head: negative numbers broken

[E5ten]

head -n -1 with no file argument results in head: error: Argument to option 'n' missing, and with a file argument (e.g. head -n -1 file) results in head: error: invalid line count 'file': invalid digit found in string. head should detect that the -1 isn't an option despite the dash before it, but a negative argument to -n and correctly print all the lines in the file it is used on except the last.

[Arcterus]

Is -c also an issue?

[E5ten]

Yes

[sylvestre]

Fixed by #1510