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, 10 insertions, 8 deletions

diff --git a/sql/create_options.h b/sql/create_options.h
index 191ec88750a..41e8abcb232 100644
--- a/sql/create_options.h
+++ b/sql/create_options.h
@@ -29,8 +29,8 @@ enum { ENGINE_OPTION_MAX_LENGTH=32767 };
 class engine_option_value: public Sql_alloc
 {
  public:
-  LEX_STRING name;
-  LEX_STRING value;
+  LEX_CSTRING name;
+  LEX_CSTRING value;
   engine_option_value *next;    ///< parser puts them in a FIFO linked list
   bool parsed;                  ///< to detect unrecognized options
   bool quoted_value;            ///< option=VAL vs. option='VAL'
@@ -42,28 +42,30 @@ class engine_option_value: public Sql_alloc
   {
     link(start, end);
   }
-  engine_option_value(LEX_STRING &name_arg, LEX_STRING &value_arg, bool quoted,
+  engine_option_value(LEX_CSTRING &name_arg, LEX_CSTRING &value_arg,
+                      bool quoted,
                       engine_option_value **start, engine_option_value **end) :
     name(name_arg), value(value_arg),
     next(NULL), parsed(false), quoted_value(quoted)
   {
     link(start, end);
   }
-  engine_option_value(LEX_STRING &name_arg,
+  engine_option_value(LEX_CSTRING &name_arg,
                       engine_option_value **start, engine_option_value **end) :
-    name(name_arg), value(null_lex_str),
+    name(name_arg), value(null_clex_str),
     next(NULL), parsed(false), quoted_value(false)
   {
     link(start, end);
   }
-  engine_option_value(LEX_STRING &name_arg, ulonglong value_arg,
+  engine_option_value(LEX_CSTRING &name_arg, ulonglong value_arg,
                       engine_option_value **start, engine_option_value **end,
                       MEM_ROOT *root) :
     name(name_arg), next(NULL), parsed(false), quoted_value(false)
   {
-    if ((value.str= (char *)alloc_root(root, 22)))
+    char *str;
+    if ((value.str= str= (char *)alloc_root(root, 22)))
     {
-      value.length= longlong10_to_str(value_arg, value.str, 10) - value.str;
+      value.length= longlong10_to_str(value_arg, str, 10) - str;
       link(start, end);
     }
   }