MDEV-19385: Inconsistent definition of dtuple_get_nth_v_field()

The accessor dtuple_get_nth_v_field() was defined differently between
debug and release builds in MySQL 5.7.8 in
mysql/mysql-server@c47e1751b7
and a debug assertion to document or enforce the questionable assumption
tuple->v_fields == &tuple->fields[tuple->n_fields] was missing.

This was apparently no problem until MDEV-11369 introduced instant
ADD COLUMN to MariaDB Server 10.3. With that work present, in one
test case, trx_undo_report_insert_virtual() could in release builds
fetch the wrong value for a virtual column.

We replace many of the dtuple_t accessors with const-preserving
inline functions, and fix missing or misleadingly applied const
qualifiers accordingly.

storage/innobase/data/data0data.cc

@@ -37,7 +37,7 @@ Created 5/30/1994 Heikki Tuuri
 /** Dummy variable to catch access to uninitialized fields.  In the
 debug version, dtuple_create() will make all fields of dtuple_t point
 to data_error. */
-byte	data_error;
+ut_d(byte data_error);
 #endif /* UNIV_DEBUG */
 
 /** Compare two data tuples.
@@ -416,7 +416,7 @@ dfield_print_also_hex(
 			break;
 		}
 
-		data = static_cast<byte*>(dfield_get_data(dfield));
+		data = static_cast<const byte*>(dfield_get_data(dfield));
 		/* fall through */
 
 	case DATA_BINARY:

storage/innobase/fts/fts0fts.cc

@@ -3366,12 +3366,11 @@ fts_fetch_doc_from_tuple(
                const dict_field_t*     ifield;
                const dict_col_t*       col;
                ulint                   pos;
-               dfield_t*               field;
 
                ifield = dict_index_get_nth_field(index, i);
                col = dict_field_get_col(ifield);
                pos = dict_col_get_no(col);
-               field = dtuple_get_nth_field(tuple, pos);
+		const dfield_t* field = dtuple_get_nth_field(tuple, pos);
 
                if (!get_doc->index_cache->charset) {
                        get_doc->index_cache->charset = fts_get_charset(

storage/innobase/gis/gis0geo.cc

@@ -1,6 +1,7 @@
 /*****************************************************************************
 
 Copyright (c) 2013, 2015, Oracle and/or its affiliates. All Rights Reserved.
+Copyright (c) 2019, MariaDB Corporation.
 
 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
@@ -68,9 +69,9 @@ static
 int
 rtree_add_point_to_mbr(
 /*===================*/
-	uchar**	wkb,		/*!< in: pointer to wkb,
+	const uchar**	wkb,		/*!< in: pointer to wkb,
 				where point is stored */
-	uchar*	end,		/*!< in: end of wkb. */
+	const uchar*	end,		/*!< in: end of wkb. */
 	uint	n_dims,		/*!< in: dimensions. */
 	uchar	byte_order,	/*!< in: byte order. */
 	double*	mbr)		/*!< in/out: mbr, which
@@ -108,9 +109,9 @@ static
 int
 rtree_get_point_mbr(
 /*================*/
-	uchar**	wkb,		/*!< in: pointer to wkb,
+	const uchar**	wkb,		/*!< in: pointer to wkb,
 				where point is stored. */
-	uchar*	end,		/*!< in: end of wkb. */
+	const uchar*	end,		/*!< in: end of wkb. */
 	uint	n_dims,		/*!< in: dimensions. */
 	uchar	byte_order,	/*!< in: byte order. */
 	double*	mbr)		/*!< in/out: mbr,
@@ -127,9 +128,9 @@ static
 int
 rtree_get_linestring_mbr(
 /*=====================*/
-	uchar**	wkb,		/*!< in: pointer to wkb,
+	const uchar**	wkb,		/*!< in: pointer to wkb,
 				where point is stored. */
-	uchar*	end,		/*!< in: end of wkb. */
+	const uchar*	end,		/*!< in: end of wkb. */
 	uint	n_dims,		/*!< in: dimensions. */
 	uchar	byte_order,	/*!< in: byte order. */
 	double*	mbr)		/*!< in/out: mbr,
@@ -158,9 +159,9 @@ static
 int
 rtree_get_polygon_mbr(
 /*==================*/
-	uchar**	wkb,		/*!< in: pointer to wkb,
+	const uchar**	wkb,		/*!< in: pointer to wkb,
 				where point is stored. */
-	uchar*	end,		/*!< in: end of wkb. */
+	const uchar*	end,		/*!< in: end of wkb. */
 	uint	n_dims,		/*!< in: dimensions. */
 	uchar	byte_order,	/*!< in: byte order. */
 	double*	mbr)		/*!< in/out: mbr,
@@ -195,9 +196,9 @@ static
 int
 rtree_get_geometry_mbr(
 /*===================*/
-	uchar**	wkb,		/*!< in: pointer to wkb,
+	const uchar**	wkb,		/*!< in: pointer to wkb,
 				where point is stored. */
-	uchar*	end,		/*!< in: end of wkb. */
+	const uchar*	end,		/*!< in: end of wkb. */
 	uint	n_dims,		/*!< in: dimensions. */
 	double*	mbr,		/*!< in/out: mbr. */
 	int	top)		/*!< in: if it is the top,
@@ -297,7 +298,7 @@ stored in "well-known binary representation" (wkb) format.
 int
 rtree_mbr_from_wkb(
 /*===============*/
-	uchar*	wkb,		/*!< in: wkb */
+	const uchar*	wkb,		/*!< in: wkb */
 	uint	size,		/*!< in: size of wkb. */
 	uint	n_dims,		/*!< in: dimensions. */
 	double*	mbr)		/*!< in/out: mbr, which must

storage/innobase/gis/gis0rtree.cc

@@ -1,6 +1,7 @@
 /*****************************************************************************
 
 Copyright (c) 2016, Oracle and/or its affiliates. All Rights Reserved.
+Copyright (c) 2019, MariaDB Corporation.
 
