Optimize LEX_STRING comparisons

- Added inline lex_string_cmp() to replace my_strcase_cmp().
- Added inline lex_string_eq to first compares lengths before comparing strings

14 files changed, 139 insertions, 139 deletions

diff --git a/sql/item.cc b/sql/item.cc
index e4fcaa42c6f..5840e4a4081 100644
--- a/sql/item.cc
+++ b/sql/item.cc
@@ -1184,8 +1184,7 @@ bool Item::eq(const Item *item, bool binary_cmp) const
     type() can be only among basic constant types.
   */
   return type() == item->type() && name.str && item->name.str &&
-    name.length == item->name.length &&
-    !my_strcasecmp(system_charset_info, name.str, item->name.str);
+    !lex_string_cmp(system_charset_info, &name, &item->name);
 }
 
 
@@ -3086,8 +3085,8 @@ bool Item_field::eq(const Item *item, bool binary_cmp) const
     (In cases where we would choose wrong we would have to generate a
     ER_NON_UNIQ_ERROR).
   */
-  return (!my_strcasecmp(system_charset_info, item_field->name.str,
-			 field_name.str) &&
+  return (!lex_string_cmp(system_charset_info, &item_field->name,
+                          &field_name) &&
 	  (!item_field->table_name || !table_name ||
 	   (!my_strcasecmp(table_alias_charset, item_field->table_name,
 			   table_name) &&
@@ -5030,8 +5029,8 @@ static Item** find_field_in_group_list(Item *find_item, ORDER *group_list)
     /* SELECT list element with explicit alias */
     if ((*(cur_group->item))->name.str &&
         !(*(cur_group->item))->is_autogenerated_name &&
-        !my_strcasecmp(system_charset_info,
-                       (*(cur_group->item))->name.str, field_name->str))
+        !lex_string_cmp(system_charset_info,
+                        &(*(cur_group->item))->name, field_name))
     {
       ++cur_match_degree;
     }
@@ -5046,8 +5045,8 @@ static Item** find_field_in_group_list(Item *find_item, ORDER *group_list)
 
       DBUG_ASSERT(l_field_name->str != 0);
 
-      if (!my_strcasecmp(system_charset_info,
-                         l_field_name->str, field_name->str))
+      if (!lex_string_cmp(system_charset_info,
+                          l_field_name, field_name))
         ++cur_match_degree;
       else
         continue;
@@ -9116,8 +9115,8 @@ bool Item_trigger_field::eq(const Item *item, bool binary_cmp) const
 {
   return item->type() == TRIGGER_FIELD_ITEM &&
          row_version == ((Item_trigger_field *)item)->row_version &&
-         !my_strcasecmp(system_charset_info, field_name.str,
-                        ((Item_trigger_field *)item)->field_name.str);
+         !lex_string_cmp(system_charset_info, &field_name,
+                         &((Item_trigger_field *)item)->field_name);
 }
 
 
diff --git a/sql/sp_head.cc b/sql/sp_head.cc
index c1a194ab9b9..ebd8dd5b8d2 100644
--- a/sql/sp_head.cc
+++ b/sql/sp_head.cc
@@ -2303,9 +2303,7 @@ sp_head::backpatch_goto(THD *thd, sp_label *lab,sp_label *lab_begin_block)
       */
       continue;
     }
-    if (my_strcasecmp(system_charset_info,
-                      bp->lab->name.str,
-                      lab->name.str) == 0)
+    if (lex_string_cmp(system_charset_info, &bp->lab->name, &lab->name) == 0)
     {
       if (bp->instr_type == GOTO)
       {
diff --git a/sql/sp_pcontext.cc b/sql/sp_pcontext.cc
index 87dfed2a8d3..1e2081e3479 100644
--- a/sql/sp_pcontext.cc
+++ b/sql/sp_pcontext.cc
@@ -132,8 +132,8 @@ sp_pcontext *sp_pcontext::push_context(THD *thd, sp_pcontext::enum_scope scope)
 
 bool cmp_labels(sp_label *a, sp_label *b)
 {
-  return (my_strcasecmp(system_charset_info, a->name.str, b->name.str) == 0
-          && a->type == b->type);
+  return (lex_string_cmp(system_charset_info, &a->name, &b->name) == 0 &&
+          a->type == b->type);
 }
 
 sp_pcontext *sp_pcontext::pop_context()
@@ -304,7 +304,7 @@ sp_label *sp_pcontext::find_goto_label(const LEX_CSTRING *name, bool recusive)
 
   while ((lab= li++))
   {
-    if (my_strcasecmp(system_charset_info, name->str, lab->name.str) == 0)
+    if (lex_string_cmp(system_charset_info, name, &lab->name) == 0)
       return lab;
   }
 
