Ed Morley <501702+edmorley@users.noreply.github.com>
Date: Mon, 9 Aug 2021 22:11:43 +0100
Subject: [PATCH] Make Check Changelog compatible with actions/checkout v2
 (#135)

The GitHub action `actions/checkout` now only shallow clones the Git
repo as of v2+, meaning the Check Changelog action fails with:
`fatal: ambiguous argument 'remotes/origin/main': unknown revision or path not in the working tree.`

To fix, an explicit `git fetch` has been added of the HEAD of the default branch.

In addition, the event types on which the check is run has been updated
to include missing event types:
https://docs.github.com/en/actions/reference/events-that-trigger-workflows#pull_request

Refs GUS-W-9728468.
---
 .github/workflows/check_changelog.yml | 8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

diff --git a/.github/workflows/check_changelog.yml b/.github/workflows/check_changelog.yml
index 66c03c9d..99a0b11f 100644
--- a/.github/workflows/check_changelog.yml
+++ b/.github/workflows/check_changelog.yml
@@ -2,10 +2,10 @@ name: Check Changelog
 
 on:
   pull_request:
-    types: [opened, reopened, edited, synchronize, labeled]
+    types: [opened, reopened, edited, labeled, unlabeled, synchronize]
 
 jobs:
-  check:
+  check-changelog:
     runs-on: ubuntu-latest
     if: |
       !contains(github.event.pull_request.body, '[skip changelog]') &&
@@ -15,4 +15,6 @@ jobs:
     steps:
       - uses: actions/checkout@v2.3.4
       - name: Check that CHANGELOG is touched
-        run: git diff remotes/origin/${{ github.base_ref }} --name-only | grep CHANGELOG.md
+        run: |
+          git fetch origin ${{ github.base_ref }} --depth 1 && \
+          git diff remotes/origin/${{ github.base_ref }} --name-only | grep CHANGELOG.md