curl-8.6.0 does not exit after retrieving web page from openssl s_server but curl-8.5.0 does #12885

gentoo-test ~ # cat > testcert.conf << EOF
[ req ]
default_bits        = 2048
default_keyfile     = testkey.pem
encrypt_key         = no
prompt              = no

distinguished_name  = cert_dn
x509_extensions     = cert_ext

[ cert_dn ]
countryName         = GB
commonName          = Common Name

[ cert_ext ]
basicConstraints    = critical, CA:FALSE
subjectAltName      = @alt_names

[ alt_names ]
DNS.1               = localhost
EOF
gentoo-test ~ # openssl req -provider default\
            -x509 -config testcert.conf -out testcert.pem
gentoo-test ~ # openssl s_server -provider default  \
                 -accept 4431 -www -key testkey.pem -cert testcert.pem &
curl --retry 5 --retry-connrefused --cacert testcert.pem https://localhost:4431/

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<pre>

s_server -provider default -accept 4431 -www -key testkey.pem -cert testcert.pem 
Secure Renegotiation IS supported
Ciphers supported in s_server binary
TLSv1.3    :TLS_AES_256_GCM_SHA384    TLSv1.3    :TLS_CHACHA20_POLY1305_SHA256 
TLSv1.3    :TLS_AES_128_GCM_SHA256    TLSv1.2    :ECDHE-ECDSA-AES256-GCM-SHA384 
TLSv1.2    :ECDHE-RSA-AES256-GCM-SHA384 TLSv1.2    :DHE-RSA-AES256-GCM-SHA384 
TLSv1.2    :ECDHE-ECDSA-CHACHA20-POLY1305 TLSv1.2    :ECDHE-RSA-CHACHA20-POLY1305 
TLSv1.2    :DHE-RSA-CHACHA20-POLY1305 TLSv1.2    :ECDHE-ECDSA-AES128-GCM-SHA256 
TLSv1.2    :ECDHE-RSA-AES128-GCM-SHA256 TLSv1.2    :DHE-RSA-AES128-GCM-SHA256 
TLSv1.2    :ECDHE-ECDSA-AES256-SHA384 TLSv1.2    :ECDHE-RSA-AES256-SHA384   
TLSv1.2    :DHE-RSA-AES256-SHA256     TLSv1.2    :ECDHE-ECDSA-AES128-SHA256 
TLSv1.2    :ECDHE-RSA-AES128-SHA256   TLSv1.2    :DHE-RSA-AES128-SHA256     
TLSv1.0    :ECDHE-ECDSA-AES256-SHA    TLSv1.0    :ECDHE-RSA-AES256-SHA      
SSLv3      :DHE-RSA-AES256-SHA        TLSv1.0    :ECDHE-ECDSA-AES128-SHA    
TLSv1.0    :ECDHE-RSA-AES128-SHA      SSLv3      :DHE-RSA-AES128-SHA        
TLSv1.2    :RSA-PSK-AES256-GCM-SHA384 TLSv1.2    :DHE-PSK-AES256-GCM-SHA384 
TLSv1.2    :RSA-PSK-CHACHA20-POLY1305 TLSv1.2    :DHE-PSK-CHACHA20-POLY1305 
TLSv1.2    :ECDHE-PSK-CHACHA20-POLY1305 TLSv1.2    :AES256-GCM-SHA384         
TLSv1.2    :PSK-AES256-GCM-SHA384     TLSv1.2    :PSK-CHACHA20-POLY1305     
TLSv1.2    :RSA-PSK-AES128-GCM-SHA256 TLSv1.2    :DHE-PSK-AES128-GCM-SHA256 
TLSv1.2    :AES128-GCM-SHA256         TLSv1.2    :PSK-AES128-GCM-SHA256     
TLSv1.2    :AES256-SHA256             TLSv1.2    :AES128-SHA256             
TLSv1.0    :ECDHE-PSK-AES256-CBC-SHA384 TLSv1.0    :ECDHE-PSK-AES256-CBC-SHA  
SSLv3      :SRP-RSA-AES-256-CBC-SHA   SSLv3      :SRP-AES-256-CBC-SHA       
TLSv1.0    :RSA-PSK-AES256-CBC-SHA384 TLSv1.0    :DHE-PSK-AES256-CBC-SHA384 
SSLv3      :RSA-PSK-AES256-CBC-SHA    SSLv3      :DHE-PSK-AES256-CBC-SHA    
SSLv3      :AES256-SHA                TLSv1.0    :PSK-AES256-CBC-SHA384     
SSLv3      :PSK-AES256-CBC-SHA        TLSv1.0    :ECDHE-PSK-AES128-CBC-SHA256 
TLSv1.0    :ECDHE-PSK-AES128-CBC-SHA  SSLv3      :SRP-RSA-AES-128-CBC-SHA   
SSLv3      :SRP-AES-128-CBC-SHA       TLSv1.0    :RSA-PSK-AES128-CBC-SHA256 
TLSv1.0    :DHE-PSK-AES128-CBC-SHA256 SSLv3      :RSA-PSK-AES128-CBC-SHA    
