A preparatory patch for MDEV-7284 INDEX: CREATE OR REPLACE.

Removing "bool Key::create_if_not_exists" and deriving Key from
DDL_options instead.

sql/sql_class.cc

@@ -112,13 +112,12 @@ bool Key_part_spec::operator==(const Key_part_spec& other) const
 */
 
 Key::Key(const Key &rhs, MEM_ROOT *mem_root)
-  :type(rhs.type),
+  :DDL_options(rhs),type(rhs.type),
   key_create_info(rhs.key_create_info),
   columns(rhs.columns, mem_root),
   name(rhs.name),
   option_list(rhs.option_list),
-  generated(rhs.generated),
-  create_if_not_exists(rhs.create_if_not_exists)
+  generated(rhs.generated)
 {
   list_copy_and_replace_each_value(columns, mem_root);
 }

sql/sql_class.h

@@ -278,7 +278,7 @@ public:
 };
 
 
-class Key :public Sql_alloc {
+class Key :public Sql_alloc, public DDL_options {
 public:
   enum Keytype { PRIMARY, UNIQUE, MULTIPLE, FULLTEXT, SPATIAL, FOREIGN_KEY};
   enum Keytype type;
@@ -287,31 +287,30 @@ public:
   LEX_STRING name;
   engine_option_value *option_list;
   bool generated;
-  bool create_if_not_exists;
 
   Key(enum Keytype type_par, const LEX_STRING &name_arg,
-      ha_key_alg algorithm_arg, bool generated_arg, bool if_not_exists_opt)
-    :type(type_par), key_create_info(default_key_create_info),
-    name(name_arg), option_list(NULL), generated(generated_arg),
-    create_if_not_exists(if_not_exists_opt)
+      ha_key_alg algorithm_arg, bool generated_arg, DDL_options_st ddl_options)
+    :DDL_options(ddl_options),
+     type(type_par), key_create_info(default_key_create_info),
+    name(name_arg), option_list(NULL), generated(generated_arg)
   {
     key_create_info.algorithm= algorithm_arg;
   } 
   Key(enum Keytype type_par, const LEX_STRING &name_arg,
       KEY_CREATE_INFO *key_info_arg,
       bool generated_arg, List<Key_part_spec> &cols,
-      engine_option_value *create_opt, bool if_not_exists_opt)
-    :type(type_par), key_create_info(*key_info_arg), columns(cols),
-    name(name_arg), option_list(create_opt), generated(generated_arg),
-    create_if_not_exists(if_not_exists_opt)
+      engine_option_value *create_opt, DDL_options_st ddl_options)
+    :DDL_options(ddl_options),
+     type(type_par), key_create_info(*key_info_arg), columns(cols),
+    name(name_arg), option_list(create_opt), generated(generated_arg)
   {}
   Key(enum Keytype type_par, const char *name_arg, size_t name_len_arg,
       KEY_CREATE_INFO *key_info_arg, bool generated_arg,
       List<Key_part_spec> &cols,
-      engine_option_value *create_opt, bool if_not_exists_opt)
-    :type(type_par), key_create_info(*key_info_arg), columns(cols),
-    option_list(create_opt), generated(generated_arg),
-    create_if_not_exists(if_not_exists_opt)
+      engine_option_value *create_opt, DDL_options_st ddl_options)
+    :DDL_options(ddl_options),
+    type(type_par), key_create_info(*key_info_arg), columns(cols),
+    option_list(create_opt), generated(generated_arg)
   {
     name.str= (char *)name_arg;
     name.length= name_len_arg;
@@ -344,9 +343,9 @@ public:
 	      const LEX_STRING &ref_db_arg, const LEX_STRING &ref_table_arg,
               List<Key_part_spec> &ref_cols,
 	      uint delete_opt_arg, uint update_opt_arg, uint match_opt_arg,
-              bool if_not_exists_opt)
+	      DDL_options ddl_options)
     :Key(FOREIGN_KEY, name_arg, &default_key_create_info, 0, cols, NULL,
-         if_not_exists_opt),
+         ddl_options),
     ref_db(ref_db_arg), ref_table(ref_table_arg), ref_columns(ref_cols),
     delete_opt(delete_opt_arg), update_opt(update_opt_arg),
     match_opt(match_opt_arg)