 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
@@ -64,7 +65,7 @@ rtr_page_split_initialize_nodes(
 	page_t*			page;
 	ulint			n_uniq;
 	ulint			len;
-	byte*			source_cur;
+	const byte*		source_cur;
 
 	block = btr_cur_get_block(cursor);
 	page = buf_block_get_frame(block);
@@ -104,7 +105,7 @@ rtr_page_split_initialize_nodes(
 	}
 
 	/* Put the insert key to node list */
-	source_cur = static_cast<byte*>(dfield_get_data(
+	source_cur = static_cast<const byte*>(dfield_get_data(
 		dtuple_get_nth_field(tuple, 0)));
 	cur->coords = reserve_coords(buf_pos, SPDIMS);
 	rec = (byte*) mem_heap_alloc(
@@ -1874,11 +1875,11 @@ rtr_estimate_n_rows_in_range(
 	ulint		dtuple_f_len MY_ATTRIBUTE((unused));
 	rtr_mbr_t	range_mbr;
 	double		range_area;
-	byte*		range_mbr_ptr;
 
 	dtuple_field = dtuple_get_nth_field(tuple, 0);
 	dtuple_f_len = dfield_get_len(dtuple_field);
-	range_mbr_ptr = reinterpret_cast<byte*>(dfield_get_data(dtuple_field));
+	const byte* range_mbr_ptr = static_cast<const byte*>(
+		dfield_get_data(dtuple_field));
 
 	ut_ad(dtuple_f_len >= DATA_MBR_LEN);
 	rtr_read_mbr(range_mbr_ptr, &range_mbr);

storage/innobase/gis/gis0sea.cc

@@ -1631,15 +1631,13 @@ rtr_get_mbr_from_tuple(
 {
 	const dfield_t* dtuple_field;
         ulint           dtuple_f_len;
-	byte*		data;
 
 	dtuple_field = dtuple_get_nth_field(dtuple, 0);
 	dtuple_f_len = dfield_get_len(dtuple_field);
 	ut_a(dtuple_f_len >= 4 * sizeof(double));
 
-	data = static_cast<byte*>(dfield_get_data(dtuple_field));
+	rtr_read_mbr(static_cast<const byte*>(dfield_get_data(dtuple_field)),
-
+		     mbr);
-	rtr_read_mbr(data, mbr);
 }
 
 /****************************************************************//**

storage/innobase/handler/ha_innodb.cc

@@ -21784,7 +21784,7 @@ void innobase_free_row_for_vcol(VCOL_STORAGE *storage)
 to store the value in passed in "my_rec" */
 dfield_t*
 innobase_get_computed_value(
-	const dtuple_t*		row,
+	dtuple_t*		row,
 	const dict_v_col_t*	col,
 	const dict_index_t*	index,
 	mem_heap_t**		local_heap,

storage/innobase/include/data0data.h

@@ -1,7 +1,7 @@
 /*****************************************************************************
 
 Copyright (c) 1994, 2016, Oracle and/or its affiliates. All Rights Reserved.
-Copyright (c) 2017, 2018, MariaDB Corporation.
+Copyright (c) 2017, 2019, MariaDB Corporation.
 
 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
@@ -31,6 +31,7 @@ Created 5/30/1994 Heikki Tuuri
 #include "data0type.h"
 #include "mem0mem.h"
 #include "dict0types.h"
+#include "btr0types.h"
 
 #include <ostream>
 
@@ -39,29 +40,11 @@ index record which needs external storage of data fields */
 struct big_rec_t;
 struct upd_t;
 
-#ifdef UNIV_DEBUG
+/** Dummy variable to catch access to uninitialized fields.  In the
-/*********************************************************************//**
+debug version, dtuple_create() will make all fields of dtuple_t point
-Gets pointer to the type struct of SQL data field.
+to data_error. */
-@return pointer to the type struct */
+ut_d(extern byte data_error);
-UNIV_INLINE
+
-dtype_t*
-dfield_get_type(
-/*============*/
-	const dfield_t*	field)	/*!< in: SQL data field */
-	MY_ATTRIBUTE((nonnull, warn_unused_result));
-/*********************************************************************//**
-Gets pointer to the data in a field.
-@return pointer to data */
-UNIV_INLINE
-void*
-dfield_get_data(
-/*============*/
-	const dfield_t* field)	/*!< in: field */
-	MY_ATTRIBUTE((nonnull, warn_unused_result));
-#else /* UNIV_DEBUG */
-# define dfield_get_type(field) (&(field)->type)
-# define dfield_get_data(field) ((field)->data)
-#endif /* UNIV_DEBUG */
 /*********************************************************************//**
 Sets the type struct of SQL data field. */
 UNIV_INLINE
@@ -72,15 +55,6 @@ dfield_set_type(
 	const dtype_t*	type);	/*!< in: pointer to data type struct */
 
 /*********************************************************************//**
-Gets length of field data.
-@return length of data; UNIV_SQL_NULL if SQL null data */
-UNIV_INLINE
-ulint
-dfield_get_len(
-/*===========*/
-	const dfield_t* field)	/*!< in: field */
-	MY_ATTRIBUTE((nonnull, warn_unused_result));
-/*********************************************************************//**
 Sets length in a field. */
 UNIV_INLINE
 void
@@ -89,32 +63,6 @@ dfield_set_len(
 	dfield_t*	field,	/*!< in: field */
 	ulint		len)	/*!< in: length or UNIV_SQL_NULL */
 	MY_ATTRIBUTE((nonnull));
-/*********************************************************************//**
-Determines if a field is SQL NULL
-@return nonzero if SQL null data */
-UNIV_INLINE
-ulint
-dfield_is_null(
-/*===========*/
-	const dfield_t* field)	/*!< in: field */
-	MY_ATTRIBUTE((nonnull, warn_unused_result));
-/*********************************************************************//**
-Determines if a field is externally stored
-@return nonzero if externally stored */
-UNIV_INLINE
-ulint
-dfield_is_ext(
-/*==========*/
-	const dfield_t* field)	/*!< in: field */
-	MY_ATTRIBUTE((nonnull, warn_unused_result));
-/*********************************************************************//**
-Sets the "external storage" flag */
-UNIV_INLINE
-void
-dfield_set_ext(
-/*===========*/
-	dfield_t*	field)	/*!< in/out: field */
-	MY_ATTRIBUTE((nonnull));
 
