Add a parameter not to save the document in the operation 'Document.SetMetadataFromBlob'

Currently, when operation Document.SetMetadataFromBlob is called in an automation script triggered by a Before document modification event handler, it calls CoreSession.saveDocument(DocumentModel (see here), which causes recursive calls.

Saving the document must be an option (e.g. using a save parameter), like it is done in several operations that update the document's properties (e.g. Document.SetProperty).

How to reproduce:

• in Studio, define the following metadata mapping in a XML extension:

  <extension point="metadataMappings" target="org.nuxeo.binary.metadata">
    
    <metadataMapping id="exif" processor="exifTool" blobXPath="file:content" ignorePrefix="false" >
      <metadata name="File:MIMEType" xpath="dc:description" />
    </metadataMapping>
    
  </extension>
  

• define an event handler, triggered by event Before document modification for documents of type Picture, running the following automation script:

  function run(input, params) {
      var mimeType = input['file:content/mime-type'];
      if(mimeType.startsWith('image/')) {
        Document.SetMetadataFromBlob(input, { 'metadataMappingId': 'exif' } );
      }    
    }
    return input;
  }
  

• deploy
• log in the Web UI
• create a Picture document without an attached blob
• attach an image containing the metadata mentioned in the metadata mapping above

Expected result: the metadata is extracted from the image file and the document property is set with its value
Actual result: the metadata is extracted from the image file but the document property is not set. If the automation tracing is activated, a lot of logs should be generated in the server.log file, showing recursive calls