fix: ensure SVG namespaces are correct when copying a thunk

ISSUES CLOSED: #867

src/h.ts

@@ -13,17 +13,19 @@ export type VNodeChildElement =
 export type ArrayOrElement<T> = T | T[];
 export type VNodeChildren = ArrayOrElement<VNodeChildElement>;
 
-function addNS(
+export function addNS(
   data: any,
-  children: VNodes | undefined,
+  children: Array<VNode | string> | undefined,
   sel: string | undefined
 ): void {
   data.ns = "http://www.w3.org/2000/svg";
   if (sel !== "foreignObject" && children !== undefined) {
     for (let i = 0; i < children.length; ++i) {
-      const childData = children[i].data;
+      const child = children[i];
+      if (typeof child === "string") continue;
+      const childData = child.data;
       if (childData !== undefined) {
-        addNS(childData, children[i].children as VNodes, children[i].sel);
+        addNS(childData, child.children as VNodes, child.sel);
       }
     }
   }

src/thunk.ts

@@ -1,5 +1,5 @@
 import { VNode, VNodeData } from "./vnode";
-import { h } from "./h";
+import { h, addNS } from "./h";
 
 export interface ThunkData extends VNodeData {
   fn: () => VNode;
@@ -16,12 +16,14 @@ export interface ThunkFn {
 }
 
 function copyToThunk(vnode: VNode, thunk: VNode): void {
+  const ns = thunk.data ? thunk.data.ns : null;
   (vnode.data as VNodeData).fn = (thunk.data as VNodeData).fn;
   (vnode.data as VNodeData).args = (thunk.data as VNodeData).args;
   thunk.data = vnode.data;
   thunk.children = vnode.children;
   thunk.text = vnode.text;
   thunk.elm = vnode.elm;
+  if (ns) addNS(thunk.data, thunk.children, thunk.sel);
 }
 
 function init(thunk: VNode): void {