Problem: tcp address strings are dependent on locale

Solution: use sprintf instead of std::stringstream
Fixes zeromq#3385

src/tcp_address.cpp

@@ -29,7 +29,6 @@
 
 #include "precompiled.hpp"
 #include <string>
-#include <sstream>
 
 #include "macros.hpp"
 #include "tcp_address.hpp"
@@ -113,6 +112,27 @@ int zmq::tcp_address_t::resolve (const char *name_, bool local_, bool ipv6_)
  return resolver.resolve (&_address, name_);
 }
 
+template <size_t N1, size_t N2>
+static std::string make_address_string (const char *hbuf,
+ in_port_t port,
+ const char (&ipv6_prefix)[N1],
+ const char (&ipv6_suffix)[N2])
+{
+ const size_t max_port_str_length = 5;
+ char buf[NI_MAXHOST + sizeof ipv6_prefix + sizeof ipv6_suffix
+ + max_port_str_length];
+ char *pos = buf;
+ memcpy (pos, ipv6_prefix, sizeof ipv6_prefix - 1);
+ pos += sizeof ipv6_prefix - 1;
+ const int hbuf_len = strlen (hbuf);
+ memcpy (pos, hbuf, hbuf_len);
+ pos += hbuf_len;
+ memcpy (pos, ipv6_suffix, sizeof ipv6_suffix - 1);
+ pos += sizeof ipv6_suffix - 1;
+ pos += sprintf (pos, "%d", ntohs (port));
+ return std::string (buf, pos - buf);
+}
+
 int zmq::tcp_address_t::to_string (std::string &addr_) const
 {
  if (_address.family () != AF_INET && _address.family () != AF_INET6) {
@@ -130,14 +150,16 @@ int zmq::tcp_address_t::to_string (std::string &addr_) const
  return rc;
  }
 
+ const char ipv4_prefix[] = "tcp://";
+ const char ipv4_suffix[] = ":";
+ const char ipv6_prefix[] = "tcp://[";
+ const char ipv6_suffix[] = "]:";
  if (_address.family () == AF_INET6) {
- std::stringstream s;
- s << "tcp://[" << hbuf << "]:" << ntohs (_address.ipv6.sin6_port);
- addr_ = s.str ();
+ addr_ = make_address_string (hbuf, _address.ipv6.sin6_port, ipv6_prefix,
+ ipv6_suffix);
  } else {
- std::stringstream s;
- s << "tcp://" << hbuf << ":" << ntohs (_address.ipv4.sin_port);
- addr_ = s.str ();
+ addr_ = make_address_string (hbuf, _address.ipv4.sin_port, ipv4_prefix,
+ ipv4_suffix);
  }
  return 0;
 }
@@ -263,15 +285,29 @@ int zmq::tcp_address_mask_t::to_string (std::string &addr_) const
  return rc;
  }
 
+ const size_t max_mask_len = 4;
+ const char ipv6_prefix[] = "[";
+ const char ipv6_suffix[] = "]/";
+ const char ipv4_suffix[] = "/";
+ char
+ buf[NI_MAXHOST + sizeof ipv6_prefix + sizeof ipv6_suffix + max_mask_len];
+ char *pos = buf;
+ if (_network_address.family () == AF_INET6) {
+ memcpy (pos, ipv6_prefix, sizeof ipv6_prefix - 1);
+ pos += sizeof ipv6_prefix - 1;
+ }
+ const int hbuf_len = strlen (hbuf);
+ memcpy (pos, hbuf, hbuf_len);
+ pos += hbuf_len;
  if (_network_address.family () == AF_INET6) {
- std::stringstream s;
- s << "[" << hbuf << "]/" << _address_mask;
- addr_ = s.str ();
+ memcpy (pos, ipv6_suffix, sizeof ipv6_suffix - 1);
+ pos += sizeof ipv6_suffix - 1;
  } else {
- std::stringstream s;
- s << hbuf << "/" << _address_mask;
- addr_ = s.str ();
+ memcpy (pos, ipv4_suffix, sizeof ipv4_suffix - 1);
+ pos += sizeof ipv4_suffix - 1;
  }
+ pos += sprintf (pos, "%d", _address_mask);
+ addr_.assign (buf, pos - buf);
  return 0;
 }