SSL_OPTIONS: set SSL options on Curl library (#3936)

CMakeLists.txt

@@ -228,6 +228,13 @@ if(ENABLE_CURL)
         INTERFACE_LINK_LIBRARIES      "${CURL_LIBRARIES}"
       )
     endif()
+
+    # Curl SSL options are described in
+    #   https://curl.se/libcurl/c/CURLOPT_SSL_OPTIONS.html
+    #set(CURLSSLOPT_NO_REVOKE 2)
+    #set(SSL_OPTIONS ${CURLSSLOPT_NO_REVOKE})
+    #add_compile_definitions(SSL_OPTIONS=${SSL_OPTIONS})
+
   else()
     message(SEND_ERROR "curl dependency not found!")
   endif()

src/networkfilemanager.cpp

@@ -1620,6 +1620,13 @@ CurlFileHandle::CurlFileHandle(PJ_CONTEXT *ctx, const char *url, CURL *handle)
         CHECK_RET(ctx, curl_easy_setopt(handle, CURLOPT_SSL_VERIFYHOST, 0L));
     }
 
+#if defined(SSL_OPTIONS)
+    // https://curl.se/libcurl/c/CURLOPT_SSL_OPTIONS.html
+    auto ssl_options = static_cast<long>(SSL_OPTIONS);
+    CHECK_RET(ctx,
+              curl_easy_setopt(handle, CURLOPT_SSL_OPTIONS, ssl_options));
+#endif
+
     const auto ca_bundle_path = pj_context_get_bundle_path(ctx);
     if (!ca_bundle_path.empty()) {
         CHECK_RET(ctx, curl_easy_setopt(handle, CURLOPT_CAINFO,