From eaae52edb8c54658cc792cc9a300791c2ef03bad Mon Sep 17 00:00:00 2001
From: Mike McQuaid <mike@mikemcquaid.com>
Date: Thu, 14 Jan 2021 16:26:17 +0000
Subject: [PATCH] tab: return default values on existing, blank install receipt
 contents.

---
 Library/Homebrew/tab.rb | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/Library/Homebrew/tab.rb b/Library/Homebrew/tab.rb
index e7224ed1e8..29c1e7d511 100644
--- a/Library/Homebrew/tab.rb
+++ b/Library/Homebrew/tab.rb
@@ -58,7 +58,12 @@ class Tab < OpenStruct
   # Returns the {Tab} for an install receipt at `path`.
   # Results are cached.
   def self.from_file(path)
-    cache.fetch(path) { |p| cache[p] = from_file_content(File.read(p), p) }
+    cache.fetch(path) do |p|
+      content = File.read(p)
+      return empty if content.blank?
+
+      cache[p] = from_file_content(content, p)
+    end
   end
 
   # Like {from_file}, but bypass the cache.