title: Solr-Atomic Update changes other fields
body: <p>While running on atomic update,language field is getting changed.We have flow as below.</p>
  
  <p>During indexing object posted is
  {
  id:"234-567",
  fileName:"file1",
  content:""
  }</p>
  
  <p>In the pipeline we analyse content as part of language detection and create a new field "language" which is working as expected.</p>
  
  <p>But while doing atomic update 
  {
  id:"as above"
  fileName:"changed"
  }</p>
  
  <p>to change fileName,we make use to "set" operation which is updating field correctly but <strong>language</strong> field is getting changed to fallback value.</p>
  
  <p>What is happening here?Is it looking for content field to analysis again?Does atomic update also goes through processing pipeline</p>