From 587f338daabfd7ee5f02bff8fc976a0d32e13c2b Mon Sep 17 00:00:00 2001
From: Misty De Meo <mistydemeo@gmail.com>
Date: Mon, 29 May 2017 21:48:12 -0700
Subject: [PATCH] vendor-install: use Ruby as a sha256 fallback

But still prefer shasum/sha256sum where present.
---
 Library/Homebrew/cmd/vendor-install.sh | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/Library/Homebrew/cmd/vendor-install.sh b/Library/Homebrew/cmd/vendor-install.sh
index 46f0c72f9d..fe7e26dd44 100644
--- a/Library/Homebrew/cmd/vendor-install.sh
+++ b/Library/Homebrew/cmd/vendor-install.sh
@@ -82,6 +82,15 @@ fetch() {
   elif [[ -x "$(which sha256sum)" ]]
   then
     sha="$(sha256sum "$CACHED_LOCATION" | cut -d' ' -f1)"
+  elif [[ -x "$(which ruby)" ]]
+  then
+    sha="$(ruby <<EOSCRIPT
+            require 'digest/sha2'
+            digest = Digest::SHA256.new
+            File.open('$CACHED_LOCATION', 'rb') { |f| digest.update(f.read) }
+            puts digest.hexdigest
+EOSCRIPT
+)"
   else
     odie "Cannot verify the checksum ('shasum' or 'sha256sum' not found)!"
   fi