fix: bad JSON state leaving events disabled (#7501)

* fix: broken JSON state stopping event firing

* chore: add unit test for events not breaking

Author: BeksOmega

core/serialization/blocks.ts

@@ -399,9 +399,13 @@ export function appendInternal(
   }
   eventUtils.disable();
 
-  const block = appendPrivate(state, workspace, {parentConnection, isShadow});
+  let block;
+  try {
+    block = appendPrivate(state, workspace, {parentConnection, isShadow});
+  } finally {
+    eventUtils.enable();
+  }
 
-  eventUtils.enable();
   if (eventUtils.isEnabled()) {
     eventUtils.fire(new (eventUtils.get(eventUtils.BLOCK_CREATE))(block));
   }

tests/mocha/jso_deserialization_test.js

@@ -23,6 +23,25 @@ suite('JSO Deserialization', function () {
   });
 
   suite('Events', function () {
+    test('bad JSON does not leave events disabled', function () {
+      const state = {
+        'blocks': {
+          'blocks': [
+            {
+              'type': 'undefined_block',
+            },
+          ],
+        },
+      };
+      chai.assert.throws(() => {
+        Blockly.serialization.workspaces.load(state, this.workspace);
+      });
+      chai.assert.isTrue(
+        Blockly.Events.isEnabled(),
+        'Expected events to be enabled',
+      );
+    });
+
     suite('Finished loading', function () {
       test('Just var', function () {
         const state = {