From 9d1902be19d305961505fa938f7acb8bbacf673e Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Rafael=20Mendon=C3=A7a=20Fran=C3=A7a?=
 <rafaelmfranca@gmail.com>
Date: Fri, 5 Jun 2020 12:38:32 -0400
Subject: [PATCH] Only digest the environment version if it is not blank

---
 lib/sprockets/asset.rb | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/lib/sprockets/asset.rb b/lib/sprockets/asset.rb
index bb204b854..28267a227 100644
--- a/lib/sprockets/asset.rb
+++ b/lib/sprockets/asset.rb
@@ -135,7 +135,13 @@ def hexdigest
 
     # Pubic: ETag String of Asset.
     def etag
-      DigestUtils.hexdigest(environment_version.to_s + digest)
+      version = environment_version
+
+      if version && version != ""
+        DigestUtils.hexdigest(version + digest)
+      else
+        DigestUtils.pack_hexdigest(digest)
+      end
     end
 
     # Public: Returns String base64 digest of source.