Cleanup: Remove btr_pcur_t::old_stored

The Boolean field btr_pcur_t::old_stored mostly duplicates old_rec.
Let us remove it.

storage/innobase/btr/btr0pcur.cc

@@ -63,7 +63,6 @@ btr_pcur_reset(
 	cursor->old_rec = NULL;
 	cursor->old_n_core_fields = 0;
 	cursor->old_n_fields = 0;
-	cursor->old_stored = false;
 
 	cursor->latch_mode = BTR_NO_LATCHES;
 	cursor->pos_state = BTR_PCUR_NOT_POSITIONED;
@@ -125,8 +124,6 @@ btr_pcur_store_position(
 		  && mtr->memo_contains_flagged(&index->lock, MTR_MEMO_X_LOCK
 						| MTR_MEMO_SX_LOCK)));
 
-	cursor->old_stored = true;
-
 	if (page_is_empty(block->page.frame)) {
 		/* It must be an empty index tree; NOTE that in this case
 		we do not store the modify_clock, but always do a search
@@ -301,7 +298,6 @@ btr_pcur_t::restore_position(ulint restore_latch_mode, mtr_t *mtr)
 	mem_heap_t*	heap;
 
 	ut_ad(mtr->is_active());
-	//ut_ad(cursor->old_stored);
 	ut_ad(pos_state == BTR_PCUR_WAS_POSITIONED
 	      || pos_state == BTR_PCUR_IS_POSITIONED);
 
@@ -450,7 +446,6 @@ btr_pcur_t::restore_position(ulint restore_latch_mode, mtr_t *mtr)
 			block_when_stored.store(btr_pcur_get_block(this));
 			modify_clock= buf_block_get_modify_clock(
 			    block_when_stored.block());
-			old_stored= true;
 
 			mem_heap_free(heap);
 
@@ -487,7 +482,7 @@ btr_pcur_move_to_next_page(
 	ut_ad(cursor->latch_mode != BTR_NO_LATCHES);
 	ut_ad(btr_pcur_is_after_last_on_page(cursor));
 
-	cursor->old_stored = false;
+	cursor->old_rec = nullptr;
 
 	const page_t* page = btr_pcur_get_page(cursor);
 	const uint32_t next_page_no = btr_page_get_next(page);
@@ -594,7 +589,7 @@ btr_pcur_move_backward_from_page(
 	}
 
 	cursor->latch_mode = latch_mode;
-	cursor->old_stored = false;
+	cursor->old_rec = nullptr;
 	return false;
 }
 
@@ -612,7 +607,7 @@ btr_pcur_move_to_prev(
 	ut_ad(cursor->pos_state == BTR_PCUR_IS_POSITIONED);
 	ut_ad(cursor->latch_mode != BTR_NO_LATCHES);
 
-	cursor->old_stored = false;
+	cursor->old_rec = nullptr;
 
 	if (btr_pcur_is_before_first_on_page(cursor)) {
 		return (!btr_pcur_is_before_first_in_tree(cursor)

storage/innobase/fts/fts0fts.cc

@@ -3347,7 +3347,6 @@ fts_add_doc_by_id(
 	is_id_cluster = (clust_index == fts_id_index);
 
 	mtr_start(&mtr);
-	btr_pcur_init(&pcur);
 
 	/* Search based on Doc ID. Here, we'll need to consider the case
 	when there is no primary index on Doc ID */

storage/innobase/ibuf/ibuf0ibuf.cc

@@ -2402,8 +2402,8 @@ ulint ibuf_contract()
 	/* Open a cursor to a randomly chosen leaf of the tree, at a random
 	position within the leaf */
 	pcur.pos_state = BTR_PCUR_IS_POSITIONED;
-	pcur.old_stored = false;
-	pcur.trx_if_known = NULL;
+	pcur.old_rec = nullptr;
+	pcur.trx_if_known = nullptr;
 	pcur.search_mode = PAGE_CUR_G;
 	pcur.latch_mode = BTR_SEARCH_LEAF;
 

storage/innobase/include/btr0pcur.h

@@ -381,8 +381,6 @@ struct btr_pcur_t{
 	we say then that the cursor is detached; it can be restored to
 	attached if the old position was stored in old_rec */
 	ulint		latch_mode;
-	/** true if old_rec is stored */
-	bool		old_stored;
 	/** if cursor position is stored, contains an initial segment of the
 	latest record cursor was positioned either on, before or after */
 	rec_t*		old_rec;
@@ -416,7 +414,7 @@ struct btr_pcur_t{
 
 	btr_pcur_t() :
 		btr_cur(), latch_mode(RW_NO_LATCH),
-		old_stored(false), old_rec(NULL),
+		old_rec(NULL),
 		old_n_fields(0), rel_pos(btr_pcur_pos_t(0)),
 		block_when_stored(),
 		modify_clock(0), pos_state(BTR_PCUR_NOT_POSITIONED),

storage/innobase/include/btr0pcur.inl

@@ -36,7 +36,6 @@ btr_pcur_get_rel_pos(
 {
 	ut_ad(cursor);
 	ut_ad(cursor->old_rec);
-	ut_ad(cursor->old_stored);
 	ut_ad(cursor->pos_state == BTR_PCUR_WAS_POSITIONED
 	      || cursor->pos_state == BTR_PCUR_IS_POSITIONED);
 
