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, 13 insertions, 7 deletions

diff --git a/sql/sql_alter.cc b/sql/sql_alter.cc
index 3592fa3cfbd..0194f26d217 100644
--- a/sql/sql_alter.cc
+++ b/sql/sql_alter.cc
@@ -50,7 +50,7 @@ Alter_info::Alter_info(const Alter_info &rhs, MEM_ROOT *mem_root)
 }
 
 
-bool Alter_info::set_requested_algorithm(const LEX_STRING *str)
+bool Alter_info::set_requested_algorithm(const LEX_CSTRING *str)
 {
   // To avoid adding new keywords to the grammar, we match strings here.
   if (!my_strcasecmp(system_charset_info, str->str, "INPLACE"))
@@ -65,7 +65,7 @@ bool Alter_info::set_requested_algorithm(const LEX_STRING *str)
 }
 
 
-bool Alter_info::set_requested_lock(const LEX_STRING *str)
+bool Alter_info::set_requested_lock(const LEX_CSTRING *str)
 {
   // To avoid adding new keywords to the grammar, we match strings here.
   if (!my_strcasecmp(system_charset_info, str->str, "NONE"))
@@ -95,10 +95,15 @@ Alter_table_ctx::Alter_table_ctx()
 {
 }
 
+/*
+  TODO: new_name_arg changes if lower case table names.
+  Should be copied or converted before call
+*/
 
 Alter_table_ctx::Alter_table_ctx(THD *thd, TABLE_LIST *table_list,
                                  uint tables_opened_arg,
-                                 char *new_db_arg, char *new_name_arg)
+                                 const char *new_db_arg,
+                                 const char *new_name_arg)
   : datetime_field(NULL), error_if_not_empty(false),
     tables_opened(tables_opened_arg),
     new_db(new_db_arg), new_name(new_name_arg),
@@ -126,13 +131,14 @@ Alter_table_ctx::Alter_table_ctx(THD *thd, TABLE_LIST *table_list,
 
     if (lower_case_table_names == 1) // Convert new_name/new_alias to lower case
     {
-      my_casedn_str(files_charset_info, new_name);
+      my_casedn_str(files_charset_info, (char*) new_name);
       new_alias= new_name;
     }
     else if (lower_case_table_names == 2) // Convert new_name to lower case
     {
-      strmov(new_alias= new_alias_buff, new_name);
-      my_casedn_str(files_charset_info, new_name);
+      new_alias= new_alias_buff;
+      strmov(new_alias_buff, new_name);
+      my_casedn_str(files_charset_info, (char*) new_name);
     }
     else
       new_alias= new_name; // LCTN=0 => case sensitive + case preserving
@@ -154,7 +160,7 @@ Alter_table_ctx::Alter_table_ctx(THD *thd, TABLE_LIST *table_list,
     new_name= table_name;
   }
 
-  my_snprintf(tmp_name, sizeof(tmp_name), "%s-%lx_%lx", tmp_file_prefix,
+  my_snprintf(tmp_name, sizeof(tmp_name), "%s-%lx_%llx", tmp_file_prefix,
               current_pid, thd->thread_id);
   /* Safety fix for InnoDB */
   if (lower_case_table_names)