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, 9 insertions, 8 deletions

diff --git a/sql/sql_acl.cc b/sql/sql_acl.cc
index 82ee92c27ba..7a048ea45a0 100644
--- a/sql/sql_acl.cc
+++ b/sql/sql_acl.cc
@@ -453,15 +453,15 @@ public:
   void print_grant(String *str)
   {
     str->append(STRING_WITH_LEN("GRANT PROXY ON '"));
-    str->append(proxied_user);
+    str->append(proxied_user, strlen(proxied_user));
     str->append(STRING_WITH_LEN("'@'"));
     if (proxied_host.hostname)
       str->append(proxied_host.hostname, strlen(proxied_host.hostname));
     str->append(STRING_WITH_LEN("' TO '"));
-    str->append(user);
+    str->append(user, strlen(user));
     str->append(STRING_WITH_LEN("'@'"));
     if (host.hostname)
-      str->append(host.hostname);
+      str->append(host.hostname, strlen(host.hostname));
     str->append(STRING_WITH_LEN("'"));
     if (with_grant)
       str->append(STRING_WITH_LEN(" WITH GRANT OPTION"));
@@ -1776,7 +1776,7 @@ class User_table_json: public User_table
       if (value_len)
         json.append(',');
       json.append('"');
-      json.append(key);
+      json.append(key, strlen(key));
       json.append(STRING_WITH_LEN("\":"));
       if (string)
         json.append('"');
@@ -9136,7 +9136,7 @@ bool mysql_show_create_user(THD *thd, LEX_USER *lex_user)
     goto end;
   }
 
-  result.append("CREATE USER ");
+  result.append(STRING_WITH_LEN("CREATE USER "));
   append_identifier(thd, &result, username, strlen(username));
   add_user_parameters(thd, &result, acl_user, false);
 
@@ -9160,9 +9160,10 @@ bool mysql_show_create_user(THD *thd, LEX_USER *lex_user)
    of a user account, including both the manual expiration state of the
    account and the automatic expiration policy attached to it, we should
    print two statements here, a CREATE USER (printed above) and an ALTER USER */
-  if (acl_user->password_expired && acl_user->password_lifetime > -1) {
+  if (acl_user->password_expired && acl_user->password_lifetime > -1)
+  {
     result.length(0);
-    result.append("ALTER USER ");
+    result.append(STRING_WITH_LEN("ALTER USER "));
     append_identifier(thd, &result, username, strlen(username));
     result.append('@');
     append_identifier(thd, &result, acl_user->host.hostname,
@@ -9418,7 +9419,7 @@ static bool show_default_role(THD *thd, ACL_USER *acl_entry,
     def_str.length(0);
     def_str.append(STRING_WITH_LEN("SET DEFAULT ROLE "));
     def_str.append(&def_rolename);
-    def_str.append(" FOR '");
+    def_str.append(STRING_WITH_LEN(" FOR '"));
     def_str.append(&acl_entry->user);
     DBUG_ASSERT(!(acl_entry->flags & IS_ROLE));
     def_str.append(STRING_WITH_LEN("'@'"));