Moving page tree to a new space breaks some links within the tree

When a tree of pages with links between them is moved from one space to another, some of the links are updated but others are left pointing to the original space. I expect it depends on the order in which the pages are moved.

To reproduce:

• create a page A in space 1
• create two child pages A1 and A2 below A
• create a link from A1 to A2 and from A2 to A1
• move page A to space 2
• look at A1 and A2 in space 2 - one of the links will be fine, the other will be broken because it's looking for the page in space 1

This can result in a lot of work required to fix up broken links after moving a tree of pages.