[PATCH COMMITTED] support_format_addrinfo: Include unknown error number in result

[Florian Weimer]

2018-04-01  Florian Weimer  <fweimer@redhat.com>

	* support/support_format_addrinfo.c (support_format_addrinfo):
	Include unknown error number in formatted result.

diff --git a/support/support_format_addrinfo.c b/support/support_format_addrinfo.c
index c5e00e516a..f9dc97c24d 100644
--- a/support/support_format_addrinfo.c
+++ b/support/support_format_addrinfo.c
@@ -220,7 +220,11 @@ support_format_addrinfo (struct addrinfo *ai, int ret)
   xopen_memstream (&mem);
   if (ret != 0)
     {
-      fprintf (mem.out, "error: %s\n", gai_strerror (ret));
+      const char *errmsg = gai_strerror (ret);
+      if (strcmp (errmsg, "Unknown error") == 0)
+        fprintf (mem.out, "error: Unknown error %d\n", ret);
+      else
+        fprintf (mem.out, "error: %s\n", errmsg);
       if (ret == EAI_SYSTEM)
         {
           errno = errno_copy;