@@ -341,7 +341,7 @@ sp_label *sp_pcontext::find_label(const LEX_CSTRING *name)
 
   while ((lab= li++))
   {
-    if (my_strcasecmp(system_charset_info, name->str, lab->name.str) == 0)
+    if (lex_string_cmp(system_charset_info, name, &lab->name) == 0)
       return lab;
   }
 
diff --git a/sql/sql_acl.cc b/sql/sql_acl.cc
index 81859d2fed6..193a51efbc1 100644
--- a/sql/sql_acl.cc
+++ b/sql/sql_acl.cc
@@ -1594,12 +1594,10 @@ static const char *fix_plugin_ptr(const char *name)
 */
 static bool fix_user_plugin_ptr(ACL_USER *user)
 {
-  if (my_strcasecmp(system_charset_info, user->plugin.str,
-                    native_password_plugin_name.str) == 0)
+  if (lex_string_eq(&user->plugin, &native_password_plugin_name) == 0)
     user->plugin= native_password_plugin_name;
   else
-  if (my_strcasecmp(system_charset_info, user->plugin.str,
-                    old_password_plugin_name.str) == 0)
+  if (lex_string_eq(&user->plugin, &old_password_plugin_name) == 0)
     user->plugin= old_password_plugin_name;
   else
     return true;
@@ -1639,12 +1637,10 @@ static bool fix_lex_user(THD *thd, LEX_USER *user)
   DBUG_ASSERT(user->plugin.length || !user->auth.length);
   DBUG_ASSERT(!(user->plugin.length && (user->pwtext.length || user->pwhash.length)));
 