SSLv3      :DHE-PSK-AES128-CBC-SHA    SSLv3      :AES128-SHA                
TLSv1.0    :PSK-AES128-CBC-SHA256     SSLv3      :PSK-AES128-CBC-SHA        
---
Ciphers common between both SSL end points:
TLS_AES_256_GCM_SHA384     TLS_CHACHA20_POLY1305_SHA256 TLS_AES_128_GCM_SHA256    
ECDHE-ECDSA-AES256-GCM-SHA384 ECDHE-RSA-AES256-GCM-SHA384 DHE-RSA-AES256-GCM-SHA384 
ECDHE-ECDSA-CHACHA20-POLY1305 ECDHE-RSA-CHACHA20-POLY1305 DHE-RSA-CHACHA20-POLY1305 
ECDHE-ECDSA-AES128-GCM-SHA256 ECDHE-RSA-AES128-GCM-SHA256 DHE-RSA-AES128-GCM-SHA256 
ECDHE-ECDSA-AES256-SHA384  ECDHE-RSA-AES256-SHA384    DHE-RSA-AES256-SHA256     
ECDHE-ECDSA-AES128-SHA256  ECDHE-RSA-AES128-SHA256    DHE-RSA-AES128-SHA256     
ECDHE-ECDSA-AES256-SHA     ECDHE-RSA-AES256-SHA       DHE-RSA-AES256-SHA        
ECDHE-ECDSA-AES128-SHA     ECDHE-RSA-AES128-SHA       DHE-RSA-AES128-SHA        
AES256-GCM-SHA384          AES128-GCM-SHA256          AES256-SHA256             
AES128-SHA256              AES256-SHA                 AES128-SHA
Signature Algorithms: ECDSA+SHA256:ECDSA+SHA384:ECDSA+SHA512:Ed25519:Ed448:RSA-PSS+SHA256:RSA-PSS+SHA384:RSA-PSS+SHA512:RSA-PSS+SHA256:RSA-PSS+SHA384:RSA-PSS+SHA512:RSA+SHA256:RSA+SHA384:RSA+SHA512:ECDSA+SHA224:RSA+SHA224:DSA+SHA224:DSA+SHA256:DSA+SHA384:DSA+SHA512
Shared Signature Algorithms: ECDSA+SHA256:ECDSA+SHA384:ECDSA+SHA512:Ed25519:Ed448:RSA-PSS+SHA256:RSA-PSS+SHA384:RSA-PSS+SHA512:RSA-PSS+SHA256:RSA-PSS+SHA384:RSA-PSS+SHA512:RSA+SHA256:RSA+SHA384:RSA+SHA512:ECDSA+SHA224:RSA+SHA224
Supported groups: x25519:secp256r1:x448:secp521r1:secp384r1:ffdhe2048:ffdhe3072:ffdhe4096:ffdhe6144:ffdhe8192
Shared groups: x25519:secp256r1:x448:secp521r1:secp384r1:ffdhe2048:ffdhe3072:ffdhe4096:ffdhe6144:ffdhe8192
---
New, TLSv1.3, Cipher is TLS_AES_256_GCM_SHA384
SSL-Session:
    Protocol  : TLSv1.3
    Cipher    : TLS_AES_256_GCM_SHA384
    Session-ID: F2B0371A1A7124114427B32018A3B3AA80031580D152F82A016BAAFE7F0473D0
    Session-ID-ctx: 01000000
    Resumption PSK: 3884E08956098DDBDC76319DBC13752CBF2E172B7F0A40308BCDC09C936F8C27482E1D0CFD9B69F35F1FF63320D20D1E
    PSK identity: None
    PSK identity hint: None
    SRP username: None
    Start Time: 1707238488
    Timeout   : 7200 (sec)
    Verify return code: 0 (ok)
    Extended master secret: no
    Max Early Data: 0
---
   0 items in the session cache
   0 client connects (SSL_connect())
   0 client renegotiates (SSL_connect())
   0 client connects that finished
   1 server accepts (SSL_accept())
   0 server renegotiates (SSL_accept())
   1 server accepts that finished
   0 session cache hits
   0 session cache misses
   0 session cache timeouts
   0 callback cache hits
   0 cache full overflows (128 allowed)
---
no client certificate available
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curl 8.6.0 (x86_64-pc-linux-gnu) libcurl/8.6.0 OpenSSL/3.0.12 zlib/1.3 c-ares/1.25.0 libpsl/0.21.2 nghttp2/1.57.0 OpenLDAP/2.6.4
Release-Date: 2024-01-31
Protocols: dict file ftp ftps http https imap imaps ipfs ipns ldap ldaps mqtt pop3 pop3s rtsp smtp smtps tftp
Features: alt-svc AsynchDNS GSS-API HSTS HTTP2 HTTPS-proxy IPv6 Kerberos Largefile libz NTLM PSL SPNEGO SSL threadsafe TLS-SRP UnixSockets