ci: Fix detecting changed files

.github/workflows/test-import.yml

@@ -10,10 +10,10 @@ jobs:
     runs-on: ubuntu-latest
     steps:
     - name: Check out code
-      uses: actions/checkout@v3
-    - name: Fetch submodules
-      run: git submodule update --init --checkout --remote
+      uses: actions/checkout@v4
+    - name: Fetch branches and submodules
+      run: git fetch --unshallow && git fetch --all && git submodule update --init --checkout --remote
     - name: Build docker images
       run: docker build -t transitous . -f ci/container/Containerfile
-    - name: Verify that new feeds can be downloaded
+    - name: Verify that new feeds can be downloaded and parsed
       run: docker run -v $PWD:/transitous -w /transitous transitous ci/fetch-feeds.py merge-request

ci/fetch-feeds.py

@@ -4,6 +4,7 @@
 # SPDX-License-Identifier: AGPL-3.0-or-later
 
 import sys
+import os
 from pathlib import Path
 import subprocess
 
@@ -20,9 +21,16 @@
         for feed in feed_dir.glob("*.json"):
             subprocess.check_call(["./src/fetch.py", str(feed.absolute())])
     case "merge-request":
+        # Silence warnings about different ownerships inside and outside of the
+        # container on actions
+        subprocess.check_call(
+            ["git", "config", "--global",
+             "--add", "safe.directory", os.getcwd()])
+
+        # Find all files that were changed in the latest commit
         changed_files = subprocess.check_output(
-            ["git", "diff", "--name-only", "-r", "HEAD^1", "HEAD"]) \
-                .decode().splitlines()
+            ["git", "diff", "--name-only", "origin/main", "HEAD"]) \
+            .decode().splitlines()
 
         changed_feeds = [f for f in changed_files if
                          f.startswith("feeds/") and f.endswith(".json")]