From 26bcdbc7667b18bb3e3bd06eb009f5fb78ca418c Mon Sep 17 00:00:00 2001
From: "nicolas.dorier" <nicolas.dorier@gmail.com>
Date: Mon, 25 Oct 2021 14:55:58 +0900
Subject: [PATCH] Fix: Many SVG assets were not showing properly if rootpath is
 used

---
 BTCPayServer/TagHelpers.cs | 22 ++++++++++++++++++++++
 1 file changed, 22 insertions(+)

diff --git a/BTCPayServer/TagHelpers.cs b/BTCPayServer/TagHelpers.cs
index a938e4fe1..1f70d00af 100644
--- a/BTCPayServer/TagHelpers.cs
+++ b/BTCPayServer/TagHelpers.cs
@@ -4,6 +4,7 @@ using System.Globalization;
 using System.Linq;
 using System.Text;
 using System.Threading.Tasks;
+using BTCPayServer.Configuration;
 using BTCPayServer.Security;
 using BTCPayServer.Services;
 using Microsoft.AspNetCore.Razor.TagHelpers;
@@ -141,4 +142,25 @@ namespace BTCPayServer.TagHelpers
             }
         }
     }
+
+    // Make sure that <svg><use href=/ are correctly working if rootpath is present
+    [HtmlTargetElement("use", Attributes = "href")]
+    public class SVGUse : TagHelper
+    {
+        private string _RootPath;
+
+        public SVGUse(BTCPayServerOptions opts)
+        {
+            _RootPath = opts.RootPath;
+        }
+        public override void Process(TagHelperContext context, TagHelperOutput output)
+        {
+            if (string.IsNullOrEmpty(_RootPath) || _RootPath == "/")
+                return;
+            var attr = output.Attributes["href"];
+            if (!attr.Value.ToString().StartsWith("/", StringComparison.OrdinalIgnoreCase))
+                return;
+            output.Attributes.SetAttribute("href", $"{_RootPath}{attr.Value}");
+        }
+    }
 }