CodeIgniter File Upload overwrite FALSE (default) auto-rename issue

[eluser]Unknown[/eluser]
Now I understood why I am getting the error message "The file name you submitted already exists on the server". The mechanism to check whether any file with the same name exists work for 100 files. It checks whether any file with the same name exists, if found, then it appends a number to filename and check again. This happens 100 times. If still a file with the same name found, it stops, so that the execution of the script will not take much time. So, we can say there is a limit and 100 is a good limit.

But I am still looking for the answer, why some files are appended an underscore, some with an underscore and then a number, and some with just the number. There is no consistency with the pattern to append a number to the files, if another file with the same name exists.