remove HA_CREATE_INFO::frm_only - it's internal server flag,

not part of the SE API, and, again, mutually exclusive with
C_ORDINARY_CREATE and C_CREATE_SELECT.

sql/handler.h

@@ -1389,7 +1389,6 @@ struct HA_CREATE_INFO
   uint merge_insert_method;
   uint extra_size;                      /* length of extra data segment */
   enum ha_choice transactional;
-  bool frm_only;                        ///< 1 if no ha_create_table()
   bool varchar;                         ///< 1 if table has a VARCHAR
   enum ha_storage_media storage_media;  ///< DEFAULT, DISK or MEMORY
   enum ha_choice page_checksum;         ///< If we have page_checksums

sql/sql_table.cc

@@ -4090,7 +4090,7 @@ handler *mysql_create_frm_image(THD *thd,
   set_table_default_charset(thd, create_info, (char*) db);
 
   db_options= create_info->table_options;
-  if (!create_info->frm_only &&
+  if (create_table_mode != C_ALTER_TABLE_FRM_ONLY &&
       create_info->row_type != ROW_TYPE_FIXED &&
       create_info->row_type != ROW_TYPE_DEFAULT)
     db_options|= HA_OPTION_PACK_RECORD;
@@ -4324,7 +4324,8 @@ bool mysql_create_table_no_lock(THD *thd,
   handler	*file;
   LEX_CUSTRING  frm= {0,0};
   bool		error= TRUE;
-  bool          internal_tmp_table= create_table_mode == C_ALTER_TABLE;
+  bool          internal_tmp_table= create_table_mode == C_ALTER_TABLE ||
+                                    create_table_mode == C_ALTER_TABLE_FRM_ONLY;
   DBUG_ENTER("mysql_create_table_no_lock");
   DBUG_PRINT("enter", ("db: '%s'  table: '%s'  tmp: %d",
                        db, table_name, internal_tmp_table));
@@ -4385,7 +4386,8 @@ bool mysql_create_table_no_lock(THD *thd,
 
   thd_proc_info(thd, "creating table");
 
-  if (rea_create_table(thd, &frm, path, db, table_name, create_info, file))
+  if (rea_create_table(thd, &frm, path, db, table_name, create_info,
+                       create_table_mode == C_ALTER_TABLE_FRM_ONLY ? 0 : file))
     goto err;
 
   if (create_info->tmp_table())
@@ -4409,7 +4411,7 @@ bool mysql_create_table_no_lock(THD *thd,
     thd->thread_specific_used= TRUE;
   }
 #ifdef WITH_PARTITION_STORAGE_ENGINE
-  else if (thd->work_part_info && create_info->frm_only)
+  else if (thd->work_part_info && create_table_mode == C_ALTER_TABLE_FRM_ONLY)
   {
     /*
       For partitioned tables we can't find some problems with table
@@ -5944,7 +5946,7 @@ bool mysql_alter_table(THD *thd,char *new_db, char *new_name,
   TABLE *table, *new_table= 0;
   MDL_ticket *mdl_ticket;
   MDL_request target_mdl_request;
-  int error= 0;
+  int error= 0, create_table_mode= C_ALTER_TABLE;
   char tmp_name[80],old_name[32],new_name_buff[FN_REFLEN + 1];
   char new_alias_buff[FN_REFLEN], *table_name, *db, *new_alias, *alias;
   char index_file[FN_REFLEN], data_file[FN_REFLEN];
@@ -6615,10 +6617,11 @@ bool mysql_alter_table(THD *thd,char *new_db, char *new_name,
     char frm_name[FN_REFLEN+1];
     strxmov(frm_name, path, reg_ext, NullS);
     /*
-      frm_only can only be used if old frm exists.
+      C_ALTER_TABLE_FRM_ONLY can only be used if old frm exists.
       discovering frm-less engines cannot enjoy this optimization.
     */
-    create_info->frm_only= !my_access(frm_name, F_OK);
+    if (!my_access(frm_name, F_OK))
+      create_table_mode= C_ALTER_TABLE_FRM_ONLY;
   }
 
