Adds html parser check for void elements

OpenDreamClient/Interface/Html/HtmlParser.cs

@@ -84,7 +84,8 @@ void PushCurrentText() {
                     } else {
                         tags.Push(tagType);
 
-                        appendTo.PushTag(new MarkupNode(tagType, null, ParseAttributes(attributes)), selfClosing: attributes[^1] == "/");
+                        bool isSelfClosing = IsSelfClosing(tagType, attributes);
+                        appendTo.PushTag(new MarkupNode(tagType, null, ParseAttributes(attributes)), selfClosing: isSelfClosing);
                     }
 
                     break;
@@ -139,6 +140,39 @@ void PushCurrentText() {
             appendTo.Pop();
     }
 
+    /**
+     * <summary>
+     * Returns if a tag is written in old self-closing form, or if the tag
+     * represents a void element, which must have no children
+     * </summary>
+     */
+    private static bool IsSelfClosing(string tagType, string[] attributes) {
+        if (attributes[^1] == "/") {
+            return true;
+        }
+
+        switch (tagType) {
+            case "area":
+            case "base":
+            case "br":
+            case "col":
+            case "embed":
+            case "hr":
+            case "img":
+            case "input":
+            case "link":
+            case "meta":
+            case "param":
+            case "source":
+            case "track":
+            case "wbr":
+                return true;
+
+            default:
+                return false;
+        }
+    }
+
     private static Dictionary<string, MarkupParameter> ParseAttributes(string[] attributes) {
         Dictionary<string, MarkupParameter> parsedAttributes = new();