Bug in Service API "episerverapi/commerce/import/upload/commit/"

Zendesk Ticket Number/Link: https://episerver.zendesk.com/agent/tickets/422980

The problem occurs when uploading files in chunks and then performing the commit, which attempts to merge the file chunks into a single file. The file parts seem to be processed in the wrong order.

When uploading a file in chunks, temporary files are created by Episerver with the following name pattern "startByte_endByte.split".

example:
file size: 11000 bytes
chunk size: 1000 bytes

This results in 11 split files in the episerver temp folder, named as follows.
0_1000.split
1000_2000.split
2000_3000.split
3000_4000.split
4000_5000.split
5000_6000.split
6000_7000.split
7000_8000.split
8000_9000.split
9000_10000.split
10000_11000.split

When performing the commit operation, Episerver processes them in the filename-order, resulting in a corrupted file after the merge.

The process order for this example would be (the items in red causing corrupted result):
0_1000.split
10000_11000.split
1000_2000.split
2000_3000.split
3000_4000.split
4000_5000.split
5000_6000.split
6000_7000.split
7000_8000.split
8000_9000.split
9000_10000.split