Backport of JimW's localhost patch to 4.1 tree.

Handle systems like default FC4 where 127.0.0.1 doesn't always map to 'localhost' first. 
(Bug #11822)

1 files changed, 9 insertions, 1 deletions

diff --git a/sql/hostname.cc b/sql/hostname.cc
index 39223556024..32e1d84fac3 100644
--- a/sql/hostname.cc
+++ b/sql/hostname.cc
@@ -130,15 +130,23 @@ void reset_host_errors(struct in_addr *in)
   VOID(pthread_mutex_unlock(&hostname_cache->lock));
 }
 
+/* Deal with systems that don't defined INADDR_LOOPBACK */
+#ifndef INADDR_LOOPBACK
+#define INADDR_LOOPBACK 0x7f000001UL
+#endif
 
 my_string ip_to_hostname(struct in_addr *in, uint *errors)
 {
   uint i;
   host_entry *entry;
   DBUG_ENTER("ip_to_hostname");
+  *errors= 0;
+
+  /* We always treat the loopback address as "localhost". */
+  if (in->s_addr == htonl(INADDR_LOOPBACK))
+    DBUG_RETURN((char *)my_localhost);
 
   /* Check first if we have name in cache */
-  *errors=0;
   if (!(specialflag & SPECIAL_NO_HOST_CACHE))
   {
     VOID(pthread_mutex_lock(&hostname_cache->lock));