hack/update-vendor-licenses.sh: skip empty packages

Signed-off-by: Giuseppe Scrivano <gscrivan@redhat.com>

hack/update-vendor-licenses.sh

@@ -196,6 +196,20 @@ for PACKAGE in $(go list -m -json all | jq -r .Path | sort -f); do
     echo "${PACKAGE} doesn't exist in ${DEPS_DIR}, skipping" >&2
     continue
   fi
+  # Skip a directory if 1) it has no files and 2) all the subdirectories contain a go.mod file.
+  if [[ -z "$(find "${DEPS_DIR}/${PACKAGE}" -mindepth 1 -maxdepth 1 -type f)" ]]; then
+      misses_go_mod=false
+      while read -d "" -r SUBDIR; do
+          if [[ ! -e "${SUBDIR}/go.mod" ]]; then
+              misses_go_mod=true
+              break
+          fi
+      done < <(find "${DEPS_DIR}/${PACKAGE}" -mindepth 1 -maxdepth 1 -type d -print0)
+      if [[ $misses_go_mod = false ]]; then
+          echo "${PACKAGE} has no files, skipping" >&2
+          continue
+      fi
+  fi
   echo "${PACKAGE}"
 
   process_content "${PACKAGE}" LICENSE