 /** Gets spatial status for "external storage"
 @param[in,out]	field		field */
@@ -221,46 +169,7 @@ dfield_data_is_binary_equal(
 	ulint		len,	/*!< in: data length or UNIV_SQL_NULL */
 	const byte*	data)	/*!< in: data */
 	MY_ATTRIBUTE((nonnull, warn_unused_result));
-/*********************************************************************//**
-Gets number of fields in a data tuple.
-@return number of fields */
-UNIV_INLINE
-ulint
-dtuple_get_n_fields(
-/*================*/
-	const dtuple_t*	tuple)	/*!< in: tuple */
-	MY_ATTRIBUTE((nonnull, warn_unused_result));
-/** Gets number of virtual fields in a data tuple.
-@param[in]	tuple	dtuple to check
-@return number of fields */
-UNIV_INLINE
-ulint
-dtuple_get_n_v_fields(
-	const dtuple_t*	tuple);
 
-#ifdef UNIV_DEBUG
-/** Gets nth field of a tuple.
-@param[in]	tuple	tuple
-@param[in]	n	index of field
-@return nth field */
-UNIV_INLINE
-dfield_t*
-dtuple_get_nth_field(
-	const dtuple_t*	tuple,
-	ulint		n);
-/** Gets nth virtual field of a tuple.
-@param[in]	tuple	tuple
-@oaran[in]	n	the nth field to get
-@return nth field */
-UNIV_INLINE
-dfield_t*
-dtuple_get_nth_v_field(
-	const dtuple_t*	tuple,
-	ulint		n);
-#else /* UNIV_DEBUG */
-# define dtuple_get_nth_field(tuple, n) ((tuple)->fields + (n))
-# define dtuple_get_nth_v_field(tuple, n) ((tuple)->fields + (tuple)->n_fields + (n))
-#endif /* UNIV_DEBUG */
 /*********************************************************************//**
 Gets info bits in a data tuple.
 @return info bits */
@@ -338,19 +247,12 @@ dtuple_create(
 
 /** Initialize the virtual field data in a dtuple_t
 @param[in,out]		vrow	dtuple contains the virtual fields */
-UNIV_INLINE
+UNIV_INLINE void dtuple_init_v_fld(dtuple_t* vrow);
-void
-dtuple_init_v_fld(
-	const dtuple_t*	vrow);
 
 /** Duplicate the virtual field data in a dtuple_t
 @param[in,out]		vrow	dtuple contains the virtual fields
 @param[in]		heap	heap memory to use */
-UNIV_INLINE
+UNIV_INLINE void dtuple_dup_v_fld(dtuple_t* vrow, mem_heap_t* heap);
-void
-dtuple_dup_v_fld(
-	const dtuple_t*	vrow,
-	mem_heap_t*	heap);
 
 /** Creates a data tuple with possible virtual columns to a memory heap.
 @param[in]	heap		memory heap where the tuple is created
@@ -619,6 +521,69 @@ struct dtuple_t {
 #endif /* UNIV_DEBUG */
 };
 
+inline ulint dtuple_get_n_fields(const dtuple_t* tuple)
+{ return tuple->n_fields; }
+inline dtype_t* dfield_get_type(dfield_t* field) { return &field->type; }
+inline const dtype_t* dfield_get_type(const dfield_t* field)
+{ return &field->type; }
+inline void* dfield_get_data(dfield_t* field)
+{
+	ut_ad(field->len == UNIV_SQL_NULL || field->data != &data_error);
+	return field->data;
+}
+inline const void* dfield_get_data(const dfield_t* field)
+{
+	ut_ad(field->len == UNIV_SQL_NULL || field->data != &data_error);
+	return field->data;
+}
+inline ulint dfield_get_len(const dfield_t* field) { return field->len; }
+inline bool dfield_is_null(const dfield_t* field)
+{ return field->len == UNIV_SQL_NULL; }
+/** @return whether a column is to be stored off-page */
+inline bool dfield_is_ext(const dfield_t* field)
+{
+	ut_ad(!field->ext || field->len >= BTR_EXTERN_FIELD_REF_SIZE);
+	return static_cast<bool>(field->ext);
+}
+/** Set the "external storage" flag */
+inline void dfield_set_ext(dfield_t* field) { field->ext = 1; }
+
+/** Gets number of virtual fields in a data tuple.
+@param[in]	tuple	dtuple to check
+@return number of fields */
+inline ulint
+dtuple_get_n_v_fields(const dtuple_t* tuple) { return tuple->n_v_fields; }
+
+inline const dfield_t* dtuple_get_nth_field(const dtuple_t* tuple, ulint n)
+{
+	ut_ad(n < tuple->n_fields);
+	return &tuple->fields[n];
+}
+inline dfield_t* dtuple_get_nth_field(dtuple_t* tuple, ulint n)
+{
+	ut_ad(n < tuple->n_fields);
+	return &tuple->fields[n];
+}
+
+/** Get a virtual column in a table row or an extended clustered index record.
+@param[in]	tuple	tuple
+@oaran[in]	n	the nth virtual field to get
+@return nth virtual field */
+inline const dfield_t* dtuple_get_nth_v_field(const dtuple_t* tuple, ulint n)
+{
+	ut_ad(n < tuple->n_v_fields);
+	return &tuple->v_fields[n];
+}
+/** Get a virtual column in a table row or an extended clustered index record.
+@param[in]	tuple	tuple
+@oaran[in]	n	the nth virtual field to get
+@return nth virtual field */
+inline dfield_t* dtuple_get_nth_v_field(dtuple_t* tuple, ulint n)
+{
+	ut_ad(n < tuple->n_v_fields);
+	return &tuple->v_fields[n];
+}
+
 /** A slot for a field in a big rec vector */
 struct big_rec_field_t {
 

storage/innobase/include/data0data.ic

@@ -24,28 +24,7 @@ SQL data field and tuple
 Created 5/30/1994 Heikki Tuuri
 *************************************************************************/
 
