From 5f3b113092f30ea52f45858650f87f122117e031 Mon Sep 17 00:00:00 2001
From: Antony Lee <anntzer.lee@gmail.com>
Date: Wed, 10 Nov 2021 23:36:28 +0100
Subject: [PATCH] Check for added-and-modified images in a given PR.

---
 .github/workflows/clean_pr.yml | 12 +++++++++++-
 1 file changed, 11 insertions(+), 1 deletion(-)

diff --git a/.github/workflows/clean_pr.yml b/.github/workflows/clean_pr.yml
index fc2acc0b2e4c..18af5253d58d 100644
--- a/.github/workflows/clean_pr.yml
+++ b/.github/workflows/clean_pr.yml
@@ -19,4 +19,14 @@ jobs:
             printf 'The following files were both added and deleted in this PR:\n%s\n' "$ad"
             exit 1
           fi
-
+      - name: Check for added-and-modified images
+        run: |
+          git fetch --quiet origin "$GITHUB_BASE_REF"
+          base="$(git merge-base "origin/$GITHUB_BASE_REF" 'HEAD^2')"
+          am="$(git log "$base..HEAD^2" --pretty=tformat: --name-status --diff-filter=AM |
+                cut --fields 2 | sort | uniq --repeated |
+                grep -E '.(png|pdf|ps|eps|svg)' || true)"
+          if [[ -n "$am" ]]; then
+            printf 'The following images were both added and modified in this PR:\n%s\n' "$am"
+            exit 1
+          fi