-  if (my_strcasecmp(system_charset_info, user->plugin.str,
-                    native_password_plugin_name.str) == 0)
+  if (lex_string_eq(&user->plugin, &native_password_plugin_name) == 0)
     check_length= SCRAMBLED_PASSWORD_CHAR_LENGTH;
   else
-  if (my_strcasecmp(system_charset_info, user->plugin.str,
-                    old_password_plugin_name.str) == 0)
+  if (lex_string_eq(&user->plugin, &old_password_plugin_name) == 0)
     check_length= SCRAMBLED_PASSWORD_CHAR_LENGTH_323;
   else
   if (user->plugin.length)
@@ -11200,7 +11196,7 @@ applicable_roles_insert(ACL_USER_BASE *grantee, ACL_ROLE *role, void *ptr)
   if (!is_role)
   {
     if (data->user->default_rolename.length &&
-        !strcmp(data->user->default_rolename.str, role->user.str))
+        !lex_string_eq(&data->user->default_rolename, &role->user))
       table->field[3]->store(STRING_WITH_LEN("YES"), cs);
     else
       table->field[3]->store(STRING_WITH_LEN("NO"), cs);
@@ -12769,8 +12765,8 @@ static ulong parse_client_handshake_packet(MPVIO_EXT *mpvio,
     restarted and a server auth plugin will read the data that the client
     has just send. Cache them to return in the next server_mpvio_read_packet().
   */
-  if (my_strcasecmp(system_charset_info, mpvio->acl_user->plugin.str,
-                    plugin_name(mpvio->plugin)->str) != 0)
+  if (lex_string_eq(&mpvio->acl_user->plugin,
+                    plugin_name(mpvio->plugin)) != 0)
   {
     mpvio->cached_client_reply.pkt= passwd;
     mpvio->cached_client_reply.pkt_len= passwd_len;
@@ -13200,8 +13196,7 @@ bool acl_authenticate(THD *thd, uint com_change_user_pkt_len)
   {
     DBUG_ASSERT(mpvio.acl_user);
     DBUG_ASSERT(command == COM_CHANGE_USER ||
-                my_strcasecmp(system_charset_info, auth_plugin_name->str,
-                              mpvio.acl_user->plugin.str));
+                lex_string_eq(auth_plugin_name, &mpvio.acl_user->plugin));
     auth_plugin_name= &mpvio.acl_user->plugin;
     res= do_auth_once(thd, auth_plugin_name, &mpvio);
   }
diff --git a/sql/sql_base.cc b/sql/sql_base.cc
index 9d295f713ce..f3710c48192 100644
--- a/sql/sql_base.cc
+++ b/sql/sql_base.cc
@@ -1136,10 +1136,10 @@ void update_non_unique_table_error(TABLE_LIST *update,
       update->view == duplicate->view ||
       update->view_name.length != duplicate->view_name.length ||
       update->view_db.length != duplicate->view_db.length ||
-      my_strcasecmp(table_alias_charset,
-                    update->view_name.str, duplicate->view_name.str) != 0 ||
-      my_strcasecmp(table_alias_charset,
-                    update->view_db.str, duplicate->view_db.str) != 0)
+      lex_string_cmp(table_alias_charset,
+                     &update->view_name, &duplicate->view_name) != 0 ||
+      lex_string_cmp(table_alias_charset,
+                     &update->view_db, &duplicate->view_db) != 0)
   {
     /*
       it is not the same view repeated (but it can be parts of the same copy
@@ -6107,8 +6107,8 @@ find_item_in_list(Item *find, List<Item> &items, uint *counter,
 	  item is not fix_field()'ed yet.
         */
         if (item_field->field_name.str && item_field->table_name &&
-	    !my_strcasecmp(system_charset_info, item_field->field_name.str,
-                           field_name->str) &&
+	    !lex_string_cmp(system_charset_info, &item_field->field_name,
+                            field_name) &&
             !my_strcasecmp(table_alias_charset, item_field->table_name, 
                            table_name) &&
             (!db_name || (item_field->db_name &&
@@ -6137,11 +6137,11 @@ find_item_in_list(Item *find, List<Item> &items, uint *counter,
       }
       else
       {
-        int fname_cmp= my_strcasecmp(system_charset_info,
-                                     item_field->field_name.str,
-                                     field_name->str);
-        if (!my_strcasecmp(system_charset_info,
-                           item_field->name.str,field_name->str))
+        bool fname_cmp= lex_string_cmp(system_charset_info,
+                                       &item_field->field_name,
+                                       field_name);
+        if (!lex_string_cmp(system_charset_info,
+                            &item_field->name, field_name))
         {
           /*
             If table name was not given we should scan through aliases
@@ -6187,7 +6187,7 @@ find_item_in_list(Item *find, List<Item> &items, uint *counter,
     { 
       if (is_ref_by_name && find->name.str && item->name.str &&
           find->name.length == item->name.length &&
-	  !my_strcasecmp(system_charset_info,item->name.str, find->name.str))
+	  !lex_string_cmp(system_charset_info, &item->name, &find->name))
       {
         found= li.ref();
         *counter= i;
@@ -6404,8 +6404,8 @@ mark_common_columns(THD *thd, TABLE_LIST *table_ref_1, TABLE_LIST *table_ref_2,
         here. These columns must be checked only on unqualified reference 
         by name (e.g. in SELECT list).
       */
-      if (!my_strcasecmp(system_charset_info, field_name_1->str,
-                         cur_field_name_2->str))
+      if (!lex_string_cmp(system_charset_info, field_name_1,
+                          cur_field_name_2))
       {
         DBUG_PRINT ("info", ("match c1.is_common=%d", nj_col_1->is_common));
         if (cur_nj_col_2->is_common ||
diff --git a/sql/sql_class.cc b/sql/sql_class.cc
index 1e18326ec20..21aa24e0d15 100644
--- a/sql/sql_class.cc
+++ b/sql/sql_class.cc
@@ -121,8 +121,8 @@ extern "C" void free_sequence_last(SEQUENCE_LAST_VALUE *entry)
 bool Key_part_spec::operator==(const Key_part_spec& other) const
 {
   return length == other.length &&
-         !my_strcasecmp(system_charset_info, field_name.str,
-                        other.field_name.str);
+         !lex_string_cmp(system_charset_info, &field_name,
+                         &other.field_name);
 }
 