@@ -163,7 +162,7 @@ btr_pcur_move_to_next_on_page(
 	ut_ad(cursor->pos_state == BTR_PCUR_IS_POSITIONED);
 	ut_ad(cursor->latch_mode != BTR_NO_LATCHES);
 
-	cursor->old_stored = false;
+	cursor->old_rec = nullptr;
 	return page_cur_move_to_next(btr_pcur_get_page_cur(cursor));
 }
 
@@ -177,7 +176,7 @@ btr_pcur_move_to_prev_on_page(
 {
 	ut_ad(cursor->pos_state == BTR_PCUR_IS_POSITIONED);
 	ut_ad(cursor->latch_mode != BTR_NO_LATCHES);
-	cursor->old_stored = false;
+	cursor->old_rec = nullptr;
 
 	return page_cur_move_to_prev(btr_pcur_get_page_cur(cursor));
 }
@@ -196,7 +195,7 @@ btr_pcur_move_to_next_user_rec(
 {
 	ut_ad(cursor->pos_state == BTR_PCUR_IS_POSITIONED);
 	ut_ad(cursor->latch_mode != BTR_NO_LATCHES);
-	cursor->old_stored = false;
+	cursor->old_rec = nullptr;
 loop:
 	if (btr_pcur_is_after_last_on_page(cursor)) {
 		if (btr_pcur_is_after_last_in_tree(cursor)
@@ -230,7 +229,7 @@ btr_pcur_move_to_next(
   ut_ad(cursor->pos_state == BTR_PCUR_IS_POSITIONED);
   ut_ad(cursor->latch_mode != BTR_NO_LATCHES);
 
-  cursor->old_stored= false;
+  cursor->old_rec= nullptr;
 
   if (btr_pcur_is_after_last_on_page(cursor))
     return !btr_pcur_is_after_last_in_tree(cursor) &&
@@ -294,7 +293,6 @@ btr_pcur_init(
 /*==========*/
 	btr_pcur_t*	pcur)	/*!< in: persistent cursor */
 {
-	pcur->old_stored = false;
 	pcur->old_rec_buf = NULL;
 	pcur->old_rec = NULL;
 
@@ -363,7 +361,6 @@ dberr_t btr_pcur_open_with_no_init(dict_index_t *index, const dtuple_t *tuple,
   cursor->latch_mode= BTR_LATCH_MODE_WITHOUT_INTENTION(latch_mode);
   cursor->search_mode= mode;
   cursor->pos_state= BTR_PCUR_IS_POSITIONED;
-  cursor->old_stored= false;
   cursor->trx_if_known= nullptr;
 
   /* Search with the tree cursor */
@@ -402,7 +399,7 @@ btr_pcur_open_at_index_side(
 		btr_pcur_get_btr_cur(pcur), level, mtr);
 	pcur->pos_state = BTR_PCUR_IS_POSITIONED;
 
-	pcur->old_stored = false;
+	pcur->old_rec = nullptr;
 
 	pcur->trx_if_known = NULL;
 
@@ -425,25 +422,21 @@ btr_pcur_close(
 /*===========*/
 	btr_pcur_t*	cursor)	/*!< in: persistent cursor */
 {
-	ut_free(cursor->old_rec_buf);
+  ut_free(cursor->old_rec_buf);
 
-	if (cursor->btr_cur.rtr_info) {
-		rtr_clean_rtr_info(cursor->btr_cur.rtr_info, true);
-		cursor->btr_cur.rtr_info = NULL;
-	}
-
-	cursor->old_rec = NULL;
-	cursor->old_rec_buf = NULL;
-	cursor->btr_cur.page_cur.rec = NULL;
-	cursor->btr_cur.page_cur.block = NULL;
+  if (cursor->btr_cur.rtr_info)
+    rtr_clean_rtr_info(cursor->btr_cur.rtr_info, true);
 
-	cursor->old_rec = NULL;
-	cursor->old_stored = false;
+  cursor->btr_cur.rtr_info= nullptr;
+  cursor->old_rec = nullptr;
+  cursor->old_rec_buf = nullptr;
+  cursor->btr_cur.page_cur.rec = nullptr;
+  cursor->btr_cur.page_cur.block = nullptr;
 
-	cursor->latch_mode = BTR_NO_LATCHES;
-	cursor->pos_state = BTR_PCUR_NOT_POSITIONED;
+  cursor->latch_mode = BTR_NO_LATCHES;
+  cursor->pos_state = BTR_PCUR_NOT_POSITIONED;
 
