Terminology: 'metadata' not 'default rec'

This follows up to commit 755187c8.

TRX_UNDO_INSERT_METADATA: Renamed from TRX_UNDO_INSERT_DEFAULT

trx_undo_metadata: Renamed from trx_undo_default_rec

storage/innobase/include/row0mysql.h

@@ -688,7 +688,7 @@ struct row_prebuilt_t {
 					to the Innobase format from the MySQL
 					format */
 	const byte*	default_rec;	/*!< the default values of all columns
-					(a "metadata") in MySQL format */
+					(a "default row") in MySQL format */
 	ulint		hint_need_to_fetch_extra_cols;
 					/*!< normally this is set to 0; if this
 					is set to ROW_RETRIEVE_PRIMARY_KEY,

storage/innobase/include/trx0rec.h

@@ -311,7 +311,7 @@ compilation info multiplied by 16 is ORed to this value in an undo log
 record */
 
 #define	TRX_UNDO_RENAME_TABLE	9	/*!< RENAME TABLE */
-#define	TRX_UNDO_INSERT_DEFAULT	10	/*!< insert a "default value"
+#define	TRX_UNDO_INSERT_METADATA 10	/*!< insert a metadata
 					pseudo-record for instant ALTER */
 #define	TRX_UNDO_INSERT_REC	11	/* fresh insert into clustered index */
 #define	TRX_UNDO_UPD_EXIST_REC	12	/* update of a non-delete-marked
@@ -328,8 +328,8 @@ record */
 					storage fields: used by purge to
 					free the external storage */
 
-/** The search tuple corresponding to TRX_UNDO_INSERT_DEFAULT */
-extern const dtuple_t trx_undo_default_rec;
+/** The search tuple corresponding to TRX_UNDO_INSERT_METADATA */
+extern const dtuple_t trx_undo_metadata;
 
 #include "trx0rec.ic"
 

storage/innobase/row/row0purge.cc

@@ -1043,7 +1043,7 @@ row_purge_parse_undo_rec(
 	switch (type) {
 	case TRX_UNDO_RENAME_TABLE:
 		return false;
-	case TRX_UNDO_INSERT_DEFAULT:
+	case TRX_UNDO_INSERT_METADATA:
 	case TRX_UNDO_INSERT_REC:
 		break;
 	default:
@@ -1080,7 +1080,7 @@ row_purge_parse_undo_rec(
 	}
 
 	switch (type) {
-	case TRX_UNDO_INSERT_DEFAULT:
+	case TRX_UNDO_INSERT_METADATA:
 	case TRX_UNDO_INSERT_REC:
 		break;
 	default:
@@ -1118,8 +1118,8 @@ row_purge_parse_undo_rec(
 		return(false);
 	}
 
-	if (type == TRX_UNDO_INSERT_DEFAULT) {
-		node->ref = &trx_undo_default_rec;
+	if (type == TRX_UNDO_INSERT_METADATA) {
+		node->ref = &trx_undo_metadata;
 		return(true);
 	}
 
@@ -1186,7 +1186,7 @@ row_purge_record_func(
 			MONITOR_INC(MONITOR_N_DEL_ROW_PURGE);
 		}
 		break;
-	case TRX_UNDO_INSERT_DEFAULT:
+	case TRX_UNDO_INSERT_METADATA:
 	case TRX_UNDO_INSERT_REC:
 		node->roll_ptr |= 1ULL << ROLL_PTR_INSERT_FLAG_POS;
 		/* fall through */

storage/innobase/row/row0uins.cc

@@ -227,7 +227,7 @@ row_undo_ins_remove_clust_rec(
 
 func_exit:
 	btr_pcur_commit_specify_mtr(&node->pcur, &mtr);
-	if (err == DB_SUCCESS && node->rec_type == TRX_UNDO_INSERT_DEFAULT) {
+	if (err == DB_SUCCESS && node->rec_type == TRX_UNDO_INSERT_METADATA) {
 		/* When rolling back the very first instant ADD COLUMN
 		operation, reset the root page to the basic state. */
 		ut_ad(!index->table->is_temporary());
@@ -422,7 +422,7 @@ row_undo_ins_parse_undo_rec(
 	default:
 		ut_ad(!"wrong undo record type");
 		goto close_table;
-	case TRX_UNDO_INSERT_DEFAULT:
+	case TRX_UNDO_INSERT_METADATA:
 	case TRX_UNDO_INSERT_REC:
 		break;
 	case TRX_UNDO_RENAME_TABLE:
@@ -464,7 +464,7 @@ row_undo_ins_parse_undo_rec(
 					ptr, clust_index, &node->ref,
 					node->heap);
 			} else {
-				node->ref = &trx_undo_default_rec;
+				node->ref = &trx_undo_metadata;
 			}
 
 			if (!row_undo_search_clust_to_pcur(node)) {
@@ -596,7 +596,7 @@ row_undo_ins(
 		}
 
 		/* fall through */
-	case TRX_UNDO_INSERT_DEFAULT:
+	case TRX_UNDO_INSERT_METADATA:
 		log_free_check();
 
 		if (node->table->id == DICT_INDEXES_ID) {

storage/innobase/row/row0undo.cc

@@ -236,7 +236,7 @@ row_undo_search_clust_to_pcur(
 					clust_index, node->update, node->heap);
 		} else {
 			ut_ad((node->row->info_bits == REC_INFO_MIN_REC_FLAG)
-			      == (node->rec_type == TRX_UNDO_INSERT_DEFAULT));
+			      == (node->rec_type == TRX_UNDO_INSERT_METADATA));
 			node->undo_row = NULL;
 			node->undo_ext = NULL;
 		}

storage/innobase/trx/trx0rec.cc

@@ -40,8 +40,8 @@ Created 3/26/1996 Heikki Tuuri
 #include "fsp0sysspace.h"
 #include "row0mysql.h"
 
-/** The search tuple corresponding to TRX_UNDO_INSERT_DEFAULT */
-const dtuple_t trx_undo_default_rec = {
+/** The search tuple corresponding to TRX_UNDO_INSERT_METADATA */
+const dtuple_t trx_undo_metadata = {
 	REC_INFO_METADATA, 0, 0,
 	NULL, 0, NULL,
 	UT_LIST_NODE_T(dtuple_t)()
@@ -510,7 +510,7 @@ trx_undo_page_report_insert(
 		ut_ad(index->is_instant());
 		ut_ad(undo_block->frame[first_free + 2]
 		      == TRX_UNDO_INSERT_REC);
-		undo_block->frame[first_free + 2] = TRX_UNDO_INSERT_DEFAULT;
+		undo_block->frame[first_free + 2] = TRX_UNDO_INSERT_METADATA;
 		goto done;
 	}
 

storage/innobase/trx/trx0roll.cc

@@ -1019,7 +1019,7 @@ trx_roll_pop_top_rec_of_trx(trx_t* trx, roll_ptr_t* roll_ptr, mem_heap_t* heap)
 	trx_undo_rec_t*	undo_rec = trx_roll_pop_top_rec(trx, undo, &mtr);
 	const undo_no_t	undo_no = trx_undo_rec_get_undo_no(undo_rec);
 	switch (trx_undo_rec_get_type(undo_rec)) {
-	case TRX_UNDO_INSERT_DEFAULT:
+	case TRX_UNDO_INSERT_METADATA:
 		/* This record type was introduced in MDEV-11369
 		instant ADD COLUMN, which was implemented after
 		MDEV-12288 removed the insert_undo log. There is no