From ba9f7fc08de13ab602cfd698295879853fdba0a8 Mon Sep 17 00:00:00 2001
From: NAITOH Jun <naitoh@gmail.com>
Date: Sun, 14 Jan 2024 21:48:27 +0900
Subject: [PATCH] Change `@scanner.match` to respond `nil`/`@scanner` in order
 to improve processing speed.

---
 lib/rexml/parsers/baseparser.rb |  3 +--
 lib/rexml/source.rb             | 17 ++++++++---------
 test/test_document.rb           | 12 ++++++++++++
 3 files changed, 21 insertions(+), 11 deletions(-)

diff --git a/lib/rexml/parsers/baseparser.rb b/lib/rexml/parsers/baseparser.rb
index 5ce7b8d9..65bad260 100644
--- a/lib/rexml/parsers/baseparser.rb
+++ b/lib/rexml/parsers/baseparser.rb
@@ -274,8 +274,7 @@ def pull_event
             return [ :elementdecl, @source.match( ELEMENTDECL_PATTERN, true )[1] ]
 
           when ENTITY_START
-            match = @source.match( ENTITYDECL, true ).compact
-            match[0] = :entitydecl
+            match = [:entitydecl, *@source.match( ENTITYDECL, true ).captures.compact]
             ref = false
             if match[1] == '%'
               ref = true
diff --git a/lib/rexml/source.rb b/lib/rexml/source.rb
index fafe270b..b9b94c7e 100644
--- a/lib/rexml/source.rb
+++ b/lib/rexml/source.rb
@@ -70,11 +70,10 @@ def read
 
     def match(pattern, cons=false)
       if cons
-        @scanner.scan(pattern)
+        @scanner.scan(pattern).nil? ? nil : @scanner
       else
-        @scanner.check(pattern)
+        @scanner.check(pattern).nil? ? nil : @scanner
       end
-      @scanner.matched? ? [@scanner.matched, *@scanner.captures] : nil
     end
 
     # @return true if the Source is exhausted
@@ -158,24 +157,24 @@ def read
 
     def match( pattern, cons=false )
       if cons
-        @scanner.scan(pattern)
+        md = @scanner.scan(pattern)
       else
-        @scanner.check(pattern)
+        md = @scanner.check(pattern)
       end
-      while !@scanner.matched? and @source
+      while md.nil? and @source
         begin
           @scanner << readline
           if cons
-            @scanner.scan(pattern)
+            md = @scanner.scan(pattern)
           else
-            @scanner.check(pattern)
+            md = @scanner.check(pattern)
           end
         rescue
           @source = nil
         end
       end
 
-      @scanner.matched? ? [@scanner.matched, *@scanner.captures] : nil
+      md.nil? ? nil : @scanner
     end
 
     def empty?
diff --git a/test/test_document.rb b/test/test_document.rb
index cca67df2..785b493b 100644
--- a/test/test_document.rb
+++ b/test/test_document.rb
@@ -173,6 +173,18 @@ def test_empty_value
             REXML::Document.new(xml)
           end
         end
+
+        def test_empty_entity
+          xml = <<EOF
+<!DOCTYPE root [
+  <!ENTITY>
+]>
+EOF
+
+          assert_raise(REXML::ParseException) do
+            REXML::Document.new(xml)
+          end
+        end
       end
     end