-#include "mem0mem.h"
 #include "ut0rnd.h"
-#include "btr0types.h"
-
-#ifdef UNIV_DEBUG
-/** Dummy variable to catch access to uninitialized fields.  In the
-debug version, dtuple_create() will make all fields of dtuple_t point
-to data_error. */
-extern byte data_error;
-
-/*********************************************************************//**
-Gets pointer to the type struct of SQL data field.
-@return pointer to the type struct */
-UNIV_INLINE
-dtype_t*
-dfield_get_type(
-/*============*/
-	const dfield_t*	field)	/*!< in: SQL data field */
-{
-	return((dtype_t*) &(field->type));
-}
-#endif /* UNIV_DEBUG */
 
 /*********************************************************************//**
 Sets the type struct of SQL data field. */
@@ -62,38 +41,6 @@ dfield_set_type(
 	field->type = *type;
 }
 
-#ifdef UNIV_DEBUG
-/*********************************************************************//**
-Gets pointer to the data in a field.
-@return pointer to data */
-UNIV_INLINE
-void*
-dfield_get_data(
-/*============*/
-	const dfield_t* field)	/*!< in: field */
-{
-	ut_ad((field->len == UNIV_SQL_NULL)
-	      || (field->data != &data_error));
-
-	return((void*) field->data);
-}
-#endif /* UNIV_DEBUG */
-
-/*********************************************************************//**
-Gets length of field data.
-@return length of data; UNIV_SQL_NULL if SQL null data */
-UNIV_INLINE
-ulint
-dfield_get_len(
-/*===========*/
-	const dfield_t*	field)	/*!< in: field */
-{
-	ut_ad((field->len == UNIV_SQL_NULL)
-	      || (field->data != &data_error));
-
-	return(field->len);
-}
-
 /*********************************************************************//**
 Sets length in a field. */
 UNIV_INLINE
@@ -111,42 +58,6 @@ dfield_set_len(
 	field->len = static_cast<unsigned int>(len);
 }
 
-/*********************************************************************//**
-Determines if a field is SQL NULL
-@return nonzero if SQL null data */
-UNIV_INLINE
-ulint
-dfield_is_null(
-/*===========*/
-	const dfield_t* field)	/*!< in: field */
-{
-	return(field->len == UNIV_SQL_NULL);
-}
-
-/*********************************************************************//**
-Determines if a field is externally stored
-@return nonzero if externally stored */
-UNIV_INLINE
-ulint
-dfield_is_ext(
-/*==========*/
-	const dfield_t* field)	/*!< in: field */
-{
-	ut_ad(!field->ext || field->len >= BTR_EXTERN_FIELD_REF_SIZE);
-	return(field->ext);
-}
-
-/*********************************************************************//**
-Sets the "external storage" flag */
-UNIV_INLINE
-void
-dfield_set_ext(
-/*===========*/
-	dfield_t*	field)	/*!< in/out: field */
-{
-	field->ext = 1;
-}
-
 /** Gets spatial status for "external storage"
 @param[in,out]	field		field */
 UNIV_INLINE
@@ -366,63 +277,6 @@ dtuple_set_n_fields_cmp(
 	tuple->n_fields_cmp = n_fields_cmp;
 }
 
-/*********************************************************************//**
-Gets number of fields in a data tuple.
-@return number of fields */
-UNIV_INLINE
-ulint
-dtuple_get_n_fields(
-/*================*/
-	const dtuple_t*	tuple)	/*!< in: tuple */
-{
-	return(tuple->n_fields);
-}
-
-/** Gets the number of virtual fields in a data tuple.
-@param[in]	tuple	dtuple to check
-@return number of fields */
-UNIV_INLINE
-ulint
-dtuple_get_n_v_fields(
-	const dtuple_t*	tuple)
-{
-	ut_ad(tuple);
-
-	return(tuple->n_v_fields);
-}
-#ifdef UNIV_DEBUG
-/** Gets nth field of a tuple.
-@param[in]	tuple	tuple
-@param[in]	n	index of field
-@return nth field */
-UNIV_INLINE
-dfield_t*
-dtuple_get_nth_field(
-	const dtuple_t*	tuple,
-	ulint		n)
-{
-	ut_ad(tuple);
-	ut_ad(n < tuple->n_fields);
-
-	return((dfield_t*) tuple->fields + n);
-}
-/** Gets nth virtual field of a tuple.
-@param[in]	tuple	tuple
-@oaran[in]	n	the nth field to get
-@return nth field */
-UNIV_INLINE
-dfield_t*
-dtuple_get_nth_v_field(
-	const dtuple_t*	tuple,
-	ulint		n)
-{
-	ut_ad(tuple);
-	ut_ad(n < tuple->n_v_fields);
-
-	return(static_cast<dfield_t*>(tuple->v_fields + n));
-}
-#endif /* UNIV_DEBUG */
-
 /** Creates a data tuple from an already allocated chunk of memory.
 The size of the chunk must be at least DTUPLE_EST_ALLOC(n_fields).
 The default value for number of fields used in record comparisons
@@ -487,12 +341,10 @@ dtuple_create_from_mem(
 
 /** Duplicate the virtual field data in a dtuple_t
 @param[in,out]		vrow	dtuple contains the virtual fields
-@param[in]		heap	heap memory to use */
+@param[in,out]		heap	heap memory to use */
 UNIV_INLINE
 void
-dtuple_dup_v_fld(
+dtuple_dup_v_fld(dtuple_t* vrow, mem_heap_t* heap)
-	const dtuple_t*	vrow,
-	mem_heap_t*	heap)
 {
 	for (ulint i = 0; i < vrow->n_v_fields; i++) {
 		dfield_t*       dfield = dtuple_get_nth_v_field(vrow, i);
@@ -504,8 +356,7 @@ dtuple_dup_v_fld(
 @param[in,out]		vrow	dtuple contains the virtual fields */
 UNIV_INLINE
 void
-dtuple_init_v_fld(
+dtuple_init_v_fld(dtuple_t* vrow)
-	const dtuple_t*	vrow)
 {
 	for (ulint i = 0; i < vrow->n_v_fields; i++) {
 		dfield_t*       dfield = dtuple_get_nth_v_field(vrow, i);

storage/innobase/include/gis0geo.h

@@ -1,5 +1,6 @@
 /*****************************************************************************
 Copyright (c) 2014, 2015, Oracle and/or its affiliates. All rights reserved.
+Copyright (c) 2019, MariaDB Corporation.
 
