1 files changed, 38 insertions, 0 deletions
diff --git a/lib/bundler/environment_preserver.rb b/lib/bundler/environment_preserver.rb
new file mode 100644
index 0000000000..a891f4854d
--- /dev/null
+++ b/lib/bundler/environment_preserver.rb
@@ -0,0 +1,38 @@
+# frozen_string_literal: true
+module Bundler
+  class EnvironmentPreserver
+    # @param env [ENV]
+    # @param keys [Array<String>]
+    def initialize(env, keys)
+      @original = env.to_hash
+      @keys = keys
+      @prefix = "BUNDLER_ORIG_"
+    end
+
+    # @return [Hash]
+    def backup
+      env = @original.clone
+      @keys.each do |key|
+        value = env[key]
+        original_value = env[@prefix + key]
+        if !value.nil? && !value.empty? && original_value.nil?
+          env[@prefix + key] = value
+        end
+      end
+      env
+    end
+
+    # @return [Hash]
+    def restore
+      env = @original.clone
+      @keys.each do |key|
+        value_original = env[@prefix + key]
+        unless value_original.nil? || value_original.empty?
+          env[key] = value_original
+          env.delete(@prefix + key)
+        end
+      end
+      env
+    end
+  end
+end