A value like 'cloudflare-dns.com/dns-query' is the sing-box DoH
path format. The previous check only caught 'https://' URLs.
dns_server_value_valid() accepts it because it validates only the
host part — so 'cloudflare-dns.com' passed as a valid hostname.
Fallback servers are plain UDP only; any '/' in the value is the
DoH path separator and must be rejected.
Changes:
- validator.uc: add index(value, '/') >= 0 check before the
dns_server_value_valid call
- config_validator_runtime.sh: add regression test for path-style
DoH ('cloudflare-dns.com/dns-query') in dns_fallback_server
Dushnilin
6b8e143d0b