NetBSD gethostbyname_r is not compatible with Tcl usage

Index: unix/configure.in
==================================================================
--- unix/configure.in
+++ unix/configure.in
@@ -253,10 +253,15 @@
 	AC_DEFINE(HAVE_MTSAFE_GETHOSTBYNAME, 1,
 		[Do we have MT-safe gethostbyname() ?])
 	AC_DEFINE(HAVE_MTSAFE_GETHOSTBYADDR, 1,
 		[Do we have MT-safe gethostbyaddr() ?])
 
+    elif test "`uname -s`" = "NetBSD"; then
+	# Do nothing. NetBSD's gethostbyname_r is not compatible
+	# with our usage, and is not clear from the documentation
+	# whether gethostbyname is MT-safe or not, so better play safe.
+
     else
 	SC_TCL_GETHOSTBYNAME_R
 	SC_TCL_GETHOSTBYADDR_R
     fi
 fi