 /**
@@ -249,9 +249,9 @@ bool Foreign_key::validate(List<Create_field> &table_fields)
   {
     it.rewind();
     while ((sql_field= it++) &&
-           my_strcasecmp(system_charset_info,
-                         column->field_name.str,
-                         sql_field->field_name.str)) {}
+           lex_string_cmp(system_charset_info,
+                          &column->field_name,
+                          &sql_field->field_name)) {}
     if (!sql_field)
     {
       my_error(ER_KEY_COLUMN_DOES_NOT_EXITS, MYF(0), column->field_name.str);
diff --git a/sql/sql_class.h b/sql/sql_class.h
index 46bd2f6a2b7..74857a94471 100644
--- a/sql/sql_class.h
+++ b/sql/sql_class.h
@@ -6118,6 +6118,25 @@ public:
   }
 };
 
+/* Functions to compare if two lex strings are equal */
+inline bool lex_string_cmp(CHARSET_INFO *charset,
+                           const LEX_CSTRING *a,
+                           const LEX_CSTRING *b)
+{
+  return my_strcasecmp(charset, a->str, b->str);
+}
+
+/*
+  Compare if two LEX_CSTRING are equal. Assumption is that
+  character set is ASCII (like for plugin names)
+*/
+inline bool lex_string_eq(const LEX_CSTRING *a,
+                          const LEX_CSTRING *b)
+{
+  if (a->length != b->length)
+    return 1;                                   /* Different */
+  return strcasecmp(a->str, b->str) != 0;
+}
 
 #endif /* MYSQL_SERVER */
 
diff --git a/sql/sql_cte.cc b/sql/sql_cte.cc
index 8045eb7eb63..2047c7c8762 100644
--- a/sql/sql_cte.cc
+++ b/sql/sql_cte.cc
@@ -129,8 +129,8 @@ bool With_clause::check_dependencies()
          elem != with_elem;
          elem= elem->next)
     {
-      if (my_strcasecmp(system_charset_info, with_elem->query_name->str,
-                        elem->query_name->str) == 0)
+      if (lex_string_cmp(system_charset_info, with_elem->query_name,
+                         elem->query_name) == 0)
       {
 	my_error(ER_DUP_QUERY_NAME, MYF(0), with_elem->query_name->str);
 	return true;
diff --git a/sql/sql_lex.cc b/sql/sql_lex.cc
index c71c1e6f378..e06a35003bd 100644
--- a/sql/sql_lex.cc
+++ b/sql/sql_lex.cc
@@ -5793,8 +5793,8 @@ bool LEX::sp_block_finalize(THD *thd, const Lex_spblock_st spblock,
   if (sp_block_finalize(thd, spblock, &splabel))
     return true;
   if (end_label->str &&
-      my_strcasecmp(system_charset_info,
-                    end_label->str, splabel->name.str) != 0)
+      lex_string_cmp(system_charset_info,
+                     end_label, &splabel->name) != 0)
   {
     my_error(ER_SP_LABEL_MISMATCH, MYF(0), end_label->str);
     return true;
@@ -6201,8 +6201,8 @@ bool LEX::sp_pop_loop_label(THD *thd, const LEX_CSTRING *label_name)
   sp_label *lab= spcont->pop_label();
   sphead->backpatch(lab);
   if (label_name->str &&
-      my_strcasecmp(system_charset_info, label_name->str,
-                                         lab->name.str) != 0)
+      lex_string_cmp(system_charset_info, label_name,
+                     &lab->name) != 0)
   {
     my_error(ER_SP_LABEL_MISMATCH, MYF(0), label_name->str);
     return true;
diff --git a/sql/sql_table.cc b/sql/sql_table.cc
index 7ed4d5d3fa4..dd04fdafa74 100644
--- a/sql/sql_table.cc
+++ b/sql/sql_table.cc
@@ -3055,30 +3055,25 @@ static void check_duplicate_key(THD *thd, Key *key, KEY *key_info,
     */
 
     List_iterator_fast<Key_part_spec> k_column_iterator(k->columns);
-
-    bool all_columns_are_identical= true;
-
+    uint i;
     key_column_iterator.rewind();
 
