Merge april.(none):/home/svoj/devel/mysql/BUG17917/mysql-4.1

into  april.(none):/home/svoj/devel/mysql/BUG17917/mysql-5.0

myisam/mi_packrec.c

@@ -1189,24 +1189,30 @@ my_bool _mi_memmap_file(MI_INFO *info)
   MYISAM_SHARE *share=info->s;
   DBUG_ENTER("mi_memmap_file");
 
-  if (!info->s->file_map)
+  if (!share->file_map)
   {
+    my_off_t data_file_length= share->state.state.data_file_length;
+    if (data_file_length > (my_off_t) (~((size_t) 0)) - MEMMAP_EXTRA_MARGIN)
+    {
+      DBUG_PRINT("warning", ("File is too large for mmap"));
+      DBUG_RETURN(0);
+    }
     if (my_seek(info->dfile,0L,MY_SEEK_END,MYF(0)) <
-	share->state.state.data_file_length+MEMMAP_EXTRA_MARGIN)
+        data_file_length + MEMMAP_EXTRA_MARGIN)
     {
       DBUG_PRINT("warning",("File isn't extended for memmap"));
       DBUG_RETURN(0);
     }
     file_map=(byte*)
-      my_mmap(0,(size_t)(share->state.state.data_file_length+MEMMAP_EXTRA_MARGIN),PROT_READ,
-	   MAP_SHARED | MAP_NORESERVE,info->dfile,0L);
+      my_mmap(0, (size_t) (data_file_length + MEMMAP_EXTRA_MARGIN), PROT_READ,
+              MAP_SHARED | MAP_NORESERVE, info->dfile, 0L);
     if (file_map == (byte*) MAP_FAILED)
     {
       DBUG_PRINT("warning",("mmap failed: errno: %d",errno));
       my_errno=errno;
       DBUG_RETURN(0);
     }
-    info->s->file_map=file_map;
+    share->file_map= file_map;
   }
   info->opt_flag|= MEMMAP_USED;
   info->read_record=share->read_record=_mi_read_mempack_record;

sql/mysqld.cc

@@ -5677,7 +5677,7 @@ The minimum value for this variable is 4096.",
     (gptr*) &max_system_variables.max_length_for_sort_data, 0, GET_ULONG,
     REQUIRED_ARG, 1024, 4, 8192*1024L, 0, 1, 0},
   {"max_prepared_stmt_count", OPT_MAX_PREPARED_STMT_COUNT,
-   "Maximum numbrer of prepared statements in the server.",
+   "Maximum number of prepared statements in the server.",
    (gptr*) &max_prepared_stmt_count, (gptr*) &max_prepared_stmt_count,
    0, GET_ULONG, REQUIRED_ARG, 16382, 0, 1*1024*1024, 0, 1, 0},
   {"max_relay_log_size", OPT_MAX_RELAY_LOG_SIZE,