[PATCH 3/6] nss: Use test resolver for bug-erange

Rewrite the gethostbyname_r ERANGE test to use the resolv_test
framework instead of querying the network, so it can run as a regular
test.
---
 nss/Makefile     |  7 ++--
 nss/bug-erange.c | 90 +++++++++++++++++++++++++++++-------------------
 2 files changed, 57 insertions(+), 40 deletions(-)

diff --git a/nss/Makefile b/nss/Makefile
index bbcb7201699..4cab4f74c42 100644
--- a/nss/Makefile
+++ b/nss/Makefile
@@ -312,6 +312,7 @@ tests-internal := \
   # tests-internal
 
 tests := \
+  bug-erange \
   bug17079 \
   test-digits-dots \
   test-netdb \
@@ -343,10 +344,6 @@ tests := \
   tst-shadow \
   # tests
 
-xtests := \
-  bug-erange \
-  # xtests
-
 tests-container := \
   tst-initgroups1 \
   tst-initgroups2 \
@@ -517,6 +514,8 @@ $(objpfx)tst-getaddrinfo4: \
   $(common-objpfx)resolv/libresolv.so $(shared-thread-library)
 $(objpfx)tst-getaddrinfo5: \
   $(common-objpfx)resolv/libresolv.so $(shared-thread-library)
+$(objpfx)bug-erange: \
+  $(common-objpfx)resolv/libresolv.so $(shared-thread-library)
 
 $(objpfx)tst-default-domain: $(objpfx)nisdomain.os
 
diff --git a/nss/bug-erange.c b/nss/bug-erange.c
index b709418b5cf..04b0a40c9ab 100644
--- a/nss/bug-erange.c
+++ b/nss/bug-erange.c
@@ -1,52 +1,70 @@
-/* Test case for gethostbyname_r bug when buffer expansion required.  */
+/* Test case for gethostbyname_r bug when buffer expansion required.
+   Copyright (C) 2004-2026 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <https://www.gnu.org/licenses/>.  */
 
-#include <netdb.h>
-#include <arpa/inet.h>
 #include <errno.h>
-#include <string.h>
-#include <stdio.h>
+#include <netdb.h>
 #include <stdlib.h>
-#include <unistd.h>
+#include <arpa/nameser.h>
+#include <support/check.h>
+#include <support/resolv_test.h>
+#include <support/support.h>
 
-int
-main (void)
+static void
+response (const struct resolv_response_context *ctx,
+          struct resolv_response_builder *b,
+          const char *qname, uint16_t qclass, uint16_t qtype)
 {
-  const char *host = "www.gnu.org";
+  resolv_response_init (b, (struct resolv_response_flags) { });
+  resolv_response_add_question (b, qname, qclass, qtype);
+  resolv_response_section (b, ns_s_an);
+  resolv_response_open_record (b, qname, qclass, qtype, 0);
+  resolv_response_add_data (b, "\xc0\x00\x02\x01", 4);
+  resolv_response_close_record (b);
+}
 
-  /* This code approximates the example code in the library manual.  */
+static int
+do_test (void)
+{
+  struct resolv_test *obj = resolv_test_start
+    ((struct resolv_redirect_config) { .response_callback = response });
 
   struct hostent hostbuf, *hp;
-  size_t hstbuflen;
-  char *tmphstbuf;
-  int res;
-  int herr;
+  char *buf;
+  size_t buflen = 1;            /* Make it way small to ensure ERANGE.  */
+  int res, herr;
 
-  hstbuflen = 16;		/* Make it way small to ensure ERANGE.  */
-  /* Allocate buffer, remember to free it to avoid memory leakage.  */
-  tmphstbuf = malloc (hstbuflen);
-
-  while ((res = gethostbyname_r (host, &hostbuf, tmphstbuf, hstbuflen,
+  buf = xmalloc (buflen);
+  while ((res = gethostbyname_r ("example.net", &hostbuf, buf, buflen,
                                  &hp, &herr)) == ERANGE)
     {
-      /* Enlarge the buffer.  */
-      hstbuflen *= 2;
-      tmphstbuf = realloc (tmphstbuf, hstbuflen);
+      buflen *= 2;
+      buf = xrealloc (buf, buflen);
     }
 
-  if (res != 0 || hp == NULL)
-    {
-      printf ("gethostbyname_r failed: %s (errno: %m)\n", strerror (res));
+  TEST_COMPARE (res, 0);
+  TEST_VERIFY_EXIT (hp != NULL);
+  TEST_COMPARE (hp->h_addrtype, AF_INET);
+  TEST_COMPARE (hp->h_length, 4);
+  TEST_COMPARE_BLOB (hp->h_addr_list[0], 4, "\xc0\x00\x02\x01", 4);
 
-      if (access ("/etc/resolv.conf", R_OK))
-	{
-	  puts ("DNS probably not set up");
-	  return 0;
-	}
-
-      return 1;
-    }
-
-  printf ("Got: %s %s\n", hp->h_name,
-	  inet_ntoa (*(struct in_addr *) hp->h_addr));
+  free (buf);
+  resolv_test_end (obj);
   return 0;
 }
+
+#include <support/test-driver.c>
-- 
2.43.0