Port parts of r297 from branches/fts:

row_upd_index_replace_new_col_vals_index_pos(): Add a parameter, "ibool
order_only", for limiting the replacement to the ordering fields of the
index. Adjust callers.

 In this port, the comment for the parameter was adjusted to make it clear
 that it only supports clustered indexes.

btr/btr0cur.c

@@ -1606,7 +1606,7 @@ btr_cur_optimistic_update(
 	new_entry = row_rec_to_index_entry(ROW_COPY_DATA, index, rec, heap);
 
 	row_upd_index_replace_new_col_vals_index_pos(new_entry, index, update,
-									NULL);
+		FALSE, NULL);
 	old_rec_size = rec_offs_size(offsets);
 	new_rec_size = rec_get_converted_size(index, new_entry);
 
@@ -1846,7 +1846,7 @@ btr_cur_pessimistic_update(
 	new_entry = row_rec_to_index_entry(ROW_COPY_DATA, index, rec, heap);
 
 	row_upd_index_replace_new_col_vals_index_pos(new_entry, index, update,
-									heap);
+		FALSE, heap);
 	if (!(flags & BTR_KEEP_SYS_FLAG)) {
 		row_upd_index_entry_sys_field(new_entry, index, DATA_ROLL_PTR,
 								roll_ptr);

include/row0upd.h

@@ -185,6 +185,10 @@ row_upd_index_replace_new_col_vals_index_pos(
 	upd_t*		update,	/* in: an update vector built for the index so
 				that the field number in an upd_field is the
 				index position */
+	ibool		order_only,
+				/* in: if TRUE, limit the replacement to
+				ordering fields of index; note that this
+				does not work for non-clustered indexes. */
 	mem_heap_t*	heap);	/* in: memory heap to which we allocate and
 				copy the new values, set this as NULL if you
 				do not want allocation */

row/row0upd.c

@@ -869,6 +869,10 @@ row_upd_index_replace_new_col_vals_index_pos(
 	upd_t*		update,	/* in: an update vector built for the index so
 				that the field number in an upd_field is the
 				index position */
+	ibool		order_only,
+				/* in: if TRUE, limit the replacement to
+				ordering fields of index; note that this
+				does not work for non-clustered indexes. */
 	mem_heap_t*	heap)	/* in: memory heap to which we allocate and
 				copy the new values, set this as NULL if you
 				do not want allocation */
@@ -879,13 +883,20 @@ row_upd_index_replace_new_col_vals_index_pos(
 	dfield_t*	new_val;
 	ulint		j;
 	ulint		i;
+	ulint		n_fields;
 	dtype_t*	cur_type;
 
 	ut_ad(index);
 
 	dtuple_set_info_bits(entry, update->info_bits);
 
-	for (j = 0; j < dict_index_get_n_fields(index); j++) {
+	if (order_only) {
+		n_fields = dict_index_get_n_unique(index);
+	} else {
+		n_fields = dict_index_get_n_fields(index);
+	}
+
+	for (j = 0; j < n_fields; j++) {
 
 		field = dict_index_get_nth_field(index, j);