Correctly update the metadata record to generic format

btr_cur_optimistic_insert(): Avoid unnecessary computation of rec_size.

btr_cur_pessimistic_update(): Correctly check for generic ALTER TABLE
metadata record when update an instant ADD COLUMN record.

instant_metadata(): Invoke dict_table_t::serialise_columns()
at the earliest possibility. Previously this was only invoked
during insert in dtuple_convert_big_rec().

rec_get_converted_size_comp_prefix_low(): Assume that the metadata
field will be stored externally. In dtuple_convert_big_rec() during
the rec_get_converted_size() call, it would not be there yet.

mysql-test/suite/innodb_gis/r/alter_spatial_index.result

@@ -521,7 +521,7 @@ HEX(c8)
 
 ROLLBACK;
 ALTER TABLE tab add COLUMN c9 POINT NOT NULL AFTER c5, ALGORITHM = INPLACE, LOCK=NONE;
-ERROR 0A000: LOCK=NONE is not supported. Reason: Do not support online operation on table with GIS index. Try LOCK=SHARED
+ALTER TABLE tab DROP COLUMN c9, ALGORITHM=INSTANT;
 SHOW CREATE TABLE tab;
 Table	Create Table
 tab	CREATE TABLE `tab` (

mysql-test/suite/innodb_gis/t/alter_spatial_index.test

@@ -491,9 +491,8 @@ FROM tab LIMIT 1;
 SELECT HEX(c8) FROM tab;
 ROLLBACK;
 
-# not instant, not supported
---error ER_ALTER_OPERATION_NOT_SUPPORTED_REASON
 ALTER TABLE tab add COLUMN c9 POINT NOT NULL AFTER c5, ALGORITHM = INPLACE, LOCK=NONE;
+ALTER TABLE tab DROP COLUMN c9, ALGORITHM=INSTANT;
 
 SHOW CREATE TABLE tab;
 

storage/innobase/btr/btr0cur.cc

@@ -3345,13 +3345,17 @@ btr_cur_optimistic_insert(
 
 	leaf = page_is_leaf(page);
 
+	if (UNIV_UNLIKELY(entry->is_alter_metadata())) {
+		ut_ad(leaf);
+		goto convert_big_rec;
+	}
+
 	/* Calculate the record size when entry is converted to a record */
 	rec_size = rec_get_converted_size(index, entry, n_ext);
 
 	if (page_zip_rec_needs_ext(rec_size, page_is_comp(page),
-				   dtuple_get_n_fields(entry), page_size)
-	    || UNIV_UNLIKELY(entry->is_alter_metadata())) {
-
+				   dtuple_get_n_fields(entry), page_size)) {
+convert_big_rec:
 		/* The record is so big that we have to store some fields
 		externally on separate database pages */
 		big_rec_vec = dtuple_convert_big_rec(index, 0, entry, &n_ext);
@@ -4780,7 +4784,7 @@ btr_cur_pessimistic_update(
 		    page_is_comp(page),
 		    dict_index_get_n_fields(index),
 		    block->page.size)
-	    || UNIV_UNLIKELY(rec_is_alter_metadata(rec, *index))) {
+	    || UNIV_UNLIKELY(update->is_alter_metadata())) {
 
 		big_rec_vec = dtuple_convert_big_rec(index, update, new_entry, &n_ext);
 		if (UNIV_UNLIKELY(big_rec_vec == NULL)) {

storage/innobase/data/data0data.cc

@@ -640,7 +640,9 @@ dtuple_convert_big_rec(
 	if (entry->is_alter_metadata()) {
 		longest_i = index->n_uniq + DATA_ROLL_PTR;
 		dfield = dtuple_get_nth_field(entry, longest_i);
+#if 1 // FIXME: remove this
 		index->table->serialise_columns(heap, dfield);
+#endif
 		local_len = BTR_EXTERN_FIELD_REF_SIZE;
 		goto ext_write;
 	}

storage/innobase/handler/handler0alter.cc

@@ -4744,10 +4744,7 @@ static dtuple_t* instant_metadata(
 		dfield_t* dfield = dtuple_get_nth_field(entry, i);
 
 		if (i == index.first_user_field()) {
-			dfield_set_data(dfield,
-					mem_heap_zalloc(heap, FIELD_REF_SIZE),
-					FIELD_REF_SIZE);
-			dfield_set_ext(dfield);
+			index.table->serialise_columns(heap, dfield);
 			dfield->type.metadata_blob_init();
 			field--;
 			continue;
@@ -5031,9 +5028,8 @@ static bool innobase_instant_try(
 			upd_field_t* uf = upd_get_nth_field(update, 0);
 			uf->field_no = index->first_user_field();
 			uf->new_val = entry->fields[uf->field_no];
-			DBUG_ASSERT(dfield_is_ext(&uf->new_val));
-			DBUG_ASSERT(dfield_get_len(&uf->new_val)
-				    == BTR_EXTERN_FIELD_REF_SIZE);
+			DBUG_ASSERT(!dfield_is_ext(&uf->new_val));
+			DBUG_ASSERT(!dfield_is_null(&uf->new_val));
 		}
 
 		/* Add the default values for instantly added columns */

storage/innobase/rem/rem0rec.cc

@@ -1169,15 +1169,13 @@ rec_get_converted_size_comp_prefix_low(
 	const dfield_t* const end = dfield + n_fields;
 	/* read the lengths of fields 0..n */
 	for (ulint i = 0; dfield < end; i++, dfield++) {
-		ulint len = dfield_get_len(dfield);
-
 		if (mblob && i == index->first_user_field()) {
-			ut_ad(len == FIELD_REF_SIZE);
-			ut_ad(dfield_is_ext(dfield));
-			data_size += len;
-			len = dfield_get_len(++dfield);
+			data_size += FIELD_REF_SIZE;
+			++dfield;
 		}
 
+		ulint len = dfield_get_len(dfield);
+
 		const dict_field_t* field = dict_index_get_nth_field(index, i);
 #ifdef UNIV_DEBUG
 		if (dict_index_is_spatial(index)) {

storage/innobase/row/row0upd.cc

@@ -1350,8 +1350,7 @@ row_upd_index_replace_metadata(
 		dfield_t* dfield = dtuple_get_nth_field(entry, f);
 
 		if (f-- == first) {
-			ut_ad(dfield_is_ext(&uf->new_val));
-			ut_ad(dfield_get_len(&uf->new_val) == FIELD_REF_SIZE);
+			ut_ad(!dfield_is_ext(&uf->new_val));
 			ut_ad(!dfield_is_null(&uf->new_val));
 			ut_ad(dfield_is_ext(dfield));
 			ut_ad(dfield_get_len(dfield) == FIELD_REF_SIZE);

storage/innobase/trx/trx0rec.cc

@@ -1046,8 +1046,8 @@ trx_undo_page_report_modify(
 			ut_ad(!upd_fld_is_virtual_col(&update->fields[0]));
 			ut_ad(update->fields[0].field_no
 			      == index->first_user_field());
-			ut_ad(update->fields[0].new_val.ext);
-			ut_ad(update->fields[0].new_val.len == FIELD_REF_SIZE);
+			ut_ad(!dfield_is_ext(&update->fields[0].new_val));
+			ut_ad(!dfield_is_null(&update->fields[0].new_val));
 			/* The instant ADD COLUMN metadata record does not
 			contain the BLOB. Do not write anything for it. */
 			i = !rec_is_alter_metadata(rec, *index);