From cddf88730f570f8249f81d9da68c69932e6f336b Mon Sep 17 00:00:00 2001
From: DHR60 <dehongren60@gmail.com>
Date: Tue, 26 Aug 2025 17:34:12 +0800
Subject: [PATCH] Fix dns (#7834)

---
 .../CoreConfig/Singbox/SingboxDnsService.cs   | 52 ++++++++-----------
 .../CoreConfig/V2ray/V2rayDnsService.cs       | 48 +++++++----------
 2 files changed, 39 insertions(+), 61 deletions(-)

diff --git a/v2rayN/ServiceLib/Services/CoreConfig/Singbox/SingboxDnsService.cs b/v2rayN/ServiceLib/Services/CoreConfig/Singbox/SingboxDnsService.cs
index 15f2c43b..2f0f8015 100644
--- a/v2rayN/ServiceLib/Services/CoreConfig/Singbox/SingboxDnsService.cs
+++ b/v2rayN/ServiceLib/Services/CoreConfig/Singbox/SingboxDnsService.cs
@@ -80,25 +80,31 @@ public partial class CoreConfigSingboxService
             hostsDns.predefined = Global.PredefinedHosts;
         }
 
+        if (simpleDNSItem.UseSystemHosts == true)
+        {
+            var systemHosts = Utils.GetSystemHosts();
+            if (systemHosts != null && systemHosts.Count > 0)
+            {
+                foreach (var host in systemHosts)
+                {
+                    hostsDns.predefined.TryAdd(host.Key, new List<string> { host.Value });
+                }
+            }
+        }
+
         if (!simpleDNSItem.Hosts.IsNullOrEmpty())
         {
-            var userHostsMap = simpleDNSItem.Hosts?
+            var userHostsMap = simpleDNSItem.Hosts
                 .Split(new[] { '\r', '\n' }, StringSplitOptions.RemoveEmptyEntries)
-                .Where(line => !string.IsNullOrWhiteSpace(line))
-                .Where(line => line.Contains(' '))
+                .Select(line => line.Trim())
+                .Where(line => !string.IsNullOrWhiteSpace(line) && line.Contains(' '))
+                .Select(line => line.Split(new[] { ' ', '\t' }, StringSplitOptions.RemoveEmptyEntries))
+                .Where(parts => parts.Length >= 2)
+                .GroupBy(parts => parts[0])
                 .ToDictionary(
-                    line =>
-                    {
-                        var parts = line.Trim().Split(new[] { ' ', '\t' }, StringSplitOptions.RemoveEmptyEntries);
-                        return parts[0];
-                    },
-                    line =>
-                    {
-                        var parts = line.Trim().Split(new[] { ' ', '\t' }, StringSplitOptions.RemoveEmptyEntries);
-                        var values = parts.Skip(1).ToList();
-                        return values;
-                    }
-                ) ?? new Dictionary<string, List<string>>();
+                    group => group.Key,
+                    group => group.SelectMany(parts => parts.Skip(1)).ToList()
+                );
 
             foreach (var kvp in userHostsMap)
             {
@@ -106,22 +112,6 @@ public partial class CoreConfigSingboxService
             }
         }
 
-        if (simpleDNSItem.UseSystemHosts == true)
-        {
-            var systemHosts = Utils.GetSystemHosts();
-            if (systemHosts.Count > 0)
-            {
-                foreach (var host in systemHosts)
-                {
-                    if (hostsDns.predefined[host.Key] != null)
-                    {
-                        continue;
-                    }
-                    hostsDns.predefined[host.Key] = new List<string> { host.Value };
-                }
-            }
-        }
-
         foreach (var host in hostsDns.predefined)
         {
             if (finalDns.server == host.Key)
diff --git a/v2rayN/ServiceLib/Services/CoreConfig/V2ray/V2rayDnsService.cs b/v2rayN/ServiceLib/Services/CoreConfig/V2ray/V2rayDnsService.cs
index 9faf4df3..6f64e923 100644
--- a/v2rayN/ServiceLib/Services/CoreConfig/V2ray/V2rayDnsService.cs
+++ b/v2rayN/ServiceLib/Services/CoreConfig/V2ray/V2rayDnsService.cs
@@ -248,43 +248,31 @@ public partial class CoreConfigV2rayService
         if (simpleDNSItem.UseSystemHosts == true)
         {
             var systemHosts = Utils.GetSystemHosts();
-            if (systemHosts.Count > 0)
+            var normalHost = v2rayConfig?.dns?.hosts;
+
+            if (normalHost != null && systemHosts?.Count > 0)
             {
-                var normalHost = v2rayConfig.dns.hosts;
-                if (normalHost != null)
+                foreach (var host in systemHosts)
                 {
-                    foreach (var host in systemHosts)
-                    {
-                        if (normalHost[host.Key] != null)
-                        {
-                            continue;
-                        }
-                        normalHost[host.Key] = new List<string> { host.Value };
-                    }
+                    normalHost.TryAdd(host.Key, new List<string> { host.Value });
                 }
             }
         }
 
-        var userHostsMap = simpleDNSItem.Hosts?
-            .Split(new[] { '\r', '\n' }, StringSplitOptions.RemoveEmptyEntries)
-            .Where(line => !string.IsNullOrWhiteSpace(line))
-            .Where(line => line.Contains(' '))
-            .ToDictionary(
-                line =>
-                {
-                    var parts = line.Trim().Split(new[] { ' ', '\t' }, StringSplitOptions.RemoveEmptyEntries);
-                    return parts[0];
-                },
-                line =>
-                {
-                    var parts = line.Trim().Split(new[] { ' ', '\t' }, StringSplitOptions.RemoveEmptyEntries);
-                    var values = parts.Skip(1).ToList();
-                    return values;
-                }
-            );
-
-        if (userHostsMap != null)
+        if (!simpleDNSItem.Hosts.IsNullOrEmpty())
         {
+            var userHostsMap = simpleDNSItem.Hosts
+                .Split(new[] { '\r', '\n' }, StringSplitOptions.RemoveEmptyEntries)
+                .Select(line => line.Trim())
+                .Where(line => !string.IsNullOrWhiteSpace(line) && line.Contains(' '))
+                .Select(line => line.Split(new[] { ' ', '\t' }, StringSplitOptions.RemoveEmptyEntries))
+                .Where(parts => parts.Length >= 2)
+                .GroupBy(parts => parts[0])
+                .ToDictionary(
+                    group => group.Key,
+                    group => group.SelectMany(parts => parts.Skip(1)).ToList()
+                );
+
             foreach (var kvp in userHostsMap)
             {
                 v2rayConfig.dns.hosts[kvp.Key] = kvp.Value;