-    for (uint i= 0; i < key->columns.elements; ++i)
+    for (i= 0; i < key->columns.elements; ++i)
     {
       Key_part_spec *c1= key_column_iterator++;
       Key_part_spec *c2= k_column_iterator++;
 
       DBUG_ASSERT(c1 && c2);
 
-      if (my_strcasecmp(system_charset_info,
-                        c1->field_name.str, c2->field_name.str) ||
+      if (lex_string_cmp(system_charset_info,
+                         &c1->field_name, &c2->field_name) ||
           (c1->length != c2->length))
-      {
-        all_columns_are_identical= false;
         break;
-      }
     }
 
     // Report a warning if we have two identical keys.
 
-    if (all_columns_are_identical)
+    if (i == key->columns.elements)
     {
       push_warning_printf(thd, Sql_condition::WARN_LEVEL_NOTE,
                           ER_DUP_INDEX, ER_THD(thd, ER_DUP_INDEX),
@@ -3343,9 +3338,9 @@ mysql_prepare_create_table(THD *thd, HA_CREATE_INFO *create_info,
     /* Check if we have used the same field name before */
     for (dup_no=0; (dup_field=it2++) != sql_field; dup_no++)
     {
-      if (my_strcasecmp(system_charset_info,
-			sql_field->field_name.str,
-			dup_field->field_name.str) == 0)
+      if (lex_string_cmp(system_charset_info,
+                         &sql_field->field_name,
+                         &dup_field->field_name) == 0)
       {
 	/*
 	  If this was a CREATE ... SELECT statement, accept a field
@@ -3677,9 +3672,9 @@ mysql_prepare_create_table(THD *thd, HA_CREATE_INFO *create_info,
       it.rewind();
       field=0;
       while ((sql_field=it++) &&
-	     my_strcasecmp(system_charset_info,
-			   column->field_name.str,
-			   sql_field->field_name.str))
+	     lex_string_cmp(system_charset_info,
+                            &column->field_name,
+                            &sql_field->field_name))
 	field++;
       if (!sql_field)
       {
@@ -3688,8 +3683,8 @@ mysql_prepare_create_table(THD *thd, HA_CREATE_INFO *create_info,
       }
       while ((dup_column= cols2++) != column)
       {
-        if (!my_strcasecmp(system_charset_info,
-	     	           column->field_name.str, dup_column->field_name.str))
+        if (!lex_string_cmp(system_charset_info,
+                            &column->field_name, &dup_column->field_name))
 	{
 	  my_error(ER_DUP_FIELDNAME, MYF(0), column->field_name.str);
 	  DBUG_RETURN(TRUE);
@@ -4056,9 +4051,8 @@ mysql_prepare_create_table(THD *thd, HA_CREATE_INFO *create_info,
         Virtual_column_info *dup_check;
         while ((dup_check= dup_it++) && dup_check != check)
         {
-          if (check->name.length == dup_check->name.length &&
-              my_strcasecmp(system_charset_info,
-                            check->name.str, dup_check->name.str) == 0)
+          if (!lex_string_cmp(system_charset_info,
+                              &check->name, &dup_check->name))
           {
             my_error(ER_DUP_CONSTRAINT_NAME, MYF(0), "CHECK", check->name.str);
             DBUG_RETURN(TRUE);
@@ -5655,8 +5649,9 @@ handle_if_exists_options(THD *thd, TABLE *table, Alter_info *alter_info)
       */
       for (f_ptr=table->field; *f_ptr; f_ptr++)
       {
-        if (my_strcasecmp(system_charset_info,
-              sql_field->field_name.str, (*f_ptr)->field_name.str) == 0)
+        if (lex_string_cmp(system_charset_info,
+                           &sql_field->field_name,
+                           &(*f_ptr)->field_name) == 0)
           goto drop_create_field;
       }
       {
@@ -5668,8 +5663,9 @@ handle_if_exists_options(THD *thd, TABLE *table, Alter_info *alter_info)
         Create_field *chk_field;
         while ((chk_field= chk_it++) && chk_field != sql_field)
         {
-          if (my_strcasecmp(system_charset_info,
-                sql_field->field_name.str, chk_field->field_name.str) == 0)
+          if (lex_string_cmp(system_charset_info,
+                             &sql_field->field_name,
+                             &chk_field->field_name) == 0)
             goto drop_create_field;
         }
       }
@@ -5704,8 +5700,9 @@ drop_create_field:
       */
       for (f_ptr=table->field; *f_ptr; f_ptr++)
       {
-        if (my_strcasecmp(system_charset_info,
-              sql_field->change.str, (*f_ptr)->field_name.str) == 0)
+        if (lex_string_cmp(system_charset_info,
+                           &sql_field->change,
+                           &(*f_ptr)->field_name) == 0)
         {
           break;
         }
@@ -6024,8 +6021,8 @@ remove_key:
       {
         Virtual_column_info *dup= table->check_constraints[c];
         if (dup->name.length == check->name.length &&
-            my_strcasecmp(system_charset_info,
-                          check->name.str, dup->name.str) == 0)
+            lex_string_cmp(system_charset_info,
+                           &check->name, &dup->name) == 0)
         {
           push_warning_printf(thd, Sql_condition::WARN_LEVEL_NOTE,
             ER_DUP_CONSTRAINT_NAME, ER_THD(thd, ER_DUP_CONSTRAINT_NAME),
@@ -6332,8 +6329,8 @@ static bool fill_alter_inplace_info(THD *thd,
       }
 
