Export fails with checkNotNull exception - need to allow pages with null ID

[GoogleCodeExporter]

I have tried exporting my site from three different computers, and it 
never completes.

The Progress window shows the page that the export stops on. The cmd 
window shows the warnings and error below.
I deleted the page that the export was initially stopping on according to 
the progress window. But now the export stops on a different page, but 
with the same error in the cmd window.

It seems that the export process has an expectation about "non-null id" 
values that Sites does not enforce.

cmd window warnings and error:
WARNING: All entries should have a unique non-null id!
Feb 23, 2010 9:03:03 PM 
com.google.sites.liberation.export.InMemoryEntryStore ad
dEntry
WARNING: All entries should have a unique non-null id!
Feb 23, 2010 9:03:03 PM 
com.google.sites.liberation.export.InMemoryEntryStore ad
dEntry
WARNING: All entries should have a unique non-null id!
Exception in thread "Thread-4" java.lang.NullPointerException: text
        at com.google.common.base.Preconditions.checkNotNull
(Preconditions.java:
203)
        at com.google.sites.liberation.renderers.RendererUtils.getHyperLink
(Rend
ererUtils.java:140)
        at 
com.google.sites.liberation.renderers.RendererUtils.getAuthorElement(
RendererUtils.java:71)
        at 
com.google.sites.liberation.renderers.ContentRendererImpl.renderConte
nt(ContentRendererImpl.java:39)
        at com.google.sites.liberation.export.PageExporterImpl.exportPage
(PageEx
porterImpl.java:123)
        at com.google.sites.liberation.export.SiteExporterImpl.exportPage
(SiteEx
porterImpl.java:158)
        at com.google.sites.liberation.export.SiteExporterImpl.exportSite
(SiteEx
porterImpl.java:131)
        at 
com.google.sites.liberation.util.GuiMain$ImportExportRunnable.run(Gui
Main.java:279)
        at java.lang.Thread.run(Unknown Source)

Original issue reported on code.google.com by [email protected] on 24 Feb 2010 at 2:25

[GoogleCodeExporter]

this problem is the same as reported on issue 32.

Original comment by [email protected] on 29 Apr 2010 at 9:51