Fix & Deprecate REXML::Text#text_indent (#275)

- Fixes #273 
- "Fix" in the sense that it restores the original behavior pre-v3.2.6,
  regardless of its fitness for purpose.
- Regression Test Added

---------

Co-authored-by: Sutou Kouhei <[email protected]>

Author: pboling

lib/rexml/child.rb

@@ -88,7 +88,7 @@ def document
 
     # This doesn't yet handle encodings
     def bytes
-      document.encoding
+      document&.encoding
 
       to_s
     end

lib/rexml/text.rb

@@ -269,8 +269,10 @@ def wrap(string, width, addnewline=false)
     end
 
     def indent_text(string, level=1, style="\t", indentfirstline=true)
+      Kernel.warn("#{self.class.name}#indent_text is deprecated. See REXML::Formatters", uplevel: 1)
       return string if level < 0
-      new_string = ''
+
+      new_string = +''
       string.each_line { |line|
         indent_string = style * level
         new_line = (indent_string + line).sub(/[\s]+$/,'')

test/test_text.rb

@@ -2,6 +2,7 @@
 
 module REXMLTests
   class TextTester < Test::Unit::TestCase
+    include Helper::Global
     include REXML
 
     def test_new_text_response_whitespace_default
@@ -69,5 +70,12 @@ def test_clone
       assert_equal(text.to_s,
                    text.clone.to_s)
     end
+
+    def test_indent_text
+      text = Text.new("")
+      suppress_warning do
+        assert_equal("\tline1\tline2\tline3", text.indent_text("line1\r\nline2\r\nline3\r\n"))
+      end
+    end
   end
 end