This issue was noticed in Acrobat 9 and 10. When deleting a page from a large document (200+ pages) Acrobat throws an error (a non descriptive error...). The problem is due to the way FOP generates /PageLabels, which although correct is not according to the spirit of the spec. The patch addresses the issue by generating the /PageLabels dictionary in a more Acrobat friendly way.
Created attachment 29493 [details] patch
applied: http://svn.apache.org/viewvc?view=revision&revision=1399483
Well done Luis, but how did you find out that the problem was the /PageLabels given the Acrobat's non descriptive error ?
Created attachment 29495 [details] example source and output Even though Acrobat was throwing an error it was nevertheless deleting the page. But I noticed that the thumbnail page images (in the left pane) were not being deleted. Since the labels of the thumbnails come from /PageLabels I decided to disable /PageLabels (by renaming it to, say, /PageLabelz) and see what would happen. The Acrobat error disappeared! Attached is an example *.fo source and the PDF output after and before the fix for those with Acrobat.
Thanks for the explanations and the example, it was a good catch.