 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
@@ -73,7 +74,7 @@ stored in "well-known binary representation" (wkb) format.
 int
 rtree_mbr_from_wkb(
 /*===============*/
-	uchar*	wkb,		/*!< in: pointer to wkb. */
+	const uchar*	wkb,		/*!< in: pointer to wkb. */
 	uint	size,		/*!< in: size of wkb. */
 	uint	n_dims,		/*!< in: dimensions. */
 	double*	mbr);		/*!< in/out: mbr. */

storage/innobase/include/rem0cmp.ic

@@ -127,10 +127,10 @@ cmp_dfield_dfield_like_prefix(
 	if (CHARSET_INFO* cs = get_charset(cs_num, MYF(MY_WME))) {
 		return(cs->coll->strnncoll(
 			       cs,
-			       static_cast<uchar*>(
+			       static_cast<const uchar*>(
 				       dfield_get_data(dfield1)),
 			       dfield_get_len(dfield1),
-			       static_cast<uchar*>(
+			       static_cast<const uchar*>(
 				       dfield_get_data(dfield2)),
 			       dfield_get_len(dfield2),
 			       1));

storage/innobase/include/row0mysql.h

@@ -858,7 +858,7 @@ void innobase_free_row_for_vcol(VCOL_STORAGE *storage);
 @return the field filled with computed value */
 dfield_t*
 innobase_get_computed_value(
-	const dtuple_t*		row,
+	dtuple_t*		row,
 	const dict_v_col_t*	col,
 	const dict_index_t*	index,
 	mem_heap_t**		local_heap,

storage/innobase/include/row0vers.h

@@ -1,7 +1,7 @@
 /*****************************************************************************
 
 Copyright (c) 1997, 2016, Oracle and/or its affiliates. All Rights Reserved.
-Copyright (c) 2017, MariaDB Corporation.
+Copyright (c) 2017, 2019, MariaDB Corporation.
 
 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
@@ -124,7 +124,7 @@ row_vers_build_for_consistent_read(
 				if the history is missing or the record
 				does not exist in the view, that is,
 				it was freshly inserted afterwards */
-	const dtuple_t**vrow);	/*!< out: reports virtual column info if any */
+	dtuple_t**	vrow);	/*!< out: reports virtual column info if any */
 
 /*****************************************************************//**
 Constructs the last committed version of a clustered index record,
@@ -149,7 +149,7 @@ row_vers_build_for_semi_consistent_read(
 	const rec_t**	old_vers,/*!< out: rec, old version, or NULL if the
 				record does not exist in the view, that is,
 				it was freshly inserted afterwards */
-	const dtuple_t**vrow);	/*!< out: holds virtual column info if any
+	dtuple_t**	vrow);	/*!< out: holds virtual column info if any
 				is updated in the view */
 
 #endif

storage/innobase/include/trx0rec.h

@@ -1,7 +1,7 @@
 /*****************************************************************************
 
 Copyright (c) 1996, 2016, Oracle and/or its affiliates. All Rights Reserved.
-Copyright (c) 2017, 2018, MariaDB Corporation.
+Copyright (c) 2017, 2019, MariaDB Corporation.
 
 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
@@ -250,7 +250,7 @@ trx_undo_prev_version_build(
 				dtuple if it is not yet created. This heap
 				diffs from "heap" above in that it could be
 				prebuilt->old_vers_heap for selection */
-	const dtuple_t**vrow,	/*!< out: virtual column info, if any */
+	dtuple_t**	vrow,	/*!< out: virtual column info, if any */
 	ulint		v_status);
 				/*!< in: status determine if it is going
 				into this function by purge thread or not.
@@ -299,7 +299,7 @@ void
 trx_undo_read_v_cols(
 	const dict_table_t*	table,
 	const byte*		ptr,
-	const dtuple_t*		row,
+	dtuple_t*		row,
 	bool			in_purge);
 
 /** Read virtual column index from undo log if the undo log contains such

storage/innobase/rem/rem0rec.cc

@@ -838,9 +838,7 @@ rec_get_converted_size_comp_prefix_low(
 		col = dict_field_get_col(field);
 
 #ifdef UNIV_DEBUG
-		dtype_t*	type;
+		const dtype_t* type = dfield_get_type(&fields[i]);
-
-		type = dfield_get_type(&fields[i]);
 		if (dict_index_is_spatial(index)) {
 			if (DATA_GEOMETRY_MTYPE(col->mtype) && i == 0) {
 				ut_ad(type->prtype & DATA_GIS_MBR);

storage/innobase/row/row0ins.cc

@@ -3327,14 +3327,14 @@ row_ins_spatial_index_entry_set_mbr_field(
 	dfield_t*	field,		/*!< in/out: mbr field */
 	const dfield_t*	row_field)	/*!< in: row field */
 {
-	uchar*		dptr = NULL;
 	ulint		dlen = 0;
 	double		mbr[SPDIMS * 2];
 
 	/* This must be a GEOMETRY datatype */
 	ut_ad(DATA_GEOMETRY_MTYPE(field->type.mtype));
 
-	dptr = static_cast<uchar*>(dfield_get_data(row_field));
+	const byte* dptr = static_cast<const byte*>(
+		dfield_get_data(row_field));
 	dlen = dfield_get_len(row_field);
 
 	/* obtain the MBR */

storage/innobase/row/row0merge.cc

@@ -453,7 +453,7 @@ row_merge_buf_redundant_convert(
 	ut_ad(field_len <= len);
 
 	if (row_field->ext) {
-		const byte*	field_data = static_cast<byte*>(
+		const byte*	field_data = static_cast<const byte*>(
 			dfield_get_data(row_field));
 		ulint		ext_len;
 
