From 52d935c815e9f7eed6871bd01cbbd1d97c48e23e Mon Sep 17 00:00:00 2001
From: Aaron Dodson <adodson@google.com>
Date: Mon, 12 Jan 2026 15:57:00 -0800
Subject: [PATCH] fix: Fix bug that prevented deleting a variable referenced by
 two connected blocks (#9563)

* fix: Fix bug that prevented deleting a variable referenced by two connected blocks

* fix: Remove inadvertent .only
---
 core/connection.ts                   |  5 +++-
 core/variable_map.ts                 |  2 ++
 tests/mocha/blocks/variables_test.js | 34 ++++++++++++++++++++++++++++
 3 files changed, 40 insertions(+), 1 deletion(-)

diff --git a/core/connection.ts b/core/connection.ts
index a79b7b9b1..a55c25059 100644
--- a/core/connection.ts
+++ b/core/connection.ts
@@ -291,7 +291,10 @@ export class Connection {
     }
 
     let event;
-    if (eventUtils.isEnabled()) {
+    if (
+      eventUtils.isEnabled() &&
+      !childConnection.getSourceBlock().isDeadOrDying()
+    ) {
       event = new (eventUtils.get(EventType.BLOCK_MOVE))(
         childConnection.getSourceBlock(),
       ) as BlockMove;
diff --git a/core/variable_map.ts b/core/variable_map.ts
index 3a6cf4026..88c28cbc3 100644
--- a/core/variable_map.ts
+++ b/core/variable_map.ts
@@ -315,6 +315,8 @@ export class VariableMap
     }
     try {
       for (let i = 0; i < uses.length; i++) {
+        if (uses[i].isDeadOrDying()) continue;
+
         uses[i].dispose(true);
       }
       const variables = this.variableMap.get(variable.getType());
diff --git a/tests/mocha/blocks/variables_test.js b/tests/mocha/blocks/variables_test.js
index 066de52b8..724e2e543 100644
--- a/tests/mocha/blocks/variables_test.js
+++ b/tests/mocha/blocks/variables_test.js
@@ -30,6 +30,25 @@ suite('Variables', function () {
             'variableTypes': ['', 'type1', 'type2'],
           },
         ],
+        'output': null,
+      },
+      // Block for variable setter.
+      {
+        'type': 'set_var_block',
+        'message0': '%{BKY_VARIABLES_SET}',
+        'args0': [
+          {
+            'type': 'field_variable',
+            'name': 'VAR',
+            'variableTypes': ['', 'type1', 'type2'],
+          },
+          {
+            'type': 'input_value',
+            'name': 'VALUE',
+          },
+        ],
+        'previousStatement': null,
+        'nextStatement': null,
       },
     ]);
     this.variableMap = this.workspace.getVariableMap();
@@ -59,6 +78,21 @@ suite('Variables', function () {
     return block;
   }
 
+  test('can be deleted when two connected blocks reference the same variable', function () {
+    const getter = new Blockly.Block(this.workspace, 'get_var_block');
+    getter.getField('VAR').setValue('1');
+
+    const setter = new Blockly.Block(this.workspace, 'set_var_block');
+    setter.getField('VAR').setValue('1');
+    setter.getInput('VALUE').connection.connect(getter.outputConnection);
+
+    this.variableMap.deleteVariable(this.variableMap.getVariableById('1'));
+    // Both blocks should have been deleted.
+    assert.equal(0, this.workspace.getAllBlocks(false).length);
+    // The variable itself should have been deleted.
+    assert.equal(this.variableMap.getVariableById('1'), undefined);
+  });
+
   suite('allUsedVarModels', function () {
     test('All used', function () {
       createTestVarBlock(this.workspace, '1');