Cleanup: Use the alias BTR_PURGE_TREE for pessimistic delete

storage/innobase/ibuf/ibuf0ibuf.cc

@@ -4011,8 +4011,7 @@ bool ibuf_delete_rec(const page_id_t page_id, btr_pcur_t* pcur,
 	ibuf_mtr_start(mtr);
 	mysql_mutex_lock(&ibuf_mutex);
 
-	if (!ibuf_restore_pos(page_id, search_tuple,
-			      BTR_MODIFY_TREE | BTR_LATCH_FOR_DELETE,
+	if (!ibuf_restore_pos(page_id, search_tuple, BTR_PURGE_TREE,
 			      pcur, mtr)) {
 
 		mysql_mutex_unlock(&ibuf_mutex);

storage/innobase/row/row0import.cc

@@ -1598,8 +1598,7 @@ tree structure may be changed during a pessimistic delete. */
 inline dberr_t IndexPurge::purge_pessimistic_delete() noexcept
 {
   dberr_t err;
-  if (m_pcur.restore_position(BTR_MODIFY_TREE | BTR_LATCH_FOR_DELETE,
-                              &m_mtr) != btr_pcur_t::CORRUPTED)
+  if (m_pcur.restore_position(BTR_PURGE_TREE, &m_mtr) != btr_pcur_t::CORRUPTED)
   {
     ut_ad(rec_get_deleted_flag(btr_pcur_get_rec(&m_pcur),
                                m_index->table->not_redundant()));

storage/innobase/row/row0log.cc

@@ -1696,8 +1696,7 @@ row_log_table_apply_delete_low(
 		mtr->start();
 		index->set_modified(*mtr);
 		error = btr_pcur_open(index, entry, PAGE_CUR_LE,
-				      BTR_MODIFY_TREE | BTR_LATCH_FOR_DELETE,
-				      pcur, mtr);
+				      BTR_PURGE_TREE, pcur, mtr);
 		if (error) {
 			goto err_exit;
 		}
@@ -1780,8 +1779,7 @@ row_log_table_apply_delete(
 	mtr_start(&mtr);
 	index->set_modified(mtr);
 	dberr_t err = btr_pcur_open(index, old_pk, PAGE_CUR_LE,
-				    BTR_MODIFY_TREE | BTR_LATCH_FOR_DELETE,
-				    &pcur, &mtr);
+				    BTR_PURGE_TREE, &pcur, &mtr);
 	if (err != DB_SUCCESS) {
 		goto all_done;
 	}

storage/innobase/row/row0purge.cc

@@ -216,7 +216,7 @@ row_purge_remove_clust_if_poss_low(
 			btr_pcur_get_btr_cur(&node->pcur), 0, &mtr);
 	} else {
 		dberr_t	err;
-		ut_ad(mode == (BTR_MODIFY_TREE | BTR_LATCH_FOR_DELETE));
+		ut_ad(mode == BTR_PURGE_TREE);
 		btr_cur_pessimistic_delete(
 			&err, FALSE, btr_pcur_get_btr_cur(&node->pcur), 0,
 			false, &mtr);
@@ -257,8 +257,7 @@ row_purge_remove_clust_if_poss(
 	for (ulint n_tries = 0;
 	     n_tries < BTR_CUR_RETRY_DELETE_N_TIMES;
 	     n_tries++) {
-		if (row_purge_remove_clust_if_poss_low(
-			    node, BTR_MODIFY_TREE | BTR_LATCH_FOR_DELETE)) {
+		if (row_purge_remove_clust_if_poss_low(node, BTR_PURGE_TREE)) {
 			return(true);
 		}
 
@@ -349,10 +348,8 @@ row_purge_remove_sec_if_poss_tree(
 	mtr.start();
 	index->set_modified(mtr);
 
-	search_result = row_search_index_entry(
-				index, entry,
-				BTR_MODIFY_TREE | BTR_LATCH_FOR_DELETE,
-				&pcur, &mtr);
+	search_result = row_search_index_entry(index, entry, BTR_PURGE_TREE,
+					       &pcur, &mtr);
 
 	switch (search_result) {
 	case ROW_NOT_FOUND:

storage/innobase/row/row0uins.cc

@@ -207,9 +207,8 @@ row_undo_ins_remove_clust_rec(
 	} else {
 		index->set_modified(mtr);
 	}
-	ut_a(
-	    node->pcur.restore_position(BTR_MODIFY_TREE | BTR_LATCH_FOR_DELETE,
-	      &mtr) == btr_pcur_t::SAME_ALL);
+	ut_a(node->pcur.restore_position(BTR_PURGE_TREE, &mtr)
+	     == btr_pcur_t::SAME_ALL);
 
 	btr_cur_pessimistic_delete(&err, FALSE, &node->pcur.btr_cur, 0, true,
 				   &mtr);
@@ -272,7 +271,7 @@ row_undo_ins_remove_sec_low(
 		mode = BTR_MODIFY_LEAF | BTR_ALREADY_S_LATCHED;
 		mtr_s_lock_index(index, &mtr);
 	} else {
-		ut_ad(mode == (BTR_MODIFY_TREE | BTR_LATCH_FOR_DELETE));
+		ut_ad(mode == BTR_PURGE_TREE);
 		mtr_sx_lock_index(index, &mtr);
 	}
 
@@ -349,9 +348,7 @@ row_undo_ins_remove_sec(
 
 	/* Try then pessimistic descent to the B-tree */
 retry:
-	err = row_undo_ins_remove_sec_low(
-		BTR_MODIFY_TREE | BTR_LATCH_FOR_DELETE,
-		index, entry, thr);
+	err = row_undo_ins_remove_sec_low(BTR_PURGE_TREE, index, entry, thr);
 
 	/* The delete operation may fail if we have little
 	file space left: TODO: easiest to crash the database

storage/innobase/row/row0umod.cc

@@ -356,8 +356,7 @@ row_undo_mod_clust(
 		}
 
 		mtr.start();
-		if (pcur->restore_position(
-			    BTR_MODIFY_TREE | BTR_LATCH_FOR_DELETE, &mtr) !=
+		if (pcur->restore_position(BTR_PURGE_TREE, &mtr) !=
 		    btr_pcur_t::SAME_ALL) {
 			goto mtr_commit_exit;
 		}
@@ -504,7 +503,7 @@ row_undo_mod_del_mark_or_remove_sec_low(
 			mode = BTR_MODIFY_LEAF | BTR_ALREADY_S_LATCHED;
 			mtr_s_lock_index(index, &mtr);
 		} else {
-			ut_ad(mode == (BTR_MODIFY_TREE | BTR_LATCH_FOR_DELETE));
+			ut_ad(mode == BTR_PURGE_TREE);
 			mtr_sx_lock_index(index, &mtr);
 		}
 	} else {
@@ -634,7 +633,7 @@ row_undo_mod_del_mark_or_remove_sec(
 	}
 
 	err = row_undo_mod_del_mark_or_remove_sec_low(node, thr, index,
-		entry, BTR_MODIFY_TREE | BTR_LATCH_FOR_DELETE);
+		entry, BTR_PURGE_TREE);
 	return(err);
 }