From cdec4dc9ee51458f991ad6778ae3244accef621a Mon Sep 17 00:00:00 2001
From: Min RK <benjaminrk@gmail.com>
Date: Sat, 30 Jan 2016 21:29:20 +0100
Subject: [PATCH] allow underscores in domain names

Since they are allowed

(They are not, however, allowed in hostnames)
---
 src/socket_base.cpp | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/src/socket_base.cpp b/src/socket_base.cpp
index 1dbcab61..7db767e8 100644
--- a/src/socket_base.cpp
+++ b/src/socket_base.cpp
@@ -845,8 +845,10 @@ int zmq::socket_base_t::connect (const char *addr_)
             while (isalnum  (*check)
                 || isxdigit (*check)
                 || *check == '.' || *check == '-' || *check == ':' || *check == '%'
-                || *check == ';' || *check == ']')
+                || *check == ';' || *check == ']' || *check == '_'
+            ) {
                 check++;
+            }
         }
         //  Assume the worst, now look for success
         rc = -1;