curl --upload-file "{file1,file2}" loops forever

[kdudka]

The following command:

$ touch file1 && curl -T '{file1,file2}' sftp://localhost/tmp/ -u :

... lops forever with curl-7.67.0:

  % Total    % Received % Xferd  Average Speed   Time    Time     Time  Current
                                 Dload  Upload   Total   Spent    Left  Speed
  0     0    0     0    0     0      0      0 --:--:-- --:--:-- --:--:--     0
  0     0    0     0    0     0      0      0 --:--:-- --:--:-- --:--:--     0
curl: (3) URL using bad/illegal format or missing URL
curl: (3) URL using bad/illegal format or missing URL
curl: (3) URL using bad/illegal format or missing URL
curl: (3) URL using bad/illegal format or missing URL
curl: (3) URL using bad/illegal format or missing URL
curl: (3) URL using bad/illegal format or missing URL
curl: (3) URL using bad/illegal format or missing URL
curl: (3) URL using bad/illegal format or missing URL
[...]

It seems to be caused by commit e59371a (PR #4438).

Originally reported at: https://bugzilla.redhat.com/1771025

[bagder]

Ouch. I'm on it.

[bagder]

Turns out we don't have a single test using this feature! 😞

[klingtnet]

Can confirm this issue for curl 7.67.0 on Arch Linux.

Minimal working example:

$ curl --upload-file '{A,B}' httpbin.org/post

where A and B are some random files.

$ curl --version
curl 7.67.0 (x86_64-pc-linux-gnu) libcurl/7.67.0 OpenSSL/1.1.1d zlib/1.2.11 libidn2/2.2.0 libpsl/0.21.0 (+libidn2/2.2.0) libssh2/1.9.0 nghttp2/1.39.2
Release-Date: 2019-11-06
Protocols: dict file ftp ftps gopher http https imap imaps pop3 pop3s rtsp scp sftp smb smbs smtp smtps telnet tftp 
Features: AsynchDNS GSS-API HTTP2 HTTPS-proxy IDN IPv6 Kerberos Largefile libz NTLM NTLM_WB PSL SPNEGO SSL TLS-SRP UnixSockets

[bagder]

Sure, this bug is in 7.67.0 for all builds and distros.