Special characters in ftpdrop

I uploaded a few test files with some characters that have given me issues in the past with other systems with an ftpdrop.

The file names were:
colon:a.txt
em—dash.txt
emoji☺.txt
en–dash.txt
reg-dash.txt
testfile.txt

The only files that were delivered to the recipient were. testfile.txt, colon:a.txt, and reg-dash.txt

Sample errors in the syslog:

27 Feb, 2024 11:24:51 ftpdrop err Backtrace (rescued error):#012/usr/lib/ruby/3.0.0/fileutils.rb:551:in `rename'#012/usr/lib/ruby/3.0.0/fileutils.rb:551:in `block in mv'#012/usr/lib/ruby/3.0.0/fileutils.rb:1597:in `block in fu_each_src_dest'#012/usr/lib/ruby/3.0.0/fileutils.rb:1613:in `fu_each_src_dest0'#012/usr/lib/ruby/3.0.0/fileutils.rb:1595:in `fu_each_src_dest'#012/usr/lib/ruby/3.0.0/fileutils.rb:542:in `mv'#012/app/current/bin/ftpdrop:71:in `block in <main>'#012/app/current/bin/ftpdrop:19:in `each_line'#012/app/current/bin/ftpdrop:19:in `each_line'#012/app/current/bin/ftpdrop:19:in `<main>'
27 Feb, 2024 11:24:51 ftpdrop err ERROR: No such file or directory @ rb_file_s_rename - (/data/ftpdrop/ftp-test/en\–dash.txt, /data/ftpdrop/ftp-test/en_dash.txt)