       /* Check if field was renamed */
-      if (my_strcasecmp(system_charset_info, field->field_name.str,
-                        new_field->field_name.str))
+      if (lex_string_cmp(system_charset_info, &field->field_name,
+                         &new_field->field_name))
       {
         field->flags|= FIELD_IS_RENAMED;
         ha_alter_info->handler_flags|= Alter_inplace_info::ALTER_COLUMN_NAME;
@@ -6464,7 +6461,8 @@ static bool fill_alter_inplace_info(THD *thd,
          new_key < new_key_end;
          new_key++)
     {
-      if (! strcmp(table_key->name.str, new_key->name.str))
+      if (!lex_string_cmp(system_charset_info, &table_key->name,
+                          &new_key->name))
         break;
     }
     if (new_key >= new_key_end)
@@ -6555,7 +6553,8 @@ static bool fill_alter_inplace_info(THD *thd,
     /* Search an old key with the same name. */
     for (table_key= table->key_info; table_key < table_key_end; table_key++)
     {
-      if (! strcmp(table_key->name.str, new_key->name.str))
+      if (!lex_string_cmp(system_charset_info, &table_key->name,
+                          &new_key->name))
         break;
     }
     if (table_key >= table_key_end)
@@ -6789,9 +6788,9 @@ bool mysql_compare_tables(TABLE *table,
       create_info->table_options|= HA_OPTION_PACK_RECORD;
 
     /* Check if field was renamed */
-    if (my_strcasecmp(system_charset_info,
-		      field->field_name.str,
-		      tmp_new_field->field_name.str))
+    if (lex_string_cmp(system_charset_info,
+                       &field->field_name,
+                       &tmp_new_field->field_name))
       DBUG_RETURN(false);
 
     /* Evaluate changes bitmap and send to check_if_incompatible_data() */
@@ -6818,7 +6817,8 @@ bool mysql_compare_tables(TABLE *table,
     /* Search a key with the same name. */
     for (new_key= key_info_buffer; new_key < new_key_end; new_key++)
     {
-      if (! strcmp(table_key->name.str, new_key->name.str))
+      if (!lex_string_cmp(system_charset_info, &table_key->name,
+                          &new_key->name))
         break;
     }
     if (new_key >= new_key_end)
@@ -6857,7 +6857,8 @@ bool mysql_compare_tables(TABLE *table,
     /* Search a key with the same name. */
     for (table_key= table->key_info; table_key < table_key_end; table_key++)
     {
-      if (! strcmp(table_key->name.str, new_key->name.str))
+      if (!lex_string_cmp(system_charset_info, &table_key->name,
+                          &new_key->name))
         break;
     }
     if (table_key >= table_key_end)
@@ -7505,8 +7506,8 @@ mysql_prepare_alter_table(THD *thd, TABLE *table,
     while ((def=def_it++))
     {
       if (def->change.str &&
-	  !my_strcasecmp(system_charset_info,field->field_name.str,
-                         def->change.str))
+	  !lex_string_cmp(system_charset_info, &field->field_name,
+                          &def->change))
 	break;
     }
     if (def)
@@ -7623,8 +7624,8 @@ mysql_prepare_alter_table(THD *thd, TABLE *table,
         find_it.rewind();
         while ((find=find_it++))
         {
-          if (!my_strcasecmp(system_charset_info, def->after.str,
-                             find->field_name.str))
+          if (!lex_string_cmp(system_charset_info, &def->after,
+                              &find->field_name))
             break;
         }
         if (!find)
@@ -7990,8 +7991,8 @@ fk_check_column_changes(THD *thd, Alter_info *alter_info,
     {
       Field *old_field= new_field->field;
 
