From cf5e85995224ffe15c38c665103e7055b447f7b1 Mon Sep 17 00:00:00 2001
From: SimonShiki <sinangentoo@gmail.com>
Date: Tue, 11 Aug 2026 16:11:48 +0800
Subject: [PATCH] :bug: fix(vm): keep obcursed menu dropdown shadow

Signed-off-by: SimonShiki <sinangentoo@gmail.com>
---
 packages/vm/src/serialization/sb2.js          |  1 +
 .../fixtures/obscured-dropdown-shadow.json    | 26 +++++++++++
 packages/vm/test/unit/engine_adapter.js       | 44 +++++++++++++++++++
 packages/vm/test/unit/serialization_sb2.js    | 28 ++++++++++++
 4 files changed, 99 insertions(+)
 create mode 100644 packages/vm/test/fixtures/obscured-dropdown-shadow.json

diff --git a/packages/vm/src/serialization/sb2.js b/packages/vm/src/serialization/sb2.js
index c6c4c10b..3deefef7 100644
--- a/packages/vm/src/serialization/sb2.js
+++ b/packages/vm/src/serialization/sb2.js
@@ -952,6 +952,7 @@ const parseBlock = function (sb2block, addBroadcastMsg, getVariableId, extension
         inputs: {}, // Inputs to this block and the blocks they point to.
         fields: {}, // Fields on this block and their values.
         next: null, // Next block.
+        topLevel: false, // Nested blocks are not script roots.
         shadow: false, // No shadow blocks in an SB2 by default.
         children: [] // Store any generated children, flattened in `flatten`.
     };
diff --git a/packages/vm/test/fixtures/obscured-dropdown-shadow.json b/packages/vm/test/fixtures/obscured-dropdown-shadow.json
new file mode 100644
index 00000000..2b990c15
--- /dev/null
+++ b/packages/vm/test/fixtures/obscured-dropdown-shadow.json
@@ -0,0 +1,26 @@
+{
+    "projectVersion": 2,
+    "objName": "Stage",
+    "variables": [
+        {
+            "name": "costume name",
+            "value": "costume1"
+        }
+    ],
+    "lists": [],
+    "scripts": [
+        [
+            80,
+            60,
+            [
+                [
+                    "lookLike:",
+                    ["getVar:", "costume name"]
+                ]
+            ]
+        ]
+    ],
+    "costumes": [],
+    "sounds": [],
+    "children": []
+}
diff --git a/packages/vm/test/unit/engine_adapter.js b/packages/vm/test/unit/engine_adapter.js
index ec42613c..84016376 100644
--- a/packages/vm/test/unit/engine_adapter.js
+++ b/packages/vm/test/unit/engine_adapter.js
@@ -170,6 +170,50 @@ test('create with obscured shadow', t => {
     t.end();
 });
 
+test('create from state keeps an obscured shadow nested', t => {
+    const result = adapter({
+        json: [{
+            id: 'switch-costume',
+            type: 'looks_switchcostumeto',
+            inputs: {
+                COSTUME: {
+                    block: {
+                        id: 'variable-reporter',
+                        type: 'data_variable',
+                        fields: {
+                            VARIABLE: {
+                                id: 'costume-name',
+                                name: 'costume name'
+                            }
+                        }
+                    },
+                    shadow: {
+                        id: 'costume-shadow',
+                        type: 'looks_costume',
+                        fields: {
+                            COSTUME: 'COSTUME1'
+                        }
+                    }
+                }
+            }
+        }]
+    });
+
+    t.equal(result.length, 3);
+    t.equal(result.filter(block => block.topLevel).length, 1);
+    const parent = result.find(block => block.id === 'switch-costume');
+    const variableReporter = result.find(block => block.id === 'variable-reporter');
+    const shadow = result.find(block => block.id === 'costume-shadow');
+    t.equal(parent.topLevel, true);
+    t.equal(parent.inputs.COSTUME.block, variableReporter.id);
+    t.equal(parent.inputs.COSTUME.shadow, shadow.id);
+    t.equal(variableReporter.shadow, false);
+    t.equal(variableReporter.topLevel, false);
+    t.equal(shadow.shadow, true);
+    t.equal(shadow.topLevel, false);
+    t.end();
+});
+
 test('create variable with entity in name', t => {
     const result = adapter(events.createvariablewithentity);
 
diff --git a/packages/vm/test/unit/serialization_sb2.js b/packages/vm/test/unit/serialization_sb2.js
index 5552b759..e5c07f42 100644
--- a/packages/vm/test/unit/serialization_sb2.js
+++ b/packages/vm/test/unit/serialization_sb2.js
@@ -4,6 +4,7 @@ import {extractProjectJson} from '../fixtures/readProjectFile.js';
 import RenderedTarget from '../../src/sprites/rendered-target';
 import Runtime from '../../src/engine/runtime';
 import {deserialize} from '../../src/serialization/sb2.js';
+import obscuredDropdownShadow from '../fixtures/obscured-dropdown-shadow.json';
 
 test('spec', t => {
     t.type(deserialize, 'function');
@@ -100,3 +101,30 @@ test('Ordering', t => {
         t.end();
     });
 });
+
+test('obscured dropdown shadow keeps the variable reporter as the input block', t => {
+    const runtime = new Runtime();
+
+    return deserialize(obscuredDropdownShadow, runtime).then(({targets}) => {
+        const blocks = targets[0].blocks;
+        const switchCostume = blocks.getBlock(blocks.getScripts()[0]);
+        const input = switchCostume.inputs.COSTUME;
+        const variableReporter = blocks.getBlock(input.block);
+        const shadow = blocks.getBlock(input.shadow);
+
+        t.equal(switchCostume.opcode, 'looks_switchcostumeto');
+        t.equal(variableReporter.opcode, 'data_variable');
+        t.equal(variableReporter.shadow, false);
+        t.equal(variableReporter.topLevel, false);
+        t.equal(shadow.opcode, 'looks_costume');
+        t.equal(shadow.shadow, true);
+        t.equal(shadow.topLevel, false);
+        t.ok(input.block !== input.shadow);
+
+        const state = blocks.toState();
+        const stateInput = state[0].inputs.COSTUME;
+        t.equal(stateInput.block.type, 'data_variable');
+        t.equal(stateInput.shadow.type, 'looks_costume');
+        t.end();
+    });
+});