merge revision(s) ddb32e66160ab50849419ef7c7ac584913b79c34: [Backport #18173]

	[Bug #18173] Update loaded_features_index

	If $LOADED_FEATURES is changed in the just required file, also the
	index table needs to be updated before loaded_features_snapshot is
	reset.  If the snapshot is reset without updating the table, the
	name of the added feature will not be found.
	---
	 load.c                    |  1 +
	 test/ruby/test_require.rb | 17 +++++++++++++++++
	 2 files changed, 18 insertions(+)

1 files changed, 17 insertions, 0 deletions

diff --git a/test/ruby/test_require.rb b/test/ruby/test_require.rb
index 4c8faadbc7..52566ecbfb 100644
--- a/test/ruby/test_require.rb
+++ b/test/ruby/test_require.rb
@@ -839,6 +839,23 @@ class TestRequire < Test::Unit::TestCase
     }
   end
 
+  def test_provide_in_required_file
+    paths, loaded = $:.dup, $".dup
+    Dir.mktmpdir do |tmp|
+      provide = File.realdirpath("provide.rb", tmp)
+      File.write(File.join(tmp, "target.rb"), "raise __FILE__\n")
+      File.write(provide, '$" << '"'target.rb'\n")
+      $:.replace([tmp])
+      assert(require("provide"))
+      assert(!require("target"))
+      assert_equal($".pop, provide)
+      assert_equal($".pop, "target.rb")
+    end
+  ensure
+    $:.replace(paths)
+    $".replace(loaded)
+  end
+
   if defined?($LOAD_PATH.resolve_feature_path)
     def test_resolve_feature_path
       paths, loaded = $:.dup, $".dup