[ruby/rdoc] Remove `RDoc::RI::Driver#in_path?`

https://github.com/ruby/rdoc/commit/83051403d6

lib/rdoc/ri/driver.rb

@@ -1141,17 +1141,6 @@ or the PAGER environment variable.
     exit
   end
 
-  ##
-  # Is +file+ in ENV['PATH']?
-
-  def in_path? file
-    return true if file =~ %r%\A/% and File.exist? file
-
-    ENV['PATH'].split(File::PATH_SEPARATOR).any? do |path|
-      File.exist? File.join(path, file)
-    end
-  end
-
   ##
   # Lists classes known to ri starting with +names+.  If +names+ is empty all
   # known classes are shown.

test/rdoc/test_rdoc_ri_driver.rb

@@ -1091,23 +1091,6 @@ Foo::Bar#bother
     assert_instance_of @RM::ToBs, driver.formatter(StringIO.new)
   end
 
-  def test_in_path_eh
-    path = ENV['PATH']
-
-    test_path = File.expand_path '..', __FILE__
-
-    temp_dir do |dir|
-      nonexistent = File.join dir, 'nonexistent'
-      refute @driver.in_path?(nonexistent)
-
-      ENV['PATH'] = test_path
-
-      assert @driver.in_path?(File.basename(__FILE__))
-    end
-  ensure
-    ENV['PATH'] = path
-  end
-
   def test_method_type
     assert_equal :both,     @driver.method_type(nil)
     assert_equal :both,     @driver.method_type('.')