citemplate: Allow spaces in filenames when indenting

Part-of: <https://gitlab.freedesktop.org/gstreamer/gst-ci/-/merge_requests/328>

gitlab/ci_template.yml

@@ -359,19 +359,19 @@ gst indent:
     # man indent. grep RETURN VALUE, grab a beer on my behalf...
     - indent --version || true
     - |
-      filter_cmd="cat"
+      filter_cmd=("cat")
       if test -f ".indentignore"; then
-          filter_args=""
+          filter_args=()
           while read -r line; do
               if test -n "$line"; then
-                  filter_args="$filter_args -e $line"
+                  filter_args+=("-e" "$line")
               fi
           done < ".indentignore"
-          if test -n "$filter_args"; then
-              filter_cmd="grep -v $filter_args"
+          if [[ ${#filter_args[@]} -gt 0 ]]; then
+              filter_cmd=("grep" "-v" "${filter_args[@]}")
           fi
       fi
-      find . -name '*.c' | $filter_cmd | xargs gst-indent
+      find . -name '*.c' | "${filter_cmd[@]}" | xargs -d '\n' gst-indent
     - |
       if git diff --quiet; then
           echo "Code is properly formatted"