Do not invoke `destroy` hook for text nodes

snabbdom.js

@@ -90,11 +90,13 @@ function init(modules) {
 
   function invokeDestroyHook(vnode) {
     var i = vnode.data, j;
-    if (!isUndef(i) && !isUndef(i = i.hook) && !isUndef(i = i.destroy)) i(vnode);
-    for (i = 0; i < cbs.destroy.length; ++i) cbs.destroy[i](vnode);
-    if (!isUndef(i = vnode.children)) {
-      for (j = 0; j < vnode.children.length; ++j) {
-        invokeDestroyHook(vnode.children[j]);
+    if (!isUndef(i)) {
+      if (!isUndef(i = i.hook) && !isUndef(i = i.destroy)) i(vnode);
+      for (i = 0; i < cbs.destroy.length; ++i) cbs.destroy[i](vnode);
+      if (!isUndef(i = vnode.children)) {
+        for (j = 0; j < vnode.children.length; ++j) {
+          invokeDestroyHook(vnode.children[j]);
+        }
       }
     }
   }

test/core.js

@@ -656,6 +656,25 @@ describe('snabbdom', function() {
         assert.equal(created, 4);
         assert.equal(destroyed, 4);
       });
+      it('does not invoke `destroy` module hook for text nodes', function() {
+        var created = 0;
+        var destroyed = 0;
+        var patch = snabbdom.init([
+          {create: function() { created++; }},
+          {destroy: function() { destroyed++; }},
+        ]);
+        var vnode1 = h('div', [
+          h('span', 'First sibling'),
+          h('div', [
+            h('span', 'Child 1'),
+            h('span', ['Text 1', 'Text 2']),
+          ]),
+        ]);
+        patch(vnode0, vnode1);
+        patch(vnode1, vnode0);
+        assert.equal(created, 4);
+        assert.equal(destroyed, 4);
+      });
     });
   });
   describe('short circuiting', function() {