Change TABLE->alias to String for less memory reallocation

Changed some String.ptr() -> String.c_ptr() for String that are not guaranteed to end with \0
Removed some c_ptr() usage from parameters to functions that takes ptr & length
Use preallocate buffers to avoid calling malloc() for most operations. 


sql/event_db_repository.cc:
  alias is now a String
sql/event_scheduler.cc:
  c_ptr -> c_ptr_safe() to avoid warnings from valgrind.
sql/events.cc:
  c_ptr -> c_ptr_safe() to avoid warnings from valgrind.
  c_ptr -> ptr() as function takes ptr & length
sql/field.cc:
  alias is now a String
sql/field.h:
  alias is now a String
sql/ha_partition.cc:
  alias is now a String
sql/handler.cc:
  alias is now a String
  ptr() -> c_ptr() as string is not guaranteed to be \0 terminated
sql/item.cc:
  Store error parameter in separarte buffer to ensure correct error message
sql/item_func.cc:
  ptr() -> c_ptr_safe() as string is not guaranteed to be \0 terminated
sql/item_sum.h:
  Use my_strtod() instead of my_atof() to not have to make string \0 terminated
sql/lock.cc:
  alias is now a String
sql/log.cc:
  c_ptr() -> ptr() as function takes ptr & length
sql/log_event.cc:
  c_ptr_quick() -> ptr() as we only want to get the pointer to String buffer
sql/opt_range.cc:
  ptr() -> c_ptr() as string is not guaranteed to be \0 terminated
sql/opt_table_elimination.cc:
  alias is now a String
sql/set_var.cc:
  ptr() -> c_ptr() as string is not guaranteed to be \0 terminated
  c_ptr() -> c_ptr_safe() to avoid warnings from valgrind.
  c_ptr() -> ptr() as function takes ptr & length
  Simplify some code.
sql/sp.cc:
  c_ptr() -> ptr() as function takes ptr & length
sql/sp_rcontext.cc:
  alias is now a String
sql/sql_base.cc:
  alias is now a String.
  Here we win a realloc() for most alias usage.
sql/sql_class.cc:
  Use size descriptor for printf() to avoid accessing bytes outside of buffer
sql/sql_insert.cc:
  Change allocation of TABLE as it's now contains a String
  _ptr() -> ptr() as function takes ptr & length
sql/sql_load.cc:
  Use preallocate buffers to avoid calling malloc() for most operations.
sql/sql_parse.cc:
  Use c_ptr_safe() to ensure string is \0 terminated.
sql/sql_plugin.cc:
  c_ptr_quick() -> ptr() as function takes ptr & length
sql/sql_select.cc:
  alias is now a String
sql/sql_show.cc:
  alias is now a String
sql/sql_string.h:
  Added move() function to change who owns the string (owner does the free)
sql/sql_table.cc:
  alias is now a String
  c_ptr() -> c_ptr_safe() to avoid warnings from valgrind.
sql/sql_test.cc:
  c_ptr() -> c_ptr_safe() to avoid warnings from valgrind.
  alias is now a String
sql/sql_trigger.cc:
  c_ptr() -> c_ptr_safe() to avoid warnings from valgrind.
  Use field->init() to setup pointers to alias.
sql/sql_update.cc:
  alias is now a String
sql/sql_view.cc:
  ptr() -> c_ptr_safe() as string is not guaranteed to be \0 terminated
sql/sql_yacc.yy:
  r() -> c_ptr() as string is not guaranteed to be \0 terminated
sql/table.cc:
  alias is now a String
sql/table.h:
  alias is now a String
storage/federatedx/ha_federatedx.cc:
  Remove extra 1 byte alloc that is automaticly done by strmake()
  Ensure that error message ends with \0
storage/maria/ha_maria.cc:
  alias is now a String
storage/myisam/ha_myisam.cc:
  alias is now a String

sql/sql_load.cc

@@ -604,11 +604,15 @@ static bool write_execute_load_query_log_event(THD *thd, sql_exchange* ex,
   size_t               pl= 0;
   List<Item>           fv;
   Item                *item, *val;
-  String               pfield, pfields;
   int                  n;
   const char          *tbl= table_name_arg;
   const char          *tdb= (thd->db != NULL ? thd->db : db_arg);
-  String              string_buf;
+  char 		      name_buffer[SAFE_NAME_LEN*2];
+  char                command_buffer[1024];
+  String              string_buf(name_buffer, sizeof(name_buffer),
+                                 system_charset_info);
+  String              pfields(command_buffer, sizeof(command_buffer),
+                              system_charset_info);
 
   if (!thd->db || strcmp(db_arg, thd->db)) 
   {
@@ -617,7 +621,7 @@ static bool write_execute_load_query_log_event(THD *thd, sql_exchange* ex,
       prefix table name with database name so that it 
       becomes a FQ name.
      */
-    string_buf.set_charset(system_charset_info);
+    string_buf.length(0);
     string_buf.append(db_arg);
     string_buf.append("`");
     string_buf.append(".");
@@ -638,6 +642,7 @@ static bool write_execute_load_query_log_event(THD *thd, sql_exchange* ex,
   /*
     prepare fields-list and SET if needed; print_query won't do that for us.
   */
+  pfields.length(0);
   if (!thd->lex->field_list.is_empty())
   {
     List_iterator<Item>  li(thd->lex->field_list);
@@ -682,8 +687,8 @@ static bool write_execute_load_query_log_event(THD *thd, sql_exchange* ex,
     }
   }
 
-  p= pfields.c_ptr_safe();
-  pl= strlen(p);
+  p=  pfields.c_ptr_safe();
+  pl= pfields.length();
 
   if (!(load_data_query= (char *)thd->alloc(lle.get_query_buffer_length() + 1 + pl)))
     return TRUE;