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, 5 deletions

diff --git a/sql/sql_window.cc b/sql/sql_window.cc
index 557c7503306..ac70d3d0f32 100644
--- a/sql/sql_window.cc
+++ b/sql/sql_window.cc
@@ -12,13 +12,13 @@ Window_spec::check_window_names(List_iterator_fast<Window_spec> &it)
 {
   if (window_names_are_checked)
     return false;
-  char *name= this->name();
-  char *ref_name= window_reference();
+  const char *name= this->name();
+  const char *ref_name= window_reference();
   it.rewind();
   Window_spec *win_spec;
   while((win_spec= it++) && win_spec != this)
   {
-    char *win_spec_name= win_spec->name();
+    const char *win_spec_name= win_spec->name();
     if (!win_spec_name)
       break;
     if (name && my_strcasecmp(system_charset_info, name, win_spec_name) == 0)
@@ -384,8 +384,8 @@ int compare_window_frame_bounds(Window_frame_bound *win_frame_bound1,
       return CMP_EQ;
     else
     {
-      res= strcmp(win_frame_bound1->offset->name,
-                  win_frame_bound2->offset->name);
+      res= strcmp(win_frame_bound1->offset->name.str,
+                  win_frame_bound2->offset->name.str);
       res= res > 0 ? CMP_GT : CMP_LT;
       if (is_bottom_bound)
         res= -res;