test-sysrepo_system-ietfinterfaces fails with libyang error "Node already exists" about velia

[peckato1]

I managed to reproduce this issue.

The values map (containing the data to be processed by libyang & sysrepo) is sorted lexicographically on strings. However, there is a list in the mapping (/ietf-routing:routing/ribs/rib/routes/route) with indexes that are greater or equal to 10 and path /path/to/list[10] is lexicographically smaller than /path/to/list[1]. Therefore this list index gets processed first by libyang and the subsequent processing of index 1 breaks everything.

Reproducer:

#include <libyang/Libyang.hpp>
#include <libyang/Tree_Data.hpp>
#include <libyang/Tree_Data.hpp>
#include <map>
#include <sysrepo-cpp/Session.hpp>

void valuesToYang(const std::map<std::string, std::string>& values, std::shared_ptr<::sysrepo::Session> session, std::shared_ptr<libyang::Data_Node>& parent)

{
    for (const auto& [propertyName, value] : values) {
        std::cout << "Processing node update " << propertyName << " -> " << value << std::endl;

        if (!parent) {
            parent = std::make_shared<libyang::Data_Node>(
                session->get_context(),
                propertyName.c_str(),
                value.c_str(),
                LYD_ANYDATA_CONSTSTRING,
                LYD_PATH_OPT_OUTPUT);
        } else {
            parent->new_path(
                session->get_context(),
                propertyName.c_str(),
                value.c_str(),
                LYD_ANYDATA_CONSTSTRING,
                LYD_PATH_OPT_OUTPUT);
        }
    }
}

int main()
{
	auto srConn = std::make_shared<sysrepo::Connection>();
	auto srSess = std::make_shared<sysrepo::Session>(srConn);

	std::map<std::string, std::string> values;

	for(int i = 1; i <= 10; i++) {
		const auto yangPrefix = "/ietf-routing:routing/ribs/rib[name='ipv4-master']/routes/route[" + std::to_string(i) + "]/ietf-ipv4-unicast-routing";
		values[yangPrefix + ":destination-prefix"] = "0.0.0.0/0";
	}

	libyang::S_Data_Node parent;
	valuesToYang(values, srSess, parent);

	return 0;
}