Changing field::field_name and Item::name to LEX_CSTRING

Benefits of this patch:
- Removed a lot of calls to strlen(), especially for field_string
- Strings generated by parser are now const strings, less chance of
  accidently changing a string
- Removed a lot of calls with LEX_STRING as parameter (changed to pointer)
- More uniform code
- Item::name_length was not kept up to date. Now fixed
- Several bugs found and fixed (Access to null pointers,
  access of freed memory, wrong arguments to printf like functions)
- Removed a lot of casts from (const char*) to (char*)

Changes:
- This caused some ABI changes
  - lex_string_set now uses LEX_CSTRING
  - Some fucntions are now taking const char* instead of char*
- Create_field::change and after changed to LEX_CSTRING
- handler::connect_string, comment and engine_name() changed to LEX_CSTRING
- Checked printf() related calls to find bugs. Found and fixed several
  errors in old code.
- A lot of changes from LEX_STRING to LEX_CSTRING, especially related to
  parsing and events.
- Some changes from LEX_STRING and LEX_STRING & to LEX_CSTRING*
- Some changes for char* to const char*
- Added printf argument checking for my_snprintf()
- Introduced null_clex_str, star_clex_string, temp_lex_str to simplify
  code
- Added item_empty_name and item_used_name to be able to distingush between
  items that was given an empty name and items that was not given a name
  This is used in sql_yacc.yy to know when to give an item a name.
- select table_name."*' is not anymore same as table_name.*
- removed not used function Item::rename()
- Added comparision of item->name_length before some calls to
  my_strcasecmp() to speed up comparison
- Moved Item_sp_variable::make_field() from item.h to item.cc
- Some minimal code changes to avoid copying to const char *
- Fixed wrong error message in wsrep_mysql_parse()
- Fixed wrong code in find_field_in_natural_join() where real_item() was
  set when it shouldn't
- ER_ERROR_ON_RENAME was used with extra arguments.
- Removed some (wrong) ER_OUTOFMEMORY, as alloc_root will already
  give the error.

TODO:
- Check possible unsafe casts in plugin/auth_examples/qa_auth_interface.c
- Change code to not modify LEX_CSTRING for database name
  (as part of lower_case_table_names)

1 files changed, 5 insertions, 6 deletions

diff --git a/sql/event_parse_data.cc b/sql/event_parse_data.cc
index 2cd8f5c1b59..7932f228309 100644
--- a/sql/event_parse_data.cc
+++ b/sql/event_parse_data.cc
@@ -528,7 +528,7 @@ Event_parse_data::init_definer(THD *thd)
   const char *definer_host= thd->lex->definer->host.str;
   size_t  definer_user_len= thd->lex->definer->user.length;
   size_t  definer_host_len= thd->lex->definer->host.length;
-
+  char *tmp;
   DBUG_PRINT("info",("init definer_user thd->mem_root: 0x%lx  "
                      "definer_user: 0x%lx", (long) thd->mem_root,
                      (long) definer_user));
@@ -536,15 +536,14 @@ Event_parse_data::init_definer(THD *thd)
   /* + 1 for @ */
   DBUG_PRINT("info",("init definer as whole"));
   definer.length= definer_user_len + definer_host_len + 1;
-  definer.str= (char*) thd->alloc(definer.length + 1);
+  definer.str= tmp= (char*) thd->alloc(definer.length + 1);
 
   DBUG_PRINT("info",("copy the user"));
-  memcpy(definer.str, definer_user, definer_user_len);
-  definer.str[definer_user_len]= '@';
+  strmake(tmp, definer_user, definer_user_len);
+  tmp[definer_user_len]= '@';
 
   DBUG_PRINT("info",("copy the host"));
-  memcpy(definer.str + definer_user_len + 1, definer_host, definer_host_len);
-  definer.str[definer.length]= '\0';
+  strmake(tmp + definer_user_len + 1, definer_host, definer_host_len);
   DBUG_PRINT("info",("definer [%s] initted", definer.str));
 
   DBUG_VOID_RETURN;