-      if (my_strcasecmp(system_charset_info, old_field->field_name.str,
-                        new_field->field_name.str))
+      if (lex_string_cmp(system_charset_info, &old_field->field_name,
+                         &new_field->field_name))
       {
         /*
           Copy algorithm doesn't support proper renaming of columns in
@@ -8104,10 +8105,10 @@ static bool fk_prepare_copy_alter_table(THD *thd, TABLE *table,
       if ((drop->type == Alter_drop::FOREIGN_KEY) &&
           (my_strcasecmp(system_charset_info, f_key->foreign_id->str,
                          drop->name) == 0) &&
-          (my_strcasecmp(table_alias_charset, f_key->foreign_db->str,
-                         table->s->db.str) == 0) &&
-          (my_strcasecmp(table_alias_charset, f_key->foreign_table->str,
-                         table->s->table_name.str) == 0))
+          (lex_string_cmp(table_alias_charset, f_key->foreign_db,
+                          &table->s->db) == 0) &&
+          (lex_string_cmp(table_alias_charset, f_key->foreign_table,
+                          &table->s->table_name) == 0))
         fk_parent_key_it.remove();
     }
   }
diff --git a/sql/sql_trigger.cc b/sql/sql_trigger.cc
index 7e3f047ef91..dcce8ae3724 100644
--- a/sql/sql_trigger.cc
+++ b/sql/sql_trigger.cc
@@ -750,8 +750,8 @@ bool Table_triggers_list::create_trigger(THD *thd, TABLE_LIST *tables,
     DBUG_RETURN(true);
 
   /* Trigger must be in the same schema as target table. */
-  if (my_strcasecmp(table_alias_charset, table->s->db.str,
-                    lex->spname->m_db.str))
+  if (lex_string_cmp(table_alias_charset, &table->s->db,
+                     &lex->spname->m_db))
   {
     my_error(ER_TRG_IN_WRONG_SCHEMA, MYF(0));
     DBUG_RETURN(true);
@@ -1084,8 +1084,8 @@ Trigger *Table_triggers_list::find_trigger(const LEX_CSTRING *name,
            (trigger= *parent);
            parent= &trigger->next)
       {
-        if (my_strcasecmp(table_alias_charset,
-                          trigger->name.str, name->str) == 0)
+        if (lex_string_cmp(table_alias_charset,
+                           &trigger->name, name) == 0)
         {
           if (remove_from_list)
           {
@@ -1633,8 +1633,8 @@ void Table_triggers_list::add_trigger(trg_event_type event,
   for ( ; *parent ; parent= &(*parent)->next, position++)
   {
     if (ordering_clause != TRG_ORDER_NONE &&
-        !my_strcasecmp(table_alias_charset, anchor_trigger_name->str,
-                       (*parent)->name.str))
+        !lex_string_cmp(table_alias_charset, anchor_trigger_name,
+                        &(*parent)->name))
     {
       if (ordering_clause == TRG_ORDER_FOLLOWS)
       {
diff --git a/sql/sql_truncate.cc b/sql/sql_truncate.cc
index 13b553f8b71..1d6edbc5fc9 100644
--- a/sql/sql_truncate.cc
+++ b/sql/sql_truncate.cc
@@ -151,18 +151,18 @@ fk_truncate_illegal_if_parent(THD *thd, TABLE *table)
   /* Loop over the set of foreign keys for which this table is a parent. */
   while ((fk_info= it++))
   {
-    DBUG_ASSERT(!my_strcasecmp(system_charset_info,
-                               fk_info->referenced_db->str,
-                               table->s->db.str));
-
-    DBUG_ASSERT(!my_strcasecmp(system_charset_info,
-                               fk_info->referenced_table->str,
-                               table->s->table_name.str));
-
-    if (my_strcasecmp(system_charset_info, fk_info->foreign_db->str,
-                      table->s->db.str) ||
-        my_strcasecmp(system_charset_info, fk_info->foreign_table->str,
-                      table->s->table_name.str))
+    DBUG_ASSERT(!lex_string_cmp(system_charset_info,
+                                fk_info->referenced_db,
+                                &table->s->db));
+
+    DBUG_ASSERT(!lex_string_cmp(system_charset_info,
+                                fk_info->referenced_table,
+                                &table->s->table_name));
+
+    if (lex_string_cmp(system_charset_info, fk_info->foreign_db,
+                       &table->s->db) ||
+        lex_string_cmp(system_charset_info, fk_info->foreign_table,
+                       &table->s->table_name))
       break;
   }
 
