Handle more failure edge cases in update.sh

.template-helpers/generate-dockerfile-links-partial.sh

@@ -12,6 +12,11 @@ IFS=$'\n'
 lines=( $(curl -fsSL 'https://raw.githubusercontent.com/docker-library/official-images/master/library/'"$repo" | grep -vE '^$|^#') )
 unset IFS
 
+if [ "${#lines[@]}" -eq 0 ]; then
+	echo >&2 "Failed to read manifest file for $repo"
+	exit 1
+fi
+
 repoDirs=()
 declare -A repoDirTags=()
 

update.sh

@@ -109,7 +109,9 @@ for repo in "${repos[@]}"; do
 		cp -v "$helperDir/template.md" "$repo/README.md"
 		
 		echo '  TAGS => generate-dockerfile-links-partial.sh'
-		replace_field "$repo" 'TAGS' "$("$helperDir/generate-dockerfile-links-partial.sh" "$repo")"
+		partial="$("$helperDir/generate-dockerfile-links-partial.sh" "$repo")"
+		[ "$partial" ]
+		replace_field "$repo" 'TAGS' "$partial"
 		
 		echo '  CONTENT => '"$repo"'/content.md'
 		replace_field "$repo" 'CONTENT' "$(cat "$repo/content.md")"