fix #4852, break some other stuff

src/compiler/compile/render_dom/wrappers/RawMustacheTag.ts

@@ -53,8 +53,8 @@ export default class RawMustacheTagWrapper extends Tag {
 
 			const update_anchor = in_head ? 'null' : needs_anchor ? html_anchor : this.next ? this.next.var : 'null';
 
-			block.chunks.hydrate.push(b`${html_tag} = new @HtmlTag(${init}, ${update_anchor});`);
-			block.chunks.mount.push(b`${html_tag}.m(${parent_node || '#target'}, ${parent_node ? null : '#anchor'});`);
+			block.chunks.hydrate.push(b`${html_tag} = new @HtmlTag(${update_anchor});`);
+			block.chunks.mount.push(b`${html_tag}.m(${init}, ${parent_node || '#target'}, ${parent_node ? null : '#anchor'});`);
 
 			if (needs_anchor) {
 				block.add_element(html_anchor, x`@empty()`, x`@empty()`, parent_node);

src/runtime/internal/dom.ts

@@ -319,29 +319,31 @@ export class HtmlTag {
 	t: HTMLElement;
 	a: HTMLElement;
 
-	constructor(html: string, anchor: HTMLElement = null) {
-		this.e = element('div');
+	constructor(anchor: HTMLElement = null) {
 		this.a = anchor;
-		this.u(html);
 	}
 
-	m(target: HTMLElement, anchor: HTMLElement = null) {
-		for (let i = 0; i < this.n.length; i += 1) {
-			insert(target, this.n[i], anchor);
+	m(html: string, target: HTMLElement, anchor: HTMLElement = null) {
+		if (!this.e) {
+			this.e = element(target.nodeName as keyof HTMLElementTagNameMap);
+			this.t = target;
 		}
 
-		this.t = target;
+		this.u(html, anchor);
 	}
 
-	u(html: string) {
+	u(html: string, anchor) {
 		this.e.innerHTML = html;
 		this.n = Array.from(this.e.childNodes);
+
+		for (let i = 0; i < this.n.length; i += 1) {
+			insert(this.t, this.n[i], anchor);
+		}
 	}
 
 	p(html: string) {
 		this.d();
-		this.u(html);
-		this.m(this.t, this.a);
+		this.u(html, this.a);
 	}
 
 	d() {