-	cursor->trx_if_known = NULL;
+  cursor->trx_if_known = nullptr;
 }
 
 /*********************************************************//**
@@ -459,5 +452,5 @@ btr_pcur_move_before_first_on_page(
 	page_cur_set_before_first(btr_pcur_get_block(cursor),
 		btr_pcur_get_page_cur(cursor));
 
-	cursor->old_stored = false;
+	cursor->old_rec = nullptr;
 }

storage/innobase/row/row0import.cc

@@ -1571,7 +1571,7 @@ dberr_t IndexPurge::next() noexcept
 		return DB_CORRUPTION;
 	}
 	/* The following is based on btr_pcur_move_to_next_user_rec(). */
-	m_pcur.old_stored = false;
+	m_pcur.old_rec = nullptr;
 	ut_ad(m_pcur.latch_mode == BTR_MODIFY_LEAF);
 	do {
 		if (btr_pcur_is_after_last_on_page(&m_pcur)) {

storage/innobase/row/row0ins.cc

@@ -1138,6 +1138,7 @@ row_ins_foreign_check_on_constraint(
 
 		ref = row_build_row_ref(ROW_COPY_POINTERS, index, rec,
 					tmp_heap);
+		cascade->pcur->old_rec = nullptr;
 		err = btr_pcur_open_with_no_init(clust_index, ref,
 						 PAGE_CUR_LE, BTR_SEARCH_LEAF,
 						 cascade->pcur, mtr);

storage/innobase/row/row0purge.cc

@@ -1340,7 +1340,7 @@ purge_node_t::validate_pcur()
 		return(true);
 	}
 
-	if (!pcur.old_stored) {
+	if (!pcur.old_rec) {
 		return(true);
 	}
 

storage/innobase/row/row0sel.cc

@@ -1018,7 +1018,7 @@ row_sel_get_clust_rec(
 	row_build_row_ref_fast(plan->clust_ref, plan->clust_map, rec, offsets);
 
 	index = dict_table_get_first_index(plan->table);
-
+	plan->clust_pcur.old_rec = nullptr;
 	dberr_t err = btr_pcur_open_with_no_init(index, plan->clust_ref,
 						 PAGE_CUR_LE, BTR_SEARCH_LEAF,
 						 &plan->clust_pcur, mtr);
@@ -1411,6 +1411,8 @@ row_sel_open_pcur(
 		cond = UT_LIST_GET_NEXT(cond_list, cond);
 	}
 
+	plan->pcur.old_rec = nullptr;
+
 	dberr_t err;
 
 	if (plan->tuple) {
@@ -3371,6 +3373,7 @@ Row_sel_get_clust_rec_for_mysql::operator()(
 	rec_t*		old_vers;
 	trx_t*		trx;
 
+	prebuilt->clust_pcur->old_rec = nullptr;
 	*out_rec = NULL;
 	trx = thr_get_trx(thr);
 
@@ -3965,6 +3968,7 @@ row_sel_try_search_shortcut_for_mysql(
 	ut_ad(!index->table->is_temporary());
 	ut_ad(!prebuilt->templ_contains_blob);
 	ut_ad(trx->read_view.is_open());
+	pcur->old_rec = nullptr;
 
 	if (btr_pcur_open_with_no_init(index, search_tuple, PAGE_CUR_GE,
 				       BTR_SEARCH_LEAF, pcur, mtr)
@@ -4767,6 +4771,7 @@ row_search_mvcc(
 
 	} else if (dtuple_get_n_fields(search_tuple) > 0) {
 		pcur->btr_cur.thr = thr;
+		pcur->old_rec = nullptr;
 
 		if (dict_index_is_spatial(index)) {
 			if (!prebuilt->rtr_info) {
@@ -5020,7 +5025,7 @@ row_search_mvcc(
 
 			page_cur_set_after_last(btr_pcur_get_block(pcur),
 						btr_pcur_get_page_cur(pcur));
-			pcur->old_stored = false;
+			pcur->old_rec = nullptr;
 			goto next_rec;
 		}
 	}
@@ -5786,7 +5791,7 @@ row_search_mvcc(
 			/* This is based on btr_pcur_move_to_next() */
 			ut_ad(pcur->pos_state == BTR_PCUR_IS_POSITIONED);
 			ut_ad(pcur->latch_mode != BTR_NO_LATCHES);
-			pcur->old_stored = false;
+			pcur->old_rec = nullptr;
 			if (btr_pcur_is_after_last_on_page(pcur)) {
 				if (btr_pcur_is_after_last_in_tree(pcur)) {
 					goto not_moved;
@@ -6198,8 +6203,6 @@ dberr_t row_check_index(row_prebuilt_t *prebuilt, ulint *n_rows)
   *n_rows= 0;
   dict_index_t *const index= prebuilt->index;
 
-  prebuilt->fetch_direction= ROW_SEL_NEXT;
-
   if (!index->is_btree())
     return DB_CORRUPTION;