@@ -483,7 +483,7 @@ row_merge_buf_redundant_convert(
 @param[in]	old_table	original table
 @param[in]	new_table	new table
 @param[in,out]	psort_info	parallel sort info
-@param[in]	row		table row
+@param[in,out]	row		table row
 @param[in]	ext		cache of externally stored
 				column prefixes, or NULL
 @param[in,out]	doc_id		Doc ID if we are creating
@@ -505,7 +505,7 @@ row_merge_buf_add(
 	const dict_table_t*	old_table,
 	const dict_table_t*	new_table,
 	fts_psort_t*		psort_info,
-	const dtuple_t*		row,
+	dtuple_t*		row,
 	const row_ext_t*	ext,
 	doc_id_t*		doc_id,
 	mem_heap_t*		conv_heap,
@@ -642,7 +642,7 @@ row_merge_buf_add(
 						row,
 						index->table->fts->doc_col);
 					*doc_id = (doc_id_t) mach_read_from_8(
-						static_cast<byte*>(
+						static_cast<const byte*>(
 						dfield_get_data(doc_field)));
 
 					if (*doc_id == 0) {
@@ -1904,7 +1904,7 @@ row_merge_read_clustered_index(
 
 		const rec_t*	rec;
 		ulint*		offsets;
-		const dtuple_t*	row;
+		dtuple_t*	row;
 		row_ext_t*	ext;
 		page_cur_t*	cur	= btr_pcur_get_page_cur(&pcur);
 
@@ -2154,9 +2154,8 @@ end_of_index:
 			ut_ad(add_autoinc
 			      < dict_table_get_n_user_cols(new_table));
 
-			const dfield_t*	dfield;
+			dfield_t* dfield = dtuple_get_nth_field(row,
-
+								add_autoinc);
-			dfield = dtuple_get_nth_field(row, add_autoinc);
 			if (dfield_is_null(dfield)) {
 				goto write_buffers;
 			}

storage/innobase/row/row0row.cc

@@ -95,7 +95,7 @@ row_build_index_entry_low(
 		const dict_col_t*	col;
 		ulint			col_no = 0;
 		dfield_t*		dfield;
-		dfield_t*		dfield2;
+		const dfield_t*		dfield2;
 		ulint			len;
 
 		if (i >= entry_len) {
@@ -162,7 +162,7 @@ row_build_index_entry_low(
 			dfield_set_data(dfield, mbr, mbr_len);
 
 			if (dfield2->data) {
-				uchar*	dptr = NULL;
+				const uchar* dptr = NULL;
 				ulint	dlen = 0;
 				ulint	flen = 0;
 				double	tmp_mbr[SPDIMS * 2];
@@ -170,7 +170,7 @@ row_build_index_entry_low(
 
 				if (dfield_is_ext(dfield2)) {
 					if (flag == ROW_BUILD_FOR_PURGE) {
-						byte*	ptr = NULL;
+						const byte*	ptr = NULL;
 
 						spatial_status_t spatial_status;
 						spatial_status =
@@ -179,7 +179,7 @@ row_build_index_entry_low(
 
 						switch (spatial_status) {
 						case SPATIAL_ONLY:
-						ptr = static_cast<byte*>(
+						ptr = static_cast<const byte*>(
 							dfield_get_data(
 								dfield2));
 						ut_ad(dfield_get_len(dfield2)
@@ -187,7 +187,7 @@ row_build_index_entry_low(
 						break;
 
 						case SPATIAL_MIXED:
-						ptr = static_cast<byte*>(
+						ptr = static_cast<const byte*>(
 							dfield_get_data(
 								dfield2))
 							+ dfield_get_len(
@@ -216,13 +216,13 @@ row_build_index_entry_low(
 						flen = BTR_EXTERN_FIELD_REF_SIZE;
 						ut_ad(dfield_get_len(dfield2) >=
 						      BTR_EXTERN_FIELD_REF_SIZE);
-						dptr = static_cast<byte*>(
+						dptr = static_cast<const byte*>(
 							dfield_get_data(dfield2))
 							+ dfield_get_len(dfield2)
 							- BTR_EXTERN_FIELD_REF_SIZE;
 					} else {
 						flen = dfield_get_len(dfield2);
-						dptr = static_cast<byte*>(
+						dptr = static_cast<const byte*>(
 							dfield_get_data(dfield2));
 					}
 
@@ -240,7 +240,7 @@ row_build_index_entry_low(
 						flen,
 						temp_heap);
 				} else {
-					dptr = static_cast<uchar*>(
+					dptr = static_cast<const uchar*>(
 						dfield_get_data(dfield2));
 					dlen = dfield_get_len(dfield2);
 

storage/innobase/row/row0sel.cc

@@ -222,7 +222,6 @@ row_sel_sec_rec_is_for_clust_rec(
 		reconstructed from base column in cluster index */
 		if (is_virtual) {
 			const dict_v_col_t*	v_col;
-			const dtuple_t*         row;
 			dfield_t*		vfield;
 			row_ext_t*		ext;
 
@@ -239,7 +238,8 @@ row_sel_sec_rec_is_for_clust_rec(
 
 			v_col = reinterpret_cast<const dict_v_col_t*>(col);
 
