[FIX] hooks: useSubEnv will not erase previous useChildSubEnv

tests/components/__snapshots__/hooks.test.ts.snap

@@ -103,6 +103,37 @@ exports[`hooks mounted callbacks should be called in reverse order from willUnmo
 }"
 `;
 
+exports[`hooks parent and child env (with useChildSubEnv then useSubEnv) 1`] = `
+"function anonymous(bdom, helpers
+) {
+  let { text, createBlock, list, multi, html, toggler, component, comment } = bdom;
+  
+  return function template(ctx, node, key = \\"\\") {
+    let b2 = text(ctx['env'].val);
+    let b3 = component(\`Child\`, {}, key + \`__1\`, node, ctx);
+    return multi([b2, b3]);
+  }
+}"
+`;
+
+exports[`hooks parent and child env (with useChildSubEnv then useSubEnv) 2`] = `
+"function anonymous(bdom, helpers
+) {
+  let { text, createBlock, list, multi, html, toggler, component, comment } = bdom;
+  
+  let block2 = createBlock(\`<div><block-text-0/></div>\`);
+  
+  return function template(ctx, node, key = \\"\\") {
+    let b2;
+    if (ctx['env'].hasParent) {
+      let txt1 = ctx['env'].val;
+      b2 = block2([txt1]);
+    }
+    return multi([b2]);
+  }
+}"
+`;
+
 exports[`hooks parent and child env (with useChildSubEnv) 1`] = `
 "function anonymous(bdom, helpers
 ) {