From 93ec28f68b6c04f6c31bc8e117b586ef1a469331 Mon Sep 17 00:00:00 2001
From: Watson <watson1978@gmail.com>
Date: Fri, 19 Jul 2024 14:36:19 +0900
Subject: [PATCH] Raise ParseException with proper message

---
 lib/rexml/parsers/baseparser.rb       | 6 +++++-
 test/parse/test_entity_declaration.rb | 9 ++++++++-
 2 files changed, 13 insertions(+), 2 deletions(-)

diff --git a/lib/rexml/parsers/baseparser.rb b/lib/rexml/parsers/baseparser.rb
index 5688c773..87c904cf 100644
--- a/lib/rexml/parsers/baseparser.rb
+++ b/lib/rexml/parsers/baseparser.rb
@@ -318,7 +318,11 @@ def pull_event
               raise REXML::ParseException.new( "Bad ELEMENT declaration!", @source ) if md.nil?
               return [ :elementdecl, "<!ELEMENT" + md[1] ]
             elsif @source.match("ENTITY", true)
-              match = [:entitydecl, *@source.match(Private::ENTITYDECL_PATTERN, true, term: Private::ENTITY_TERM).captures.compact]
+              scanner = @source.match(Private::ENTITYDECL_PATTERN, true, term: Private::ENTITY_TERM)
+              unless scanner
+                raise REXML::ParseException.new("Malformed entity declaration", @source)
+              end
+              match = [:entitydecl, *scanner.captures.compact]
               ref = false
               if match[1] == '%'
                 ref = true
diff --git a/test/parse/test_entity_declaration.rb b/test/parse/test_entity_declaration.rb
index 26f4b23f..72f26afe 100644
--- a/test/parse/test_entity_declaration.rb
+++ b/test/parse/test_entity_declaration.rb
@@ -24,11 +24,18 @@ def parse(internal_subset)
 
     public
     def test_empty
-      assert_raise(REXML::ParseException) do
+      exception = assert_raise(REXML::ParseException) do
         parse(<<-INTERNAL_SUBSET)
 <!ENTITY>
         INTERNAL_SUBSET
       end
+      assert_equal(<<-DETAIL.chomp, exception.to_s)
+Malformed entity declaration
+Line: 5
+Position: 70
+Last 80 unconsumed characters:
+>  ]> <r/> 
+      DETAIL
     end
 
     def test_linear_performance_gt