 #ifdef WITH_PARTITION_STORAGE_ENGINE
@@ -6688,13 +6691,13 @@ bool mysql_alter_table(THD *thd,char *new_db, char *new_name,
                   my_sleep(100000););
   /*
     Create a table with a temporary name.
-    With create_info->frm_only == 1 this creates a .frm file only and
+    With C_ALTER_TABLE_FRM_ONLY this creates a .frm file only and
     we keep the original row format.
     We don't log the statement, it will be logged later.
   */
   if (need_copy_table == ALTER_TABLE_METADATA_ONLY)
   {
-    DBUG_ASSERT(create_info->frm_only);
+    DBUG_ASSERT(create_table_mode == C_ALTER_TABLE_FRM_ONLY);
     /* Ensure we keep the original table format */
     create_info->table_options= ((create_info->table_options &
                                   ~HA_OPTION_PACK_RECORD) |
@@ -6703,7 +6706,7 @@ bool mysql_alter_table(THD *thd,char *new_db, char *new_name,
   }
   tmp_disable_binlog(thd);
   error= mysql_create_table_no_lock(thd, new_db, tmp_name, create_info,
-                                    alter_info, NULL, C_ALTER_TABLE);
+                                    alter_info, NULL, create_table_mode);
   reenable_binlog(thd);
   if (error)
     goto err;
@@ -7224,7 +7227,8 @@ err_new_table_cleanup:
   }
   else
     (void) quick_rm_table(new_db_type, new_db, tmp_name,
-                          create_info->frm_only ? FN_IS_TMP | FRM_ONLY : FN_IS_TMP);
+                          create_table_mode == C_ALTER_TABLE_FRM_ONLY ?
+                          FN_IS_TMP | FRM_ONLY : FN_IS_TMP);
 
 err:
 #ifdef WITH_PARTITION_STORAGE_ENGINE

sql/sql_table.h

@@ -156,6 +156,10 @@ bool mysql_create_table(THD *thd, TABLE_LIST *create_table,
   - ALTER TABLE, that creates a temporary table #sql-xxx, which will be later
     renamed to replace the original table.
 
+  - ALTER TABLE as above, but which only modifies the frm file, it only
+    creates an frm file for the #sql-xxx, the table in the engine is not
+    created.
+
   These situations are distinguished by the following "create table mode"
   values, where a CREATE ... SELECT is denoted by any non-negative number
   (which should be the number of fields in the SELECT ... part), and other
@@ -164,6 +168,7 @@ bool mysql_create_table(THD *thd, TABLE_LIST *create_table,
 #define C_CREATE_SELECT(X)        ((X) > 0 ? (X) : 0)
 #define C_ORDINARY_CREATE         0
 #define C_ALTER_TABLE            -1
+#define C_ALTER_TABLE_FRM_ONLY   -2
 
 bool mysql_create_table_no_lock(THD *thd, const char *db,
                                 const char *table_name,

sql/unireg.cc

@@ -361,7 +361,7 @@ err:
     db			Data base name
     table_name		Table name
     create_info		create info parameters
-    file		Handler to use or NULL if only frm needs to be created
+    file                Handler to use or NULL if only frm needs to be created
 
   RETURN
     0  ok
@@ -374,21 +374,16 @@ int rea_create_table(THD *thd, LEX_CUSTRING *frm,
 {
   DBUG_ENTER("rea_create_table");
 
-  if (thd->variables.keep_files_on_create)
-    create_info->options|= HA_CREATE_KEEP_FILES;
-
-  if (create_info->frm_only)
-  {
-    if (writefrm(path, db, table_name, 1, frm->str, frm->length))
-      goto err_handler;
-  }
-  else
+  if (file)
   {
     // TODO don't write frm for temp tables
     if (create_info->tmp_table() &&
         writefrm(path, db, table_name, 0, frm->str, frm->length))
       goto err_handler;
 
+    if (thd->variables.keep_files_on_create)
+      create_info->options|= HA_CREATE_KEEP_FILES;
+
     if (file->ha_create_partitioning_metadata(path, NULL, CHF_CREATE_FLAG,
                                               create_info) ||
        ha_create_table(thd, path, db, table_name, create_info, frm))
@@ -398,6 +393,11 @@ int rea_create_table(THD *thd, LEX_CUSTRING *frm,
       goto err_handler;
     }
   }
+  else
+  {
+    if (writefrm(path, db, table_name, 1, frm->str, frm->length))
+      goto err_handler;
+  }
 
   DBUG_RETURN(0);