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, 6 insertions, 6 deletions

diff --git a/sql/rpl_utility.cc b/sql/rpl_utility.cc
index bdf5b7dea80..9a984c5c953 100644
--- a/sql/rpl_utility.cc
+++ b/sql/rpl_utility.cc
@@ -825,7 +825,7 @@ table_def::compatible_with(THD *thd, rpl_group_info *rgi,
     {
       DBUG_PRINT("debug", ("Checking column %d -"
                            " field '%s' can be converted - order: %d",
-                           col, field->field_name, order));
+                           col, field->field_name.str, order));
       DBUG_ASSERT(order >= -1 && order <= 1);
 
       /*
@@ -855,7 +855,7 @@ table_def::compatible_with(THD *thd, rpl_group_info *rgi,
     {
       DBUG_PRINT("debug", ("Checking column %d -"
                            " field '%s' can not be converted",
-                           col, field->field_name));
+                           col, field->field_name.str));
       DBUG_ASSERT(col < size() && col < table->s->fields);
       DBUG_ASSERT(table->s->db.str && table->s->table_name.str);
       DBUG_ASSERT(table->in_use);
@@ -891,7 +891,7 @@ table_def::compatible_with(THD *thd, rpl_group_info *rgi,
         table->field[col]->sql_type(target_type);
         DBUG_PRINT("debug", ("Field %s - conversion required."
                              " Source type: '%s', Target type: '%s'",
-                             tmp_table->field[col]->field_name,
+                             tmp_table->field[col]->field_name.str,
                              source_type.c_ptr_safe(), target_type.c_ptr_safe()));
       }
   }
@@ -928,7 +928,7 @@ public:
                       (int) sql_type,
                       target_field->table->s->db.str,
                       target_field->table->s->table_name.str,
-                      target_field->field_name);
+                      target_field->field_name.str);
       return true;
     }
     Field *tmp= handler->make_conversion_table_field(this, metadata,
@@ -938,7 +938,7 @@ public:
     Virtual_tmp_table::add(tmp);
     DBUG_PRINT("debug", ("sql_type: %d, target_field: '%s', max_length: %d, decimals: %d,"
                          " maybe_null: %d, unsigned_flag: %d, pack_length: %u",
-                         sql_type, target_field->field_name,
+                         sql_type, target_field->field_name.str,
                          tmp->field_length, tmp->decimals(), TRUE,
                          tmp->flags, tmp->pack_length()));
     return false;
@@ -980,7 +980,7 @@ TABLE *table_def::create_conversion_table(THD *thd, rpl_group_info *rgi,
       DBUG_PRINT("debug", ("binlog_type: %d, metadata: %04X, target_field: '%s'"
                            " make_conversion_table_field() failed",
                            binlog_type(col), field_metadata(col),
-                           target_table->field[col]->field_name));
+                           target_table->field[col]->field_name.str));
       goto err;
     }
   }