"Empty Document created" event fired twice (Nuxeo FT 10.2)

Steps to reproduce:

1) Create a schema called barcode:

• barcodeID (String)

2) Create a document type a called box:

• Extends: collection
• Associated schemas: barcode

3) Create an automation chain called AC_Box_Barcode to initialize some properties of the document:

• Fetch > Context.FetchDocument
• Execution context > Context.SetVar
  • name: barcodeID
  • value: @{java.lang.String.format("%010d", java.lang.Integer.parseInt(Fn.getNextId("BoxBarCodeID") ) )}
• Document > Document.Update
  • properties: dc:title=@ {Context["barcodeID"]} bc:barcodeID=@{Context["barcodeID"]}
  • save: false

4) Create an Event handler definition:

• Events: Empty document created
• Event handler activation:
  • Current document has one of the types: box
  • Current document has facet: Any
  • Current document is: Regular Document
• Event handler execution:
  • Select an existing automation chain: AC_Box_Barcode

5) Deploy your changes

6) Create a new document 

The automation chain is called 2 times: 

• When you click on the document type icon
• When you click on the CREATE button

So, the ID is incremented in 2 units instead 1 as is expected.

NOTE: Nuxeo 10.2 used in this test

NOTE 2: To see that the event is fired twice you can replace the automation chain call for this automation script called  AS_Box_Barcode which provides the same feature but adding some logs:

function run(input, params) {
  
  Console.log("--- AS_Box_Barcode ");
  
  var id = Fn.getNextId("BarCodeId");
  
  Console.log("\t id:" + id);
  
  input = Document.Update(
    input, {
	/*required:true - type: properties*/
      'properties': "dc:title=" + id + "\nbc:barcodeID=" + id ,
	/*required:false - type: boolean*/
	'save': false
    }
  );

  return input;
}
  

This is the logs when you create a new document (onlye one). You can see the automation script has been called twice:

2019-01-16 10:09:55,742 WARN  [http-nio-0.0.0.0-8080-exec-13] [org.nuxeo.automation.scripting.helper.Console] [LOG] --- AS_Box_Barcode 
2019-01-16 10:09:55,751 WARN  [http-nio-0.0.0.0-8080-exec-13] [org.nuxeo.automation.scripting.helper.Console] [LOG] 	 id:7
2019-01-16 10:10:06,190 WARN  [http-nio-0.0.0.0-8080-exec-7] [org.nuxeo.automation.scripting.helper.Console] [LOG] --- AS_Box_Barcode 
2019-01-16 10:10:06,199 WARN  [http-nio-0.0.0.0-8080-exec-7] [org.nuxeo.automation.scripting.helper.Console] [LOG] 	 id:8
2019-01-16 10:12:14,438 INFO  [http-nio-0.0.0.0-8080-exec-15] [org.nuxeo.runtime.reload.ReloadComponent] Before updating Nuxeo server