fix issue on alphanumeric sorting on filenames

Signed-off-by: mrtrkmn [email protected]

When I use the pdfcpu tool I have realized an issue regarding to sorting files when we want to merge.

The problem occurs when we have filenames which are like

• a-2-b
• a-32-b
• a-12-a
• a-4-b

Small example to the problem can be found here:

https://play.golang.com/p/3FuTcjOpU3j

Expected result: [a-2-b a-4-b a-12-a a-32-b]

Actual result: [a-12-a a-2-b a-32-b a-4-b]

All committers have signed the CLA.

There is a bug that on this feature request, therefore, converted into draft.

Hi there and sorry for the delay!

Your suggested file sorting extension prior to merging maskes sense unfortunately this is not something I can accept right away and here is why:

This is a CLI extension and we need to be careful to remain backwards compatible. There is aleady a sort flag on the merge command and this needs to be extended. Rest assured I will consider this and include it in the next release.

Thank you for your contribution 💚

For backwards compatibility reasons I have decided the sort option on the CLI remains as is. Any sophisticated sorting can easily be injected when using the API.