-			row = row_build(ROW_COPY_POINTERS,
+			dtuple_t* row = row_build(
+				ROW_COPY_POINTERS,
 				clust_index, clust_rec,
 				clust_offs,
 				NULL, NULL, NULL, &ext, heap);
@@ -804,7 +804,7 @@ row_sel_build_committed_vers_for_mysql(
 					record does not exist in the view:
 					i.e., it was freshly inserted
 					afterwards */
-	const dtuple_t**vrow,		/*!< out: to be filled with old virtual
+	dtuple_t**	vrow,		/*!< out: to be filled with old virtual
 					column version if any */
 	mtr_t*		mtr)		/*!< in: mtr */
 {
@@ -3291,7 +3291,7 @@ row_sel_build_prev_vers_for_mysql(
 					record does not exist in the view:
 					i.e., it was freshly inserted
 					afterwards */
-	const dtuple_t**vrow,		/*!< out: dtuple to hold old virtual
+	dtuple_t**	vrow,		/*!< out: dtuple to hold old virtual
 					column data */
 	mtr_t*		mtr)		/*!< in: mtr */
 {
@@ -3335,7 +3335,7 @@ row_sel_get_clust_rec_for_mysql(
 				rec_get_offsets(out_rec, clust_index) */
 	mem_heap_t**	offset_heap,/*!< in/out: memory heap from which
 				the offsets are allocated */
-	const dtuple_t**vrow,	/*!< out: virtual column to fill */
+	dtuple_t**	vrow,	/*!< out: virtual column to fill */
 	mtr_t*		mtr)	/*!< in: mtr used to get access to the
 				non-clustered record; the same mtr is used to
 				access the clustered index */
@@ -4038,7 +4038,7 @@ void
 row_sel_fill_vrow(
 	const rec_t*		rec,
 	dict_index_t*		index,
-	const dtuple_t**	vrow,
+	dtuple_t**		vrow,
 	mem_heap_t*		heap)
 {
 	ulint           offsets_[REC_OFFS_NORMAL_SIZE];
@@ -4230,7 +4230,7 @@ row_search_mvcc(
 	dict_index_t*	clust_index;
 	que_thr_t*	thr;
 	const rec_t*	rec;
-	const dtuple_t*	vrow = NULL;
+	dtuple_t*	vrow = NULL;
 	const rec_t*	result_rec = NULL;
 	const rec_t*	clust_rec;
 	dberr_t		err				= DB_SUCCESS;

storage/innobase/row/row0upd.cc

@@ -856,7 +856,7 @@ row_upd_index_write_log(
 
 				mlog_catenate_string(
 					mtr,
-					static_cast<byte*>(
+					static_cast<const byte*>(
 						dfield_get_data(new_val)),
 					len);
 
@@ -1052,8 +1052,6 @@ row_upd_build_difference_binary(
 	dberr_t*	error)
 {
 	upd_field_t*	upd_field;
-	dfield_t*	dfield;
-	const byte*	data;
 	ulint		len;
 	upd_t*		update;
 	ulint		n_diff;
@@ -1084,10 +1082,8 @@ row_upd_build_difference_binary(
 	}
 
 	for (i = 0; i < n_fld; i++) {
-
+		const byte* data = rec_get_nth_field(rec, offsets, i, &len);
-		data = rec_get_nth_field(rec, offsets, i, &len);
+		const dfield_t* dfield = dtuple_get_nth_field(entry, i);
-
-		dfield = dtuple_get_nth_field(entry, i);
 
 		/* NOTE: we compare the fields as binary strings!
 		(No collation) */
@@ -1155,8 +1151,6 @@ row_upd_build_difference_binary(
 					index->table, NULL, NULL, &ext, heap);
 			}
 
-			dfield = dtuple_get_nth_v_field(entry, i);
-
 			dfield_t*	vfield = innobase_get_computed_value(
 				update->old_vrow, col, index,
 				&v_heap, heap, NULL, thd, mysql_table, record,
@@ -1167,6 +1161,9 @@ row_upd_build_difference_binary(
 				return(NULL);
 			}
 
+			const dfield_t* dfield = dtuple_get_nth_v_field(
+				entry, i);
+
 			if (!dfield_data_is_binary_equal(
 				dfield, vfield->len,
 				static_cast<byte*>(vfield->data))) {
@@ -1771,7 +1768,7 @@ row_upd_changes_ord_field_binary_func(
 			double		mbr2[SPDIMS * 2];
 			rtr_mbr_t*	old_mbr;
 			rtr_mbr_t*	new_mbr;
-			uchar*		dptr = NULL;
+			const uchar*	dptr = NULL;
 			ulint		flen = 0;
 			ulint		dlen = 0;
 			mem_heap_t*	temp_heap = NULL;
@@ -1792,7 +1789,7 @@ row_upd_changes_ord_field_binary_func(
 				/* For off-page stored data, we
 				need to read the whole field data. */
 				flen = dfield_get_len(dfield);
-				dptr = static_cast<byte*>(
+				dptr = static_cast<const byte*>(
 					dfield_get_data(dfield));
 				temp_heap = mem_heap_create(1000);
 
@@ -1802,7 +1799,7 @@ row_upd_changes_ord_field_binary_func(
 					flen,
 					temp_heap);
 			} else {
-				dptr = static_cast<uchar*>(dfield->data);
+				dptr = static_cast<const uchar*>(dfield->data);
 				dlen = dfield->len;
 			}
 
@@ -1822,13 +1819,13 @@ row_upd_changes_ord_field_binary_func(
 					flen = BTR_EXTERN_FIELD_REF_SIZE;
 					ut_ad(dfield_get_len(new_field) >=
 					      BTR_EXTERN_FIELD_REF_SIZE);
-					dptr = static_cast<byte*>(
+					dptr = static_cast<const byte*>(
 						dfield_get_data(new_field))
 						+ dfield_get_len(new_field)
 						- BTR_EXTERN_FIELD_REF_SIZE;
 				} else {
 					flen = dfield_get_len(new_field);
-					dptr = static_cast<byte*>(
+					dptr = static_cast<const byte*>(
 						dfield_get_data(new_field));
 				}
 
@@ -1842,7 +1839,8 @@ row_upd_changes_ord_field_binary_func(
 					flen,
 					temp_heap);
 			} else {
-				dptr = static_cast<uchar*>(upd_field->new_val.data);
+				dptr = static_cast<const byte*>(
+					upd_field->new_val.data);
 				dlen = upd_field->new_val.len;
 			}
 			rtree_mbr_from_wkb(dptr + GEO_DATA_HEADER_SIZE,
@@ -1900,7 +1898,7 @@ row_upd_changes_ord_field_binary_func(
 			ut_a(dict_index_is_clust(index)
 			     || ind_field->prefix_len <= dfield_len);
 
-			buf = static_cast<byte*>(dfield_get_data(dfield));
+			buf= static_cast<const byte*>(dfield_get_data(dfield));
 copy_dfield:
 			ut_a(dfield_len > 0);
 			dfield_copy(&dfield_ext, dfield);

storage/innobase/row/row0vers.cc

@@ -1,7 +1,7 @@
 /*****************************************************************************
 
 Copyright (c) 1997, 2017, Oracle and/or its affiliates. All Rights Reserved.
-Copyright (c) 2017, 2018, MariaDB Corporation.
+Copyright (c) 2017, 2019, MariaDB Corporation.
 
