[ruby/resolv] Fix invalid "Broken registry" warning for UseDomainNameDevolution

This value is dword, not a string.

Amends https://github.com/ruby/resolv/commit/720e25034042.

https://github.com/ruby/resolv/commit/bf00ed8585

2 files changed, 116 insertions, 6 deletions

diff --git a/ext/win32/lib/win32/resolv.rb b/ext/win32/lib/win32/resolv.rb
index ef74a890bb..43ec10cf98 100644
--- a/ext/win32/lib/win32/resolv.rb
+++ b/ext/win32/lib/win32/resolv.rb
@@ -83,7 +83,7 @@ module Win32
 
           unless nvdom.empty?
             search = [ nvdom ]
-            udmnd = get_item_property(TCPIP_NT, 'UseDomainNameDevolution').to_i
+            udmnd = get_item_property(TCPIP_NT, 'UseDomainNameDevolution', dword: true)
             if udmnd != 0
               if /^\w+\./ =~ nvdom
                 devo = $'
@@ -126,17 +126,23 @@ module Win32
         [ search.uniq, nameserver.uniq ]
       end
 
-      def get_item_property(path, name, expand: false)
+      def get_item_property(path, name, expand: false, dword: false)
         if defined?(Win32::Registry)
-          Registry::HKEY_LOCAL_MACHINE.open(path) do |reg|
-            expand ? reg.read_s_expand(name) : reg.read_s(name)
+          begin
+            Registry::HKEY_LOCAL_MACHINE.open(path) do |reg|
+              if dword
+                reg.read_i(name)
+              else
+                expand ? reg.read_s_expand(name) : reg.read_s(name)
+              end
+            end
           rescue Registry::Error
-            ""
+            dword ? 0 : ""
           end
         else
           cmd = "Get-ItemProperty -Path 'HKLM:\\#{path}' -Name '#{name}' -ErrorAction SilentlyContinue | Select-Object -ExpandProperty '#{name}'"
           output, _ = Open3.capture2('powershell', '-Command', cmd)
-          output.strip
+          dword ? output.strip.to_i : output.strip
         end
       end
     end
diff --git a/test/resolv/test_win32_config.rb b/test/resolv/test_win32_config.rb
new file mode 100644
index 0000000000..f44d19544a
--- /dev/null
+++ b/test/resolv/test_win32_config.rb
@@ -0,0 +1,104 @@
+# frozen_string_literal: true
+
+require 'test/unit'
+require 'resolv'
+
+class TestWin32Config < Test::Unit::TestCase
+  def setup
+    omit 'Win32::Resolv tests only run on Windows' unless RUBY_PLATFORM =~ /mswin|mingw|cygwin/
+  end
+
+  def test_get_item_property_string
+    # Test reading a string registry value
+    result = Win32::Resolv.send(:get_item_property,
+                                Win32::Resolv::TCPIP_NT,
+                                'DataBasePath')
+
+    # Should return a string (empty or with a path)
+    assert_instance_of String, result
+  end
+
+  def test_get_item_property_with_expand
+    # Test reading an expandable string registry value
+    result = Win32::Resolv.send(:get_item_property,
+                                Win32::Resolv::TCPIP_NT,
+                                'DataBasePath',
+                                expand: true)
+
+    # Should return a string with environment variables expanded
+    assert_instance_of String, result
+  end
+
+  def test_get_item_property_dword
+    # Test reading a DWORD registry value
+    result = Win32::Resolv.send(:get_item_property,
+                                Win32::Resolv::TCPIP_NT,
+                                'UseDomainNameDevolution',
+                                dword: true)
+
+    # Should return an integer (0 or 1 typically)
+    assert_kind_of Integer, result
+  end
+
+  def test_get_item_property_nonexistent_key
+    # Test reading a non-existent registry key
+    result = Win32::Resolv.send(:get_item_property,
+                                Win32::Resolv::TCPIP_NT,
+                                'NonExistentKeyThatShouldNotExist')
+
+    # Should return empty string for non-existent string values
+    assert_equal '', result
+  end
+
+  def test_get_item_property_nonexistent_key_dword
+    # Test reading a non-existent registry key as DWORD
+    result = Win32::Resolv.send(:get_item_property,
+                                Win32::Resolv::TCPIP_NT,
+                                'NonExistentKeyThatShouldNotExist',
+                                dword: true)
+
+    # Should return 0 for non-existent DWORD values
+    assert_equal 0, result
+  end
+
+  def test_get_item_property_search_list
+    # Test reading SearchList which may exist in the registry
+    result = Win32::Resolv.send(:get_item_property,
+                                Win32::Resolv::TCPIP_NT,
+                                'SearchList')
+
+    # Should return a string (may be empty if not configured)
+    assert_instance_of String, result
+  end
+
+  def test_get_item_property_nv_domain
+    # Test reading NV Domain which may exist in the registry
+    result = Win32::Resolv.send(:get_item_property,
+                                Win32::Resolv::TCPIP_NT,
+                                'NV Domain')
+
+    # Should return a string (may be empty if not configured)
+    assert_instance_of String, result
+  end
+
+  def test_get_item_property_with_invalid_path
+    # Test with an invalid registry path
+    result = Win32::Resolv.send(:get_item_property,
+                                'SYSTEM\NonExistent\Path',
+                                'SomeKey')
+
+    # Should return empty string for invalid path
+    assert_equal '', result
+  end
+
+  def test_get_item_property_with_invalid_path_dword
+    # Test with an invalid registry path as DWORD
+    result = Win32::Resolv.send(:get_item_property,
+                                'SYSTEM\NonExistent\Path',
+                                'SomeKey',
+                                dword: true)
+
+    # Should return 0 for invalid path
+    assert_equal 0, result
+  end
+end