Validate the info.xml file with a workflow

Signed-off-by: Joas Schilling <coding@schilljs.com>

.drone.yml

@@ -12,7 +12,7 @@ steps:
       - wget https://raw.githubusercontent.com/nextcloud/travis_ci/master/before_install.sh
       - bash ./before_install.sh $APP_NAME $CORE_BRANCH $DATABASEHOST
       - cd ../server
-      - sh -c "if [ $(./occ app:check-code $APP_NAME | wc -l) -ne 5 ]; then ./occ app:check-code $APP_NAME; fi"
+      - sh -c "if [ $(./occ app:check-code --skip-validate-info $APP_NAME | wc -l) -ne 5 ]; then ./occ app:check-code --skip-validate-info $APP_NAME; fi"
       - cd apps/$APP_NAME/
 
 trigger:

.github/workflows/lint.yml

@@ -87,3 +87,16 @@ jobs:
 
       - name: Lint
         run: npm run stylelint
+
+  xml-linters:
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout
+        uses: actions/checkout@master
+      - name: Download schema
+        run: wget https://apps.nextcloud.com/schema/apps/info.xsd
+      - name: Lint info.xml
+        uses: ChristophWurst/xmllint-action@v1
+        with:
+          xml-file: ./appinfo/info.xml
+          xml-schema-file: ./info.xsd