From 769a6cd1f5631624aa934eaa0c9b3b2d66d85180 Mon Sep 17 00:00:00 2001
From: Bo Anderson <mail@boanderson.me>
Date: Wed, 10 Mar 2021 04:46:39 +0000
Subject: [PATCH] Don't touch PATH, GEM_HOME and GEM_PATH when testing formula

---
 Library/Homebrew/dev-cmd/test.rb |  2 +-
 Library/Homebrew/utils/gems.rb   | 13 ++++++++++++-
 Library/Homebrew/utils/gems.rbi  |  4 ++--
 3 files changed, 15 insertions(+), 4 deletions(-)

diff --git a/Library/Homebrew/dev-cmd/test.rb b/Library/Homebrew/dev-cmd/test.rb
index a18e6472049b1..ccf5922536a95 100644
--- a/Library/Homebrew/dev-cmd/test.rb
+++ b/Library/Homebrew/dev-cmd/test.rb
@@ -35,7 +35,7 @@ def test_args
   def test
     args = test_args.parse
 
-    Homebrew.install_bundler_gems!
+    Homebrew.install_bundler_gems!(setup_path: false)
 
     require "formula_assertions"
     require "formula_free_port"
diff --git a/Library/Homebrew/utils/gems.rb b/Library/Homebrew/utils/gems.rb
index 90b296b5a1f64..e607da5422d2d 100644
--- a/Library/Homebrew/utils/gems.rb
+++ b/Library/Homebrew/utils/gems.rb
@@ -125,7 +125,11 @@ def install_bundler!
     )
   end
 
-  def install_bundler_gems!(only_warn_on_failure: false)
+  def install_bundler_gems!(only_warn_on_failure: false, setup_path: true)
+    old_path = ENV["PATH"]
+    old_gem_path = ENV["GEM_PATH"]
+    old_gem_home = ENV["GEM_HOME"]
+
     install_bundler!
 
     ENV["BUNDLE_GEMFILE"] = File.join(ENV.fetch("HOMEBREW_LIBRARY"), "Homebrew", "Gemfile")
@@ -152,5 +156,12 @@ def install_bundler_gems!(only_warn_on_failure: false)
     end
 
     setup_gem_environment!
+  ensure
+    unless setup_path
+      # Reset the paths. We need to have at least temporarily changed them while invoking `bundle`.
+      ENV["PATH"] = old_path
+      ENV["GEM_PATH"] = old_gem_path
+      ENV["GEM_HOME"] = old_gem_home
+    end
   end
 end
diff --git a/Library/Homebrew/utils/gems.rbi b/Library/Homebrew/utils/gems.rbi
index 0aad66513887a..55bdcc1114cd9 100644
--- a/Library/Homebrew/utils/gems.rbi
+++ b/Library/Homebrew/utils/gems.rbi
@@ -22,6 +22,6 @@ module Homebrew
   sig { void }
   def install_bundler!; end
 
-  sig { params(only_warn_on_failure: T::Boolean).void }
-  def install_bundler_gems!(only_warn_on_failure: false); end
+  sig { params(only_warn_on_failure: T::Boolean, setup_path: T::Boolean).void }
+  def install_bundler_gems!(only_warn_on_failure: false, setup_path: false); end
 end