Only create a new revision when necessary

Closes #3493179

src/Plugin/Field/FieldType/EntityReferenceRevisionsItem.php

@@ -279,8 +279,19 @@ class EntityReferenceRevisionsItem extends EntityReferenceItem implements Option
       $is_affected = !$this->getFieldDefinition()->isTranslatable() || ($host instanceof TranslatableRevisionableInterface && $host->hasTranslationChanges());
       if ($is_affected && !$host->isNew() && $this->entity && $this->entity->getEntityType()->get('entity_revision_parent_id_field')) {
         if ($host->isNewRevision()) {
-          $this->entity->setNewRevision();
-          $needs_save = TRUE;
+          $has_newer_revision = FALSE;
+          if (!empty($host->original)) {
+            $old_revision_id = $host->original->get($this->getFieldDefinition()->getName())->get($this->getName())->target_revision_id;
+            if ($old_revision_id < $this->target_revision_id) {
+              // If the item is pointing to a newer revision we should not
+              // be creating one.
+              $has_newer_revision = TRUE;
+            }
+          }
+          if (!$has_newer_revision) {
+            $this->entity->setNewRevision();
+            $needs_save = TRUE;
+          }
         }
         // Additionally ensure that the default revision state is kept in sync.
         if ($this->entity && $host->isDefaultRevision() != $this->entity->isDefaultRevision()) {