Leaving page title blank when using Doc Import can break all internal hyperlinks in the space

If you use the Advanced options when importing via the Doc Import feature, it's possible to leave the page title blank. (See CONF-17414). If you subsequently rename the resulting unnamed page, the new page name is prepended to all existing internal links on every page throughout the space.

For example, changing the unnamed page to "Page 123" does this to all your links:

[Hello World|#helloworld]
is changed to
[Hello World|Page 123#helloworld]

[^myspreadsheet.xls]
is changed to
[Page 123^myspreadsheet.xls]

[My Word Document|^my_word_document.doc]
is changed to
[My Word Document|Page 123^my_word_document.doc]

The changes show up in the history for every affected page just as if you'd edited them manually. Deleting the rogue page has no effect. The only fix is to revert the pages one at a time.