Reduce usage of strlen()

Changes:
- To detect automatic strlen() I removed the methods in String that
  uses 'const char *' without a length:
  - String::append(const char*)
  - Binary_string(const char *str)
  - String(const char *str, CHARSET_INFO *cs)
  - append_for_single_quote(const char *)
  All usage of append(const char*) is changed to either use
  String::append(char), String::append(const char*, size_t length) or
  String::append(LEX_CSTRING)
- Added STRING_WITH_LEN() around constant string arguments to
  String::append()
- Added overflow argument to escape_string_for_mysql() and
  escape_quotes_for_mysql() instead of returning (size_t) -1 on overflow.
  This was needed as most usage of the above functions never tested the
  result for -1 and would have given wrong results or crashes in case
  of overflows.
- Added Item_func_or_sum::func_name_cstring(), which returns LEX_CSTRING.
  Changed all Item_func::func_name()'s to func_name_cstring()'s.
  The old Item_func_or_sum::func_name() is now an inline function that
  returns func_name_cstring().str.
- Changed Item::mode_name() and Item::func_name_ext() to return
  LEX_CSTRING.
- Changed for some functions the name argument from const char * to
  to const LEX_CSTRING &:
  - Item::Item_func_fix_attributes()
  - Item::check_type_...()
  - Type_std_attributes::agg_item_collations()
  - Type_std_attributes::agg_item_set_converter()
  - Type_std_attributes::agg_arg_charsets...()
  - Type_handler_hybrid_field_type::aggregate_for_result()
  - Type_handler_geometry::check_type_geom_or_binary()
  - Type_handler::Item_func_or_sum_illegal_param()
  - Predicant_to_list_comparator::add_value_skip_null()
  - Predicant_to_list_comparator::add_value()
  - cmp_item_row::prepare_comparators()
  - cmp_item_row::aggregate_row_elements_for_comparison()
  - Cursor_ref::print_func()
- Removes String_space() as it was only used in one cases and that
  could be simplified to not use String_space(), thanks to the fixed
  my_vsnprintf().
- Added some const LEX_CSTRING's for common strings:
  - NULL_clex_str, DATA_clex_str, INDEX_clex_str.
- Changed primary_key_name to a LEX_CSTRING
- Renamed String::set_quick() to String::set_buffer_if_not_allocated() to
  clarify what the function really does.
- Rename of protocol function:
  bool store(const char *from, CHARSET_INFO *cs) to
  bool store_string_or_null(const char *from, CHARSET_INFO *cs).
  This was done to both clarify the difference between this 'store' function
  and also to make it easier to find unoptimal usage of store() calls.
- Added Protocol::store(const LEX_CSTRING*, CHARSET_INFO*)
- Changed some 'const char*' arrays to instead be of type LEX_CSTRING.
- class Item_func_units now used LEX_CSTRING for name.

Other things:
- Fixed a bug in mysql.cc:construct_prompt() where a wrong escape character
  in the prompt would cause some part of the prompt to be duplicated.
- Fixed a lot of instances where the length of the argument to
  append is known or easily obtain but was not used.
- Removed some not needed 'virtual' definition for functions that was
  inherited from the parent. I added override to these.
- Fixed Ordered_key::print() to preallocate needed buffer. Old code could
  case memory overruns.
- Simplified some loops when adding char * to a String with delimiters.

1 files changed, 7 insertions, 7 deletions

diff --git a/sql/sql_truncate.cc b/sql/sql_truncate.cc
index ab1ce65bae5..6ab644eb3ce 100644
--- a/sql/sql_truncate.cc
+++ b/sql/sql_truncate.cc
@@ -49,7 +49,7 @@ static bool fk_info_append_fields(THD *thd, String *str,
   while ((field= it++))
   {
     res|= append_identifier(thd, str, field);
-    res|= str->append(", ");
+    res|= str->append(STRING_WITH_LEN(", "));
   }
 
   str->chop();
@@ -81,17 +81,17 @@ static const char *fk_info_str(THD *thd, FOREIGN_KEY_INFO *fk_info)
   */
 
   res|= append_identifier(thd, &str, fk_info->foreign_db);
-  res|= str.append(".");
+  res|= str.append('.');
   res|= append_identifier(thd, &str, fk_info->foreign_table);
-  res|= str.append(", CONSTRAINT ");
+  res|= str.append(STRING_WITH_LEN(", CONSTRAINT "));
   res|= append_identifier(thd, &str, fk_info->foreign_id);
-  res|= str.append(" FOREIGN KEY (");
+  res|= str.append(STRING_WITH_LEN(" FOREIGN KEY ("));
   res|= fk_info_append_fields(thd, &str, &fk_info->foreign_fields);
-  res|= str.append(") REFERENCES ");
+  res|= str.append(STRING_WITH_LEN(") REFERENCES "));
   res|= append_identifier(thd, &str, fk_info->referenced_db);
-  res|= str.append(".");
+  res|= str.append('.');
   res|= append_identifier(thd, &str, fk_info->referenced_table);
-  res|= str.append(" (");
+  res|= str.append(STRING_WITH_LEN(" ("));
   res|= fk_info_append_fields(thd, &str, &fk_info->referenced_fields);
   res|= str.append(')');