From f13e3b8e2ab071aa5b4c5b11c40d5cca2bde9c95 Mon Sep 17 00:00:00 2001
From: Lars Kanis <lars@greiz-reinsdorf.de>
Date: Mon, 25 Dec 2023 14:23:47 +0100
Subject: [PATCH] Remove .irbrc file on rubies >= 3.3

It is no longer necessary, since the enabled extensions have been made defaults in ruby core.
So ruby-3.3 uses the irb_predefiner to cleanup a previously generated .irbrc from the users home directory, so that the error output due to changed require paths is avoided.
Previously the outdated .irbrc led to an error like so:

$ irb
Error loading RC file 'C:/Users/Administrator/.irbrc':
<internal:C:/Ruby33-x64/lib/ruby/3.3.0/rubygems/core_ext/kernel_require.rb>:127:in `require': cannot load such file -- irb/ext/save-history (LoadError)
Did you mean?  irb/ext/eval_history
        from <internal:C:/Ruby33-x64/lib/ruby/3.3.0/rubygems/core_ext/kernel_require.rb>:127:in `require'
        from C:/Users/Administrator/.irbrc:1:in `<top (required)>'
        from C:/Ruby33-x64/lib/ruby/3.3.0/irb/init.rb:399:in `load'
---
 recipes/sandbox/20-extend-irb.rake  |  4 ++++
 resources/files/irbrc_predefiner.rb | 32 +++++++++++++++++++----------
 2 files changed, 25 insertions(+), 11 deletions(-)

diff --git a/recipes/sandbox/20-extend-irb.rake b/recipes/sandbox/20-extend-irb.rake
index 0a6b13e66..1255e4bba 100644
--- a/recipes/sandbox/20-extend-irb.rake
+++ b/recipes/sandbox/20-extend-irb.rake
@@ -1,3 +1,7 @@
+# This adds some logic to define a .irbrc to enable history saving and completion.
+# These features are enabled by default since ruby-3.3 and require paths have been changed.
+# Therefore the job on later versions is inverted to remove the .irbrc when unchanged.
+
 self.import_files.merge!({
   "resources/files/irbrc_predefiner.rb" => "lib/ruby/site_ruby/#{package.rubylibver}/irbrc_predefiner.rb",
 })
diff --git a/resources/files/irbrc_predefiner.rb b/resources/files/irbrc_predefiner.rb
index 3c8bc3c5b..6f603b801 100644
--- a/resources/files/irbrc_predefiner.rb
+++ b/resources/files/irbrc_predefiner.rb
@@ -2,20 +2,30 @@
 
 irbrc_file = IRB.enum_for(:rc_file_generators).first.call(IRB::IRBRC_EXT)
 
-if irbrc_file && !File.exist?(irbrc_file) && File.exist?(File.dirname(irbrc_file))
-  File.write irbrc_file, <<-EOT
+irbrc_text = <<-EOT
 require 'irb/ext/save-history'
 require 'irb/completion'
 IRB.conf[:SAVE_HISTORY] = 200
-  EOT
-end
+EOT
+
+if RUBY_VERSION < "3.3"
+  # Create a .irbrc file with default options on older rubies
+  if irbrc_file && !File.exist?(irbrc_file) && File.exist?(File.dirname(irbrc_file))
+    File.write irbrc_file, irbrc_text
+  end
 
-# Try to convert .irb_history from locale to UTF-8, if it isn't encoded properly.
-# This is for transition from CP* encodings of RbReadline to UTF-8 of Reline.
-history_file = IRB.rc_file("_history")
-if File.exist?(history_file) && !(hist=File.read(history_file, encoding: 'utf-8')).valid_encoding?
-  hist = hist.encode('utf-8', Encoding.find("locale"))
-  if hist.valid_encoding?
-    File.write(history_file, hist)
+  # Try to convert .irb_history from locale to UTF-8, if it isn't encoded properly.
+  # This is for transition from CP* encodings of RbReadline to UTF-8 of Reline.
+  history_file = IRB.rc_file("_history")
+  if File.exist?(history_file) && !(hist=File.read(history_file, encoding: 'utf-8')).valid_encoding?
+    hist = hist.encode('utf-8', Encoding.find("locale"))
+    if hist.valid_encoding?
+      File.write(history_file, hist)
+    end
+  end
+else
+  # Remove the now unnecessary .irbrc file when unchanged on newer rubies
+  if irbrc_file && File.exist?(irbrc_file) && File.read(irbrc_file) == irbrc_text
+    File.unlink irbrc_file
   end
 end