Add check-restored-packages pre-commit hook

Signed-off-by: Łukasz 'sil2100' Zemczak <lukasz.zemczak@chainguard.dev>

Author: sil2100

.pre-commit-hooks.yaml

@@ -20,3 +20,12 @@
     - manual
   types:
     - yaml
+- id: check-restored-packages
+  name: Check restored packages against withdrawn
+  description: Ensures packages being added to restored-packages.txt are removed from withdrawn-packages.txt first
+  entry: scripts/check-restored-packages.sh
+  language: script
+  stages:
+    - pre-commit
+    - manual
+  files: ^restored-packages\.txt$

scripts/check-restored-packages.sh

@@ -0,0 +1,37 @@
+#!/bin/bash
+set -e
+
+# Check if restored-packages.txt is being modified
+if ! git diff --cached --name-only | grep -q "restored-packages.txt"; then
+    exit 0
+fi
+
+if [ ! -f "withdrawn-packages.txt" ] || [ ! -f "restored-packages.txt" ]; then
+    exit 0
+fi
+
+# Get the new lines being added to restored-packages.txt
+NEW_PACKAGES=$(git diff --cached "restored-packages.txt" | grep "^+" | grep -v "^+++" | sed 's/^+//' | grep -v '^$' | grep -v '^#')
+
+if [ -z "$NEW_PACKAGES" ]; then
+    exit 0
+fi
+
+# Check if any new packages are in withdrawn-packages.txt
+CONFLICTS=""
+while IFS= read -r package; do
+    if [ -n "$package" ]; then
+        if grep -Fxq "$package" "withdrawn-packages.txt"; then
+            CONFLICTS="${CONFLICTS}${package}\n"
+        fi
+    fi
+done <<< "$NEW_PACKAGES"
+
+if [ -n "$CONFLICTS" ]; then
+    echo "ERROR: The following packages are being added to restored-packages.txt but are still present in withdrawn-packages.txt:"
+    echo -e "$CONFLICTS"
+    echo "Please remove these packages from withdrawn-packages.txt first, then commit again."
+    exit 1
+fi
+
+exit 0