QDomDocument::importNode() crashes on null nodes

QDomDocument::importNode() is unable to import null nodes. Instead of simply returning a null node, it crashes with a segmentation fault. A typical code situation where this occurs is:

QDomDocument doc1;
doc1.setContent(QByteArray("<test/>"), true);
QDomNode nullNode = doc1.elementsByTagName("doesnotexist").item(0);
QDomDocument doc2;
doc2.appendChild(doc2.importNode(nullNode, true));

Minimal code snippet to reproduce the bug:

QDomDocument doc;
doc.importNode(QDomNode(), false);