importing a subset of a blog (author export) can result in a page structure without any top level page parent

[nyoungman]

When importing a subset of pages into a new blog using Wordpress XML, it can result with no pages with a page parent of 0.

As a result, the page parent setting doesn't have a drop down, and there is no option for a static page (reading), and links to pages on the public site don't work. The pages view in admin also appears flat, instead of as a hierarchy.

By simply changing the topmost page to page_parent 0 in phpMyAdmin, everything works. Ideally import would give some control over the page parents of top level page(s), or detect the situation where no page_parents of 0 exist.

[markjaquith]

Punting, as there is no patch.

[nacin]

(In [15961]) Importer and exporter overhaul, mega props duck.

Exporter overhaul:

• Add author information to export
• Greater usage of slug identifiers
• Don't export auto-drafts, spam comments, or edit lock/last meta keys
• Inline documentation improvements
• Remove filtering for now (@todo)
• Bump WXR version to 1.1, but remain back compat in the importer

Importer overhaul (​http://plugins.trac.wordpress.org/changeset/304249):

• Use an XML parser where available (SimpleXML, XML Parser)
• Proper import support for navigation menus
• Many bug fixes, specifically improvements to category and custom taxonomy handling
• Better author/user mapping

Fixes #5447 #5460 #7400 #7973 #8471 #9237 #10319 #11118 #11144 #11354 #11574 #12685 #13364 #13394 #13453 #13454 #13627 #14306 #14442 #14524 #14750 #15055 #15091 #15108.

See #15197.