maint.mk: restore functionality removed by recent change

[gnulib.git] / lib / canon-host.c

diff --git a/lib/canon-host.c b/lib/canon-host.c
index 56e84a7..d610689 100644 (file)
--- a/lib/canon-host.c
+++ b/lib/canon-host.c
@@ -1,56 +1,45 @@
 /* Host name canonicalization
 
-   Copyright (C) 2005 Free Software
-   Foundation, Inc.
+   Copyright (C) 2005-2013 Free Software Foundation, Inc.
 
    Written by Derek Price <derek@ximbiot.com>.
 
-   This program is free software; you can redistribute it and/or
-   modify it under the terms of the GNU General Public License as
-   published by the Free Software Foundation; either version 2, or (at
-   your option) any later version.
+   This program is free software: you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 3, or (at your option)
+   any later version.
 
-   This program 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
-   General Public License for more details.
+   This program 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 General Public License for more details.
 
    You should have received a copy of the GNU General Public License
-   along with this program; if not, write to the Free Software Foundation,
-   Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.  */
+   along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
 
-#ifdef HAVE_CONFIG_H
-# include <config.h>
-#endif
+#include <config.h>
 
 #include "canon-host.h"
 
-#include "getaddrinfo.h"
-#include "strdup.h"
-
-
+#include <string.h>
+#include <netdb.h>
 
 /* Store the last error for the single-threaded version of this function.  */
 static int last_cherror;
 
-
-
 /* Single-threaded of wrapper for canon_host_r.  After a NULL return, error
-   messages may be retrieved via ch_strerror().
- */
+   messages may be retrieved via ch_strerror().  */
 char *
 canon_host (const char *host)
 {
-    return canon_host_r (host, &last_cherror);
+  return canon_host_r (host, &last_cherror);
 }
 
-
-
-/* Returns a malloc'd string containing the canonical hostname associated with
-   HOST, or NULL if a canonical name cannot be determined.  On NULL return, if
-   CHERROR is not NULL, *CHERROR will be set to an error code as returned by
-   getaddrinfo().  Error codes from CHERROR may be converted to a string
-   suitable for error messages by ch_strerror_r() or gai_strerror().
+/* Return a malloc'd string containing the canonical hostname associated with
+   HOST, or NULL if a canonical name cannot be determined.  On NULL return,
+   if CHERROR is not NULL, set *CHERROR to an error code as returned by
+   getaddrinfo().  Use ch_strerror_r() or gai_strerror() to convert a *CHERROR
+   value to a string suitable for error messages.
 
    WARNINGS
      HOST must be a string representation of a resolvable name for this host.
@@ -66,34 +55,36 @@ canon_host (const char *host)
      getaddrinfo spec <http://www.opengroup.org/susv3xsh/getaddrinfo.html">,
      RFC 1034 <http://www.faqs.org/rfcs/rfc1034.html>, & RFC 2181
      <http://www.faqs.org/rfcs/rfc2181.html> for more on what this confusing
-     term really refers to.
- */
+     term really refers to. */
 char *
 canon_host_r (char const *host, int *cherror)
 {
-    char *retval = NULL;
-    static struct addrinfo hints;
-    struct addrinfo *res = NULL;
-    int status;
-
-    hints.ai_flags = AI_CANONNAME;
-    status = getaddrinfo (host, NULL, &hints, &res);
-    if (!status)
+  char *retval = NULL;
+  static struct addrinfo hints;
+  struct addrinfo *res = NULL;
+  int status;
+
+  hints.ai_flags = AI_CANONNAME;
+  status = getaddrinfo (host, NULL, &hints, &res);
+  if (!status)
     {
-       retval = strdup (res->ai_canonname);
-       freeaddrinfo (res);
+      /* http://lists.gnu.org/archive/html/bug-coreutils/2006-09/msg00300.html
+         says Darwin 7.9.0 getaddrinfo returns 0 but sets
+         res->ai_canonname to NULL.  */
+      retval = strdup (res->ai_canonname ? res->ai_canonname : host);
+      if (!retval && cherror)
+        *cherror = EAI_MEMORY;
+      freeaddrinfo (res);
     }
-    else if (cherror)
-       *cherror = status;
+  else if (cherror)
+    *cherror = status;
 
-    return retval;
+  return retval;
 }
 
-
-
 /* Return a string describing the last error encountered by canon_host.  */
 const char *
 ch_strerror (void)
 {
-    return gai_strerror (last_cherror);
+  return gai_strerror (last_cherror);
 }