Make libcurl respect the SSL_CERT_{DIR,FILE} variables by default. The variables
are fetched during initialization to preserve thread-safety (curl_global_init(3)
must be called when no other threads exist).

This fixes network functionality in rust:cargo, and probably removes the need
for other future workarounds.
===================================================================
--- curl-7.66.0.orig/lib/easy.c	2020-01-02 15:43:11.883921171 +0100
+++ curl-7.66.0/lib/easy.c	2020-01-02 16:18:54.691882797 +0100
@@ -134,6 +134,9 @@
 #  pragma warning(default:4232) /* MSVC extension, dllimport identity */
 #endif
 
+char * Curl_ssl_cert_dir = NULL;
+char * Curl_ssl_cert_file = NULL;
+
 /**
  * curl_global_init() globally initializes curl given a bitwise set of the
  * different features of what to initialize.
@@ -155,6 +158,9 @@
 #endif
   }
 
+  Curl_ssl_cert_dir = curl_getenv("SSL_CERT_DIR");
+  Curl_ssl_cert_file = curl_getenv("SSL_CERT_FILE");
+
   if(!Curl_ssl_init()) {
     DEBUGF(fprintf(stderr, "Error: Curl_ssl_init failed\n"));
     return CURLE_FAILED_INIT;
@@ -260,6 +266,9 @@
   Curl_ssl_cleanup();
   Curl_resolver_global_cleanup();
 
+  free(Curl_ssl_cert_dir);
+  free(Curl_ssl_cert_file);
+
 #ifdef WIN32
   Curl_win32_cleanup(init_flags);
 #endif
diff -ur curl-7.66.0.orig/lib/url.c curl-7.66.0/lib/url.c
--- curl-7.66.0.orig/lib/url.c	2020-01-02 15:43:11.883921171 +0100
+++ curl-7.66.0/lib/url.c	2020-01-02 16:21:11.563880346 +0100
@@ -524,6 +524,21 @@
     if(result)
       return result;
 #endif
+    extern char * Curl_ssl_cert_dir;
+    extern char * Curl_ssl_cert_file;
+    if(Curl_ssl_cert_dir) {
+        if(result = Curl_setstropt(&set->str[STRING_SSL_CAPATH], Curl_ssl_cert_dir))
+            return result;
+        if(result = Curl_setstropt(&set->str[STRING_SSL_CAPATH_PROXY], Curl_ssl_cert_dir))
+            return result;
+    }
+
+    if(Curl_ssl_cert_file) {
+        if(result = Curl_setstropt(&set->str[STRING_SSL_CAFILE], Curl_ssl_cert_file))
+            return result;
+        if(result = Curl_setstropt(&set->str[STRING_SSL_CAFILE_PROXY], Curl_ssl_cert_file))
+            return result;
+    }
   }
 
   set->wildcard_enabled = FALSE;
x/log/gnu/services?id=7d60b97a6f3997600d6b95901c2c223dea24b3d6'>services</a>/<a href='/guix/log/gnu/services/hurd.scm?id=7d60b97a6f3997600d6b95901c2c223dea24b3d6'>hurd.scm</a></div><div class='content'><table class='list nowrap'><tr class='nohover'><th class='left'>Age</th><th class='left'>Commit message (<a href='/guix/log/gnu/services/hurd.scm?id=7d60b97a6f3997600d6b95901c2c223dea24b3d6&amp;showmsg=1'>Expand</a>)</th><th class='left'>Author</th></tr>
<tr><td><span title='2021-11-30 01:08:55 +0100'>2021-11-30</span></td><td><a href='/guix/commit/gnu/services/hurd.scm?id=892f1b7273d57b25940700877a02618fe826cc08'>services: Accept &lt;inferior-package&gt;s in lieu of &lt;package&gt;s.</a><span class='msg-avail'>...<span class='msg-tooltip'>* gnu/services/authentication.scm (fprintd-configuration)
(nslcd-configuration): Substitute file-like objects for package ones.
* gnu/services/cgit.scm (cgit-configuration, opaque-cgit-configuration):
Likewise.
* gnu/services/cups.scm (package-list?, cups-configuration): Likewise.
* gnu/services/dns.scm (verify-knot-configuration)
(ddclient-configuration): Likewise.
* gnu/services/docker.scm (docker-configuration): Likewise.
* gnu/services/file-sharing.scm (transmission-daemon-configuration): Likewise.
* gnu/services/getmail.scm (getmail-configuration): Likewise.
* gnu/services/mail.scm (dovecot-configuration)
(opaque-dovecot-configuration): Likewise.
* gnu/services/messaging.scm (prosody-configuration)
(opaque-prosody-configuration): Likewise.
* gnu/services/monitoring.scm (zabbix-server-configuration)
(zabbix-agent-configuration): Likewise.
* gnu/services/networking.scm (opendht-configuration): Likewise.
* gnu/services/pm.scm (tlp-configuration): Likewise.
* gnu/services/telephony.scm (jami-configuration): Likewise.
* gnu/services/virtualization.scm (libvirt-configuration)
(qemu-guest-agent-configuration): Likewise.
* gnu/services/vpn.scm (openvpn-client-configuration): Likewise.
</span></span></td><td>Tobias Geerinckx-Rice</td></tr>