`curl -JO` appends data to an existing output file

[kdudka]

I did this

curl -JO --location https://github.com/curl/curl/releases/download/curl-7_63_0/curl-7.63.0.tar.xz.asc
curl -JO --location https://github.com/curl/curl/releases/download/curl-7_63_0/curl-7.63.0.tar.xz.asc

I expected the following

I expected curl-7.63.0.tar.xz.asc to be written only once. However, it was written twice and concatenated together. Note that it is not needed to use --location to trigger the bug. It looks like the fix in #2813 was incomplete. Originally reported at https://bugzilla.redhat.com/1658574

curl/libcurl version

curl-7_63_0-13-g9e6518481

[curl -V output]

curl 7.63.0-DEV (x86_64-pc-linux-gnu) libcurl/7.63.0-DEV OpenSSL/1.1.1 zlib/1.2.11 brotli/1.0.7 libidn2/2.0.5 libpsl/0.20.2 (+libidn2/2.0.5) nghttp2/1.35.1
Release-Date: [unreleased]
Protocols: dict file ftp ftps gopher http https imap imaps ldap ldaps pop3 pop3s rtsp smb smbs smtp smtps telnet tftp 
Features: AsynchDNS IDN IPv6 Largefile GSS-API Kerberos SPNEGO NTLM NTLM_WB SSL libz brotli TLS-SRP HTTP2 UnixSockets HTTPS-proxy PSL 

operating system

Linux

[bagder]

grrr, typo closed the wrong issue!