diff --git a/sql/sql_view.cc b/sql/sql_view.cc
index 0547a3cb343..26941e9d6e7 100644
--- a/sql/sql_view.cc
+++ b/sql/sql_view.cc
@@ -140,7 +140,7 @@ bool check_duplicate_names(THD *thd, List<Item> &item_list, bool gen_unique_view
     itc.rewind();
     while ((check= itc++) && check != item)
     {
-      if (my_strcasecmp(system_charset_info, item->name.str, check->name.str) == 0)
+      if (lex_string_cmp(system_charset_info, &item->name, &check->name) == 0)
       {
         if (!gen_unique_view_name)
           goto err;
diff --git a/sql/table.cc b/sql/table.cc
index 5182bbbb1d6..142d0a76997 100644
--- a/sql/table.cc
+++ b/sql/table.cc
@@ -251,30 +251,18 @@ TABLE_CATEGORY get_table_category(const LEX_CSTRING *db,
   if (is_infoschema_db(db->str, db->length))
     return TABLE_CATEGORY_INFORMATION;
 
-  if ((db->length == PERFORMANCE_SCHEMA_DB_NAME.length) &&
-      (my_strcasecmp(system_charset_info,
-                     PERFORMANCE_SCHEMA_DB_NAME.str,
-                     db->str) == 0))
+  if (lex_string_eq(&PERFORMANCE_SCHEMA_DB_NAME, db) == 0)
     return TABLE_CATEGORY_PERFORMANCE;
 
-  if ((db->length == MYSQL_SCHEMA_NAME.length) &&
-      (my_strcasecmp(system_charset_info,
-                     MYSQL_SCHEMA_NAME.str,
-                     db->str) == 0))
+  if (lex_string_eq(&MYSQL_SCHEMA_NAME, db) == 0)
   {
     if (is_system_table_name(name->str, name->length))
       return TABLE_CATEGORY_SYSTEM;
 
-    if ((name->length == GENERAL_LOG_NAME.length) &&
-        (my_strcasecmp(system_charset_info,
-                       GENERAL_LOG_NAME.str,
-                       name->str) == 0))
+    if (lex_string_eq(&GENERAL_LOG_NAME, name) == 0)
       return TABLE_CATEGORY_LOG;
 
-    if ((name->length == SLOW_LOG_NAME.length) &&
-        (my_strcasecmp(system_charset_info,
-                       SLOW_LOG_NAME.str,
-                       name->str) == 0))
+    if (lex_string_eq(&SLOW_LOG_NAME, name) == 0)
       return TABLE_CATEGORY_LOG;
   }
 
@@ -8299,7 +8287,7 @@ Field *TABLE::find_field_by_name(LEX_CSTRING *str) const
   for (Field **tmp= field; *tmp; tmp++)
   {
     if ((*tmp)->field_name.length == length &&
-        !my_strcasecmp(system_charset_info, (*tmp)->field_name.str, str->str))
+        !lex_string_cmp(system_charset_info, &(*tmp)->field_name, str))
       return *tmp;
   }
   return NULL;