merging signed pdf files

[gregkotsaftis]

When merging a digitally signed pdf file e.g. a legal document signed by a government authority and a simple bank receipt e.g. for paying for that government document, the digitally sign is being removed. This is of course the proper thing to do and I understand this!
But it would be nice to notify the user before merging that a document is digitally signed and that sign will be lost after merging!
Keeping one merged pdf instead of two e.g. an invoice and a receipt for that invoice, is extremely helpful for me but for digitally signed pdfs, it is better to warn the user before merging and possibly deleting the original files (as i do...) cause he will assume he does not need them anymore!