From f624ed09abba4a0bae64eb699c9fc2e3f9bdc2dc Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Rafael=20Mendon=C3=A7a=20Fran=C3=A7a?= <rafael@franca.dev>
Date: Thu, 24 Sep 2020 22:41:04 +0000
Subject: [PATCH] Don't make rexml an dependency of activesupport

rexml is only used in the xml_mini backend and it should be the users
choice if they want to use that feature or not. If they do we will warn
them that installing rexml is needed like we do with all backends.
---
 Gemfile                                            |  1 +
 Gemfile.lock                                       |  2 +-
 activesupport/activesupport.gemspec                |  1 -
 activesupport/lib/active_support/xml_mini/rexml.rb | 10 +++++++++-
 4 files changed, 11 insertions(+), 3 deletions(-)

diff --git a/Gemfile b/Gemfile
index e5c0ebcbed..a58e183a00 100644
--- a/Gemfile
+++ b/Gemfile
@@ -48,6 +48,7 @@ gem "dalli"
 gem "listen", "~> 3.2", require: false, github: "guard/listen"
 gem "libxml-ruby", platforms: :ruby
 gem "connection_pool", require: false
+gem "rexml", require: false
 
 # for railties app_generator_test
 gem "bootsnap", ">= 1.4.4", require: false
diff --git a/Gemfile.lock b/Gemfile.lock
index 336c64155b..69630d0e2e 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -95,7 +95,6 @@ PATH
       concurrent-ruby (~> 1.0, >= 1.0.2)
       i18n (>= 1.6, < 2)
       minitest (>= 5.1)
-      rexml
       tzinfo (~> 2.0)
       zeitwerk (~> 2.3)
     rails (6.1.0.alpha)
@@ -607,6 +606,7 @@ DEPENDENCIES
   redis-namespace!
   resque
   resque-scheduler
+  rexml
   rouge
   rubocop (>= 0.90)
   rubocop-packaging
diff --git a/activesupport/activesupport.gemspec b/activesupport/activesupport.gemspec
index 9cffc2696c..72cd995f02 100644
--- a/activesupport/activesupport.gemspec
+++ b/activesupport/activesupport.gemspec
@@ -38,5 +38,4 @@
   s.add_dependency "concurrent-ruby", "~> 1.0", ">= 1.0.2"
   s.add_dependency "zeitwerk",        "~> 2.3"
   s.add_dependency "minitest",        ">= 5.1"
-  s.add_dependency "rexml"
 end
diff --git a/activesupport/lib/active_support/xml_mini/rexml.rb b/activesupport/lib/active_support/xml_mini/rexml.rb
index 8d6e3af066..626e0122ac 100644
--- a/activesupport/lib/active_support/xml_mini/rexml.rb
+++ b/activesupport/lib/active_support/xml_mini/rexml.rb
@@ -25,7 +25,7 @@ def parse(data)
       if data.eof?
         {}
       else
-        silence_warnings { require "rexml/document" } unless defined?(REXML::Document)
+        require_rexml unless defined?(REXML::Document)
         doc = REXML::Document.new(data)
 
         if doc.root
@@ -38,6 +38,14 @@ def parse(data)
     end
 
     private
+
+      def require_rexml
+        silence_warnings { require "rexml/document" }
+      rescue LoadError => e
+        $stderr.puts "You don't have rexml installed in your application. Please add it to your Gemfile and run bundle install"
+        raise e
+      end
+
       # Convert an XML element and merge into the hash
       #
       # hash::