From e7ac3489db5eec4e09c2e032d49bf10cfe0a711e Mon Sep 17 00:00:00 2001
From: Leo Arnold <github@leoarnold.de>
Date: Tue, 26 Aug 2025 21:49:13 +0200
Subject: [PATCH] Fix ParseError when String has no trailing newline character

---
 lib/rexml/source.rb   | 2 +-
 test/test_document.rb | 6 ++++++
 2 files changed, 7 insertions(+), 1 deletion(-)

diff --git a/lib/rexml/source.rb b/lib/rexml/source.rb
index 99500072..9677e1be 100644
--- a/lib/rexml/source.rb
+++ b/lib/rexml/source.rb
@@ -258,7 +258,7 @@ def read(term = nil, min_bytes = 1)
         end
         true
       rescue Exception, NameError
-        @source = nil
+        @source = StringIO.new
         false
       end
     end
diff --git a/test/test_document.rb b/test/test_document.rb
index 39b6c337..9632a709 100644
--- a/test/test_document.rb
+++ b/test/test_document.rb
@@ -159,6 +159,12 @@ def test_xml_declaration_standalone
       assert_equal('no', doc.stand_alone?, bug2539)
     end
 
+    def test_no_trailing_newline
+      assert_nothing_raised do
+        REXML::Document.new("<?xml version=\"1.0\"?>\n<!DOCTYPE coverage SYSTEM \"http://cobertura.sourceforge.net/xml/coverage-04.dtd\">\n<!-- Generated by simplecov-cobertura version 3.0.0 (https://github.com/jessebs/simplecov-cobertura) -->")
+      end
+    end
+
     def test_each_recursive
       xml_source = <<~XML
         <?xml version="1.0" encoding="UTF-8" standalone="yes"?>