Import fails on document archive field

We get the following exception on an import of a very large xar with version history:

org.apache.commons.codec.DecoderException: Invalid URL encoding
at org.apache.commons.codec.net.URLCodec.decodeUrl(URLCodec.java:170)
at com.xpn.xwiki.doc.rcs.XWikiRCSArchive$XWikiJRCSNode.getAuthor1(XWikiRCSArchive.java:173)
at com.xpn.xwiki.doc.rcs.XWikiRCSArchive.getNodes(XWikiRCSArchive.java:234)
at com.xpn.xwiki.doc.XWikiDocumentArchive.setArchive(XWikiDocumentArchive.java:216)
at com.xpn.xwiki.doc.XWikiDocument.setDocumentArchive(XWikiDocument.java:887)
at com.xpn.xwiki.doc.XWikiDocument.fromXML(XWikiDocument.java:2397)
at com.xpn.xwiki.doc.XWikiDocument.fromXML(XWikiDocument.java:2361)
at com.xpn.xwiki.plugin.packaging.Package.readFromXML(Package.java:715)
at com.xpn.xwiki.plugin.packaging.Package.Import(Package.java:388)
at com.xpn.xwiki.plugin.packaging.PackageAPI.Import(PackageAPI.java:173)
at com.xpn.xwiki.web.ImportAction.render(ImportAction.java:42)