 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
@@ -98,7 +98,7 @@ row_vers_impl_x_locked_low(
 	mem_heap_t*	heap;
 	dtuple_t*	ientry = NULL;
 	mem_heap_t*	v_heap = NULL;
-	const dtuple_t*	cur_vrow = NULL;
+	dtuple_t*	cur_vrow = NULL;
 
 	DBUG_ENTER("row_vers_impl_x_locked_low");
 
@@ -165,7 +165,7 @@ row_vers_impl_x_locked_low(
 		ulint		vers_del;
 		trx_id_t	prev_trx_id;
 		mem_heap_t*	old_heap = heap;
-		const dtuple_t*	vrow = NULL;
+		dtuple_t*	vrow = NULL;
 
 		/* We keep the semaphore in mtr on the clust_rec page, so
 		that no other transaction can update it and get an
@@ -519,7 +519,7 @@ row_vers_build_cur_vrow_low(
 	roll_ptr_t		roll_ptr,
 	trx_id_t		trx_id,
 	mem_heap_t*		v_heap,
-	const dtuple_t**	vrow,
+	dtuple_t**		vrow,
 	mtr_t*			mtr)
 {
 	const rec_t*	version;
@@ -636,7 +636,7 @@ row_vers_vc_matches_cluster(
 	roll_ptr_t	roll_ptr,
 	trx_id_t	trx_id,
 	mem_heap_t*	v_heap,
-	const dtuple_t**vrow,
+	dtuple_t**	vrow,
 	mtr_t*		mtr)
 {
 	const rec_t*	version;
@@ -801,7 +801,7 @@ func_exit:
 @param[in,out]	vcol_info	virtual column information for purge thread
 @return dtuple contains virtual column data */
 static
-const dtuple_t*
+dtuple_t*
 row_vers_build_cur_vrow(
 	bool			in_purge,
 	const rec_t*		rec,
@@ -816,7 +816,7 @@ row_vers_build_cur_vrow(
 	mtr_t*			mtr,
 	purge_vcol_info_t*	vcol_info)
 {
-	const dtuple_t*	cur_vrow = NULL;
+	dtuple_t* cur_vrow = NULL;
 
 	roll_ptr_t t_roll_ptr = row_get_rec_roll_ptr(
 		rec, clust_index, *clust_offsets);
@@ -897,9 +897,9 @@ row_vers_old_has_index_entry(
 	dtuple_t*	row;
 	const dtuple_t*	entry;
 	ulint		comp;
-	const dtuple_t*	vrow = NULL;
+	dtuple_t*	vrow = NULL;
 	mem_heap_t*	v_heap = NULL;
-	const dtuple_t*	cur_vrow = NULL;
+	dtuple_t*	cur_vrow = NULL;
 
 	ut_ad(mtr_memo_contains_page_flagged(mtr, rec, MTR_MEMO_PAGE_X_FIX
 					     | MTR_MEMO_PAGE_S_FIX));
@@ -1162,7 +1162,7 @@ row_vers_build_for_consistent_read(
 				if the history is missing or the record
 				does not exist in the view, that is,
 				it was freshly inserted afterwards */
-	const dtuple_t**vrow)	/*!< out: virtual row */
+	dtuple_t**	vrow)	/*!< out: virtual row */
 {
 	const rec_t*	version;
 	rec_t*		prev_version;
@@ -1275,7 +1275,7 @@ row_vers_build_for_semi_consistent_read(
 	const rec_t**	old_vers,/*!< out: rec, old version, or NULL if the
 				record does not exist in the view, that is,
 				it was freshly inserted afterwards */
-	const dtuple_t** vrow)	/*!< out: virtual row, old version, or NULL
+	dtuple_t**	vrow)	/*!< out: virtual row, old version, or NULL
 				if it is not updated in the view */
 {
 	const rec_t*	version;

storage/innobase/trx/trx0rec.cc

@@ -388,8 +388,6 @@ trx_undo_report_insert_virtual(
 
 	for (ulint col_no = 0; col_no < dict_table_get_n_v_cols(table);
 	     col_no++) {
-		dfield_t*       vfield = NULL;
-
 		const dict_v_col_t*     col
 			= dict_table_get_nth_v_col(table, col_no);
 
@@ -412,7 +410,8 @@ trx_undo_report_insert_virtual(
 				return(false);
 			}
 
-			vfield = dtuple_get_nth_v_field(row, col->v_pos);
+			const dfield_t* vfield = dtuple_get_nth_v_field(
+				row, col->v_pos);
 			ulint	flen = vfield->len;
 
 			if (flen != UNIV_SQL_NULL) {
@@ -1331,8 +1330,6 @@ already_logged:
 
 		for (col_no = 0; col_no < dict_table_get_n_v_cols(table);
 		     col_no++) {
-			dfield_t*	vfield = NULL;
-
 			const dict_v_col_t*     col
 				= dict_table_get_nth_v_col(table, col_no);
 
@@ -1362,6 +1359,8 @@ already_logged:
 					 return(0);
 				}
 
+				const dfield_t* vfield = NULL;
+
 				if (update) {
 					ut_ad(!row);
 					if (update->old_vrow == NULL) {
@@ -2300,7 +2299,7 @@ trx_undo_prev_version_build(
 				dtuple if it is not yet created. This heap
 				diffs from "heap" above in that it could be
 				prebuilt->old_vers_heap for selection */
-	const dtuple_t**vrow,	/*!< out: virtual column info, if any */
+	dtuple_t**	vrow,	/*!< out: virtual column info, if any */
 	ulint		v_status)
 				/*!< in: status determine if it is going
 				into this function by purge thread or not.
@@ -2503,7 +2502,7 @@ void
 trx_undo_read_v_cols(
 	const dict_table_t*	table,
 	const byte*		ptr,
-	const dtuple_t*		row,
+	dtuple_t*		row,
 	bool			in_purge)
 {
 	const byte*     end_ptr;