From f4707a8041181133c92b2beca88a39ec92137e19 Mon Sep 17 00:00:00 2001
From: "L. E. Segovia" <13498015+amyspark@users.noreply.github.com>
Date: Sat, 12 Oct 2019 15:53:21 +0000
Subject: [PATCH 1/2] upgrade: reject formulae checked in earlier levels

---
 Library/Homebrew/cmd/upgrade.rb | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/Library/Homebrew/cmd/upgrade.rb b/Library/Homebrew/cmd/upgrade.rb
index e1488c2fd7..1797f872cb 100644
--- a/Library/Homebrew/cmd/upgrade.rb
+++ b/Library/Homebrew/cmd/upgrade.rb
@@ -255,7 +255,7 @@ module Homebrew
     [formulae_to_upgrade, formulae_pinned]
   end
 
-  def broken_dependents(kegs, formulae)
+  def broken_dependents(kegs, formulae, scanned = [])
     formulae_to_reinstall = Set.new
     formulae_pinned_and_outdated = Set.new
 
@@ -266,6 +266,8 @@ module Homebrew
         dependents = kegs.select do |keg|
           keg.runtime_dependencies
              .any? { |d| d["full_name"] == formula.full_name }
+        end.reject do |keg|
+          scanned.include?(keg)
         end
 
         next if dependents.empty?
@@ -290,7 +292,9 @@ module Homebrew
           descendants << f
         end
 
-        descendants_to_reinstall, descendants_pinned = broken_dependents(kegs, descendants)
+        scanned << dependents
+
+        descendants_to_reinstall, descendants_pinned = broken_dependents(kegs, descendants, scanned)
 
         formulae_to_reinstall.merge descendants_to_reinstall
         formulae_pinned_and_outdated.merge descendants_pinned

From 024007f9e280c544475f3b74228aaf2b28ece43b Mon Sep 17 00:00:00 2001
From: "L. E. Segovia" <13498015+amyspark@users.noreply.github.com>
Date: Sat, 12 Oct 2019 22:06:08 +0000
Subject: [PATCH 2/2] upgrade: address @MikeMcQuaid's comments

---
 Library/Homebrew/cmd/upgrade.rb | 11 +++++------
 1 file changed, 5 insertions(+), 6 deletions(-)

diff --git a/Library/Homebrew/cmd/upgrade.rb b/Library/Homebrew/cmd/upgrade.rb
index 1797f872cb..781f425425 100644
--- a/Library/Homebrew/cmd/upgrade.rb
+++ b/Library/Homebrew/cmd/upgrade.rb
@@ -255,7 +255,7 @@ module Homebrew
     [formulae_to_upgrade, formulae_pinned]
   end
 
-  def broken_dependents(kegs, formulae, scanned = [])
+  def broken_dependents(kegs, formulae, scanned = Set.new)
     formulae_to_reinstall = Set.new
     formulae_pinned_and_outdated = Set.new
 
@@ -264,10 +264,9 @@ module Homebrew
         descendants = Set.new
 
         dependents = kegs.select do |keg|
-          keg.runtime_dependencies
-             .any? { |d| d["full_name"] == formula.full_name }
-        end.reject do |keg|
-          scanned.include?(keg)
+          keg = keg.runtime_dependencies
+                   .any? { |d| d["full_name"] == formula.full_name }
+          keg unless scanned.include?(keg)
         end
 
         next if dependents.empty?
@@ -292,7 +291,7 @@ module Homebrew
           descendants << f
         end
 
-        scanned << dependents
+        scanned.merge dependents
 
         descendants_to_reinstall, descendants_pinned = broken_dependents(kegs, descendants, scanned)