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, 9 insertions, 8 deletions

diff --git a/sql/parse_file.h b/sql/parse_file.h
index 87917dbd71b..3f48b2072db 100644
--- a/sql/parse_file.h
+++ b/sql/parse_file.h
@@ -42,7 +42,7 @@ enum file_opt_type {
 
 struct File_option
 {
-  LEX_STRING name;              /**< Name of the option */
+  LEX_CSTRING name;             /**< Name of the option */
   my_ptrdiff_t offset;          /**< offset to base address of value */
   file_opt_type type;           /**< Option type */
 };
@@ -82,15 +82,16 @@ bool get_file_options_ulllist(const char *&ptr, const char *end,
 
 const char *
 parse_escaped_string(const char *ptr, const char *end, MEM_ROOT *mem_root,
-                     LEX_STRING *str);
+                     LEX_CSTRING *str);
 
 class File_parser;
-File_parser *sql_parse_prepare(const LEX_STRING *file_name,
+File_parser *sql_parse_prepare(const LEX_CSTRING *file_name,
 			       MEM_ROOT *mem_root, bool bad_format_errors);
 
 my_bool
-sql_create_definition_file(const LEX_STRING *dir, const  LEX_STRING *file_name,
-			   const LEX_STRING *type,
+sql_create_definition_file(const LEX_CSTRING *dir,
+                           const LEX_CSTRING *file_name,
+			   const LEX_CSTRING *type,
 			   uchar* base, File_option *parameters);
 my_bool rename_in_schema_file(THD *thd,
                               const char *schema, const char *old_name,
@@ -99,19 +100,19 @@ my_bool rename_in_schema_file(THD *thd,
 class File_parser: public Sql_alloc
 {
   char *start, *end;
-  LEX_STRING file_type;
+  LEX_CSTRING file_type;
   bool content_ok;
 public:
   File_parser() :start(0), end(0), content_ok(0)
     { file_type.str= 0; file_type.length= 0; }
 
   bool ok() { return content_ok; }
-  const LEX_STRING *type() const { return &file_type; }
+  const LEX_CSTRING *type() const { return &file_type; }
   my_bool parse(uchar* base, MEM_ROOT *mem_root,
 		struct File_option *parameters, uint required,
                 Unknown_key_hook *hook) const;
 
-  friend File_parser *sql_parse_prepare(const LEX_STRING *file_name,
+  friend File_parser *sql_parse_prepare(const LEX_CSTRING *file_name,
 					MEM_ROOT *mem_root,
 					bool bad_format_errors);
 };