sql/sql_lex.h

@@ -2857,7 +2857,7 @@ public:
                ha_key_alg algorithm, DDL_options_st ddl)
   {
     if (check_add_key(ddl) ||
-        !(last_key= new Key(type, name, algorithm, false, ddl.if_not_exists())))
+        !(last_key= new Key(type, name, algorithm, false, ddl)))
       return true;
     alter_info.key_list.push_back(last_key);
     return false;
@@ -2866,7 +2866,7 @@ public:
   bool add_create_index(Key::Keytype type, const LEX_STRING &name,
                         ha_key_alg algorithm, DDL_options_st ddl)
   {
-    if (!(last_key= new Key(type, name, algorithm, false, ddl.if_not_exists())))
+    if (!(last_key= new Key(type, name, algorithm, false, ddl)))
       return true;
     alter_info.key_list.push_back(last_key);
     return false;

sql/sql_table.cc

@@ -5830,7 +5830,7 @@ drop_create_field:
     const char *keyname;
     while ((key=key_it++))
     {
-      if (!key->create_if_not_exists)
+      if (!key->if_not_exists())
         continue;
       /* If the name of the key is not specified,     */
       /* let us check the name of the first key part. */
@@ -7627,7 +7627,7 @@ mysql_prepare_alter_table(THD *thd, TABLE *table,
       key= new Key(key_type, key_name, strlen(key_name),
                    &key_create_info,
                    MY_TEST(key_info->flags & HA_GENERATED_KEY),
-                   key_parts, key_info->option_list, FALSE);
+                   key_parts, key_info->option_list, DDL_options());
       new_key_list.push_back(key);
     }
   }

sql/sql_yacc.yy

@@ -852,7 +852,9 @@ static void add_key_to_list(LEX *lex, LEX_STRING *field_name,
                             enum Key::Keytype type, bool check_exists)
 {
   Key *key;
-  key= new Key(type, null_lex_str, HA_KEY_ALG_UNDEF, false, check_exists);
+  key= new Key(type, null_lex_str, HA_KEY_ALG_UNDEF, false,
+               DDL_options(check_exists ? DDL_options::OPT_IF_NOT_EXISTS :
+                                          DDL_options::OPT_NONE));
   key->columns.push_back(new Key_part_spec(*field_name, 0));
   lex->alter_info.key_list.push_back(key);
 }
@@ -6055,8 +6057,7 @@ key_def:
           {
             if (Lex->check_add_key($4) ||
                !(Lex->last_key= new Key(Key::MULTIPLE, $1.str ? $1 : $5,
-                                        HA_KEY_ALG_UNDEF, true,
-                                        $4.if_not_exists())))
+                                        HA_KEY_ALG_UNDEF, true, $4)))
               MYSQL_YYABORT;
             Lex->option_list= NULL;
           }
@@ -6071,7 +6072,7 @@ key_def:
                                       lex->fk_delete_opt,
                                       lex->fk_update_opt,
                                       lex->fk_match_option,
-                                      $4.if_not_exists());
+                                      $4);
             if (key == NULL)
               MYSQL_YYABORT;
             /*

sql/structs.h

@@ -477,7 +477,7 @@ public:
   DDL options:
   - CREATE IF NOT EXISTS
   - DROP IF EXISTS
-  - CRESTE LIKE
+  - CREATE LIKE
   - REPLACE
 */
 struct DDL_options_st
@@ -544,6 +544,9 @@ class DDL_options: public DDL_options_st
 {
 public:
   DDL_options() { init(); }
+  DDL_options(Options options) { init(options); }
+  DDL_options(const DDL_options_st &options)
+  { DDL_options_st::operator=(options); }
 };