Importing a new document with 'add new version to existing history' loses first version of the document

When a document which doesn't exist is imported with the default 'add new version to existing document' is imported, the first version of the document (the one created by the import) is not accessible in the history tab. To reproduce:

• upload a .xar with a document that doesn't exist in your wiki
• import it, with the default "add new version to existing document" checked
• go to the document, open the "History" tab. A message saying: "The requested document could not be found." appears.
• modify the document, save
• view the document, go to the history tab: only one version appears, with number 2.1, marked as current. So there is no way to rollback to the original version of the document (the one that was imported).