We have a CI job to spot unwanted utf8 letters in #curl PRs as we have noticed that GitHub will gladly show the for example (identical) Cyrillic version of a letter next to the Latin version in a diff and it is yes, entirely impossible for a human to spot the diff. I mean the diff is shown, but the significance of it is not.

Changing just a single letter like that in a URL hostname opens up for a world of grief.

@bagder Can you share this job? I'm really interested in how it's built.
@kaiserkiwi the job is not cleanly only doing this but is done as part of a bunch of other scanning duties by this script: https://github.com/curl/curl/blob/master/.github/scripts/spacecheck.pl
curl/.github/scripts/spacecheck.pl at master · curl/curl

A command line tool and library for transferring data with URL syntax, supporting DICT, FILE, FTP, FTPS, GOPHER, GOPHERS, HTTP, HTTPS, IMAP, IMAPS, LDAP, LDAPS, MQTT, POP3, POP3S, RTMP, RTMPS, RTSP...

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