Fixed host name comparison (still Bug #17582)

mysql-test/r/ndb_config.result:
  test case for Bug #17582
mysql-test/t/ndb_config.test:
  test case for Bug #17582
ndb/tools/ndb_config.cpp:
  gethostname() returns a pointer to a static buffer so we 
  need to create a copy of the results before calling it on
  the 2nd host name, else we're effectively comparing a 
  hostname to itself which is of course always true
  (Bug #17582)

mysql-test/r/ndb_config.result

@@ -9,3 +9,6 @@ ndbd,1,localhost ndbd,2,localhost ndbd,3,localhost ndbd,4,localhost ndb_mgmd,5,l
 ndbd,2,localhost ndbd,3,localhost ndbd,4,localhost ndbd,5,localhost ndb_mgmd,6,localhost mysqld,1, mysqld,7, mysqld,8, mysqld,9, mysqld,10,
 ndbd,3,localhost ndbd,4,localhost ndbd,5,localhost ndbd,6,localhost ndb_mgmd,1,localhost ndb_mgmd,2,localhost mysqld,11, mysqld,12, mysqld,13, mysqld,14, mysqld,15,
 shm,3,4,35,3 shm,3,5,35,3 shm,3,6,35,3 shm,4,5,35,4 shm,4,6,35,4 shm,5,6,35,5 tcp,11,3,55,3 tcp,11,4,55,4 tcp,11,5,55,5 tcp,11,6,55,6 tcp,12,3,55,3 tcp,12,4,55,4 tcp,12,5,55,5 tcp,12,6,55,6 tcp,13,3,55,3 tcp,13,4,55,4 tcp,13,5,55,5 tcp,13,6,55,6 tcp,14,3,55,3 tcp,14,4,55,4 tcp,14,5,55,5 tcp,14,6,55,6 tcp,15,3,55,3 tcp,15,4,55,4 tcp,15,5,55,5 tcp,15,6,55,6 tcp,1,3,55,1 tcp,1,4,55,1 tcp,1,5,55,1 tcp,1,6,55,1 tcp,2,3,55,2 tcp,2,4,55,2 tcp,2,5,55,2 tcp,2,6,55,2
+1 2 3
+
+1 2 3

mysql-test/t/ndb_config.test

@@ -16,3 +16,8 @@
 --exec $NDB_TOOLS_DIR/ndb_config --defaults-group-suffix=.cluster1 --defaults-file=$MYSQL_TEST_DIR/std_data/ndb_config_mycnf2.cnf --query=type,nodeid,host --mycnf 2> /dev/null
 --exec $NDB_TOOLS_DIR/ndb_config --defaults-group-suffix=.cluster2 --defaults-file=$MYSQL_TEST_DIR/std_data/ndb_config_mycnf2.cnf --query=type,nodeid,host --mycnf 2> /dev/null
 --exec $NDB_TOOLS_DIR/ndb_config --defaults-group-suffix=.cluster2 --defaults-file=$MYSQL_TEST_DIR/std_data/ndb_config_mycnf2.cnf --ndb-shm --connections --query=type,nodeid1,nodeid2,group,nodeidserver --mycnf 2> /dev/null
+
+
+--exec $NDB_TOOLS_DIR/ndb_config --no-defaults --query=nodeid --host=localhost --config-file=$NDB_BACKUP_DIR/config.ini 2> /dev/null
+--exec $NDB_TOOLS_DIR/ndb_config --no-defaults --query=nodeid --host=1.2.3.4   --config-file=$NDB_BACKUP_DIR/config.ini 2> /dev/null
+--exec $NDB_TOOLS_DIR/ndb_config --no-defaults --query=nodeid --host=127.0.0.1 --config-file=$NDB_BACKUP_DIR/config.ini 2> /dev/null

ndb/tools/ndb_config.cpp

@@ -411,28 +411,43 @@ HostMatch::eval(const Iter& iter)
   
   if(iter.get(m_key, &valc) == 0)
   {
-	  struct hostent *h1, *h2;
+	  struct hostent *h1, *h2, copy1;
+	  char *addr1;
+	  int stat;
 
 	  h1 = gethostbyname(m_value.c_str());
 	  if (h1 == NULL) {
 		  return 0;
 	  }
 
+	  // gethostbyname returns a pointer to a static structure
+	  // so we need to copy the results before doing the next call
+	  memcpy(&copy1, h1, sizeof(struct hostent));
+	  addr1 = (char *)malloc(copy1.h_length);
+	  memcpy(addr1, h1->h_addr, copy1.h_length);
+
 	  h2 = gethostbyname(valc);
 	  if (h2 == NULL) {
+		  free(addr1);
 		  return 0;
 	  }
 
-	  if (h1->h_addrtype != h2->h_addrtype) {
+	  if (copy1.h_addrtype != h2->h_addrtype) {
+		  free(addr1);
 		  return 0;
 	  }
 
-	  if (h1->h_length != h2->h_length) 
+	  if (copy1.h_length != h2->h_length) 
 	  {
+		  free(addr1);
 		  return 0;
 	  }
 	  
-	  return 0 == memcmp(h1->h_addr, h2->h_addr, h1->h_length);
+	  stat = memcmp(addr1, h2->h_addr, copy1.h_length);
+	  
+	  free(addr1);
+	  
+	  return (stat == 0);
   }
 
   return 0;