diff --git a/source b/source index f42733c9bb6..015ab1b24d8 100644 --- a/source +++ b/source @@ -64358,17 +64358,20 @@ o............A....e insertedNode, are:

    -
  1. -

    If insertedNode is not connected, then return.

    +

  2. If insertedNode is parser-inserted, then return.

    3. -
    -

    This can happen in the case where an earlier-inserted script removes a - later-inserted script. For instance:

    +

  3. Prepare the script element given insertedNode.

    4. +
- 
<script>
+  

+   
The HTML element post-connection steps only run when the inserted element is
+   still connected, which protects against cases where an earlier-inserted
+   script removes a later-inserted script. For instance:

+
+   
<script>
 const script1 = document.createElement('script');
 script1.innerText = `
-  document.querySelector('#script2').remove();
+document.querySelector('#script2').remove();
 `;
 
 const script2 = document.createElement('script');
@@ -64378,24 +64381,20 @@ script2.textContent = `console.log('script#2 running')`;
 document.body.append(script1, script2);
 </script>

 
-     
Nothing is printed to the console in this example. By the time the HTML element
-     post-connection steps run for the first script that was atomically inserted
-     by append(), it can observe that the second
-     script is already connected to the DOM. It removes the second
-     script, so that by the time its HTML element post-connection
-     steps run, it is no longer connected, and does not get prepared.

-    

-   
-
-   
  • If insertedNode is parser-inserted, then return.
    • 
-
-   
  • Prepare the script element given insertedNode.
    • 
-  
+   
    Nothing is printed to the console in this example. By the time the HTML element
+   post-connection steps run for the first script that was atomically inserted
+   by append(), it can observe that the second
+   script is already connected to the DOM, and it removes it from the DOM.
+   Because the second script is no longer connected, its HTML
+   element post-connection steps do not run, and it does not get prepared.
    
+  
 
   
    The script children changed steps are:
    
 
   
      
+   
    1. If the script element is not connected, then return.
      2. 
+
    
    2. Run the script HTML element post-connection steps, given the
    script element.
      3. 
   
    
@@ -64449,9 +64448,9 @@ document.body.append(script1, script2);
   
      
    
    1. If namespace is not null, then return.
      2. 
 
-   
    2. If localName is src, then run the
-   script HTML element post-connection steps, given
-   element.
      3. 
+   
    3. If localName is src and
+   element is connected, then run the script HTML element
+   post-connection steps, given element.
      4. 
   
    
 
   
    To prepare the script element given a script