Revert an InnoDB Memcached plugin fix that was merged from MySQL 5.6.37

Revert the following change, because Memcached is not present
in MariaDB Server. We had better avoid adding dead code.

commit d9bc5e03d788b958ce8c76e157239953db60adb2
Author: Aakanksha Verma <aakanksha.verma@oracle.com>
Date:   Thu May 18 14:31:01 2017 +0530

    Bug #24605783 MYSQL GOT SIGNAL 6 ASSERTION FAILURE

storage/innobase/api/api0api.cc

 /*****************************************************************************
 
-Copyright (c) 2008, 2017, Oracle and/or its affiliates. All Rights Reserved.
+Copyright (c) 2008, 2015, Oracle and/or its affiliates. All Rights Reserved.
 
 This program is free software; you can redistribute it and/or modify it under
 the terms of the GNU General Public License as published by the Free Software
@@ -1988,14 +1988,11 @@ ib_cursor_read_row(
 
 			page_format = static_cast<ib_bool_t>(
 				dict_table_is_comp(tuple->index->table));
-
 			rec = btr_pcur_get_rec(pcur);
 
-			if (!rec_get_deleted_flag(rec, page_format)) {
-				if (prebuilt->innodb_api &&
-					prebuilt->innodb_api_rec != NULL) {
-					rec =prebuilt->innodb_api_rec;
-				}
+			if (prebuilt->innodb_api_rec &&
+			    prebuilt->innodb_api_rec != rec) {
+				rec = prebuilt->innodb_api_rec;
 			}
 
 			if (!rec_get_deleted_flag(rec, page_format)) {
@@ -2032,10 +2029,6 @@ ib_cursor_position(
 
 	buf = static_cast<unsigned char*>(mem_alloc(UNIV_PAGE_SIZE));
 
-	if (prebuilt->innodb_api) {
-                prebuilt->cursor_heap = cursor->heap;
-        }
-
 	/* We want to position at one of the ends, row_search_for_mysql()
 	uses the search_tuple fields to work out what to do. */
 	dtuple_set_n_fields(prebuilt->search_tuple, 0);
@@ -2090,9 +2083,6 @@ ib_cursor_next(
         row_prebuilt_t* prebuilt = cursor->prebuilt;
 	byte		buf[UNIV_PAGE_SIZE_MAX];
 
-	if (prebuilt->innodb_api) {
-                prebuilt->cursor_heap = cursor->heap;
-        }
         /* We want to move to the next record */
         dtuple_set_n_fields(prebuilt->search_tuple, 0);
 
@@ -2145,9 +2135,6 @@ ib_cursor_moveto(
 
 	buf = static_cast<unsigned char*>(mem_alloc(UNIV_PAGE_SIZE));
 
-	if (prebuilt->innodb_api) {
-		prebuilt->cursor_heap = cursor->heap;
-	}
 	err = static_cast<ib_err_t>(row_search_for_mysql(
 		buf, ib_srch_mode, prebuilt, cursor->match_mode, 0));
 

storage/innobase/include/row0mysql.h

 /*****************************************************************************
 
-Copyright (c) 2000, 2017, Oracle and/or its affiliates. All Rights Reserved.
+Copyright (c) 2000, 2016, Oracle and/or its affiliates. All Rights Reserved.
 
 This program is free software; you can redistribute it and/or modify it under
 the terms of the GNU General Public License as published by the Free Software
@@ -724,8 +724,6 @@ struct row_prebuilt_t {
 	mem_heap_t*	heap;		/*!< memory heap from which
 					these auxiliary structures are
 					allocated when needed */
-	mem_heap_t*	cursor_heap;    /*!< memory heap from which
-					innodb_api_buf is allocated per session*/
 	ins_node_t*	ins_node;	/*!< Innobase SQL insert node
 					used to perform inserts
 					to the table */
@@ -876,9 +874,6 @@ struct row_prebuilt_t {
 	unsigned	innodb_api:1;	/*!< whether this is a InnoDB API
 					query */
 	const rec_t*	innodb_api_rec;	/*!< InnoDB API search result */
-	void*		innodb_api_buf; /*!< Buffer holding copy of the physical
-					Innodb API search record */
-	ulint		innodb_api_rec_size; /*!< Size of the Innodb API record */
 	byte*		srch_key_val1;  /*!< buffer used in converting
 					search key values from MySQL format
 					to InnoDB format.*/

storage/innobase/row/row0sel.cc

@@ -4997,19 +4997,8 @@ row_search_for_mysql(
 
 		btr_pcur_store_position(pcur, &mtr);
 
-		if (prebuilt->innodb_api
-		    && (btr_pcur_get_rec(pcur) != result_rec)) {
-			ulint rec_size =  rec_offs_size(offsets);
-			if (!prebuilt->innodb_api_rec_size ||
-			   (prebuilt->innodb_api_rec_size < rec_size)) {
-				prebuilt->innodb_api_buf =
-				  static_cast<byte*>
-				  (mem_heap_alloc(prebuilt->cursor_heap,rec_size));
-				prebuilt->innodb_api_rec_size = rec_size;
-			}
-			prebuilt->innodb_api_rec =
-			      rec_copy(
-			       prebuilt->innodb_api_buf, result_rec, offsets);
+		if (prebuilt->innodb_api) {
+			prebuilt->innodb_api_rec = result_rec;
 		}
 	}