branches/zip: dtuple_convert_big_rec(): Do not attempt to shorten records

of secondary indexes.  (This is just an optimization; the logic in the
search loop would never store such records externally.)

data/data0data.c

@@ -488,7 +488,8 @@ dtuple_convert_big_rec(
 				/* out, own: created big record vector,
 				NULL if we are not able to shorten
 				the entry enough, i.e., if there are
-				too many short fields in entry */
+				too many fixed-length or short fields
+				in entry or the index is clustered */
 	dict_index_t*	index,	/* in: index */
 	dtuple_t*	entry,	/* in: index entry */
 	const ulint*	ext_vec,/* in: array of externally stored fields,
@@ -507,6 +508,10 @@ dtuple_convert_big_rec(
 	ulint		i;
 	ulint		j;
 
+	if (UNIV_UNLIKELY(!dict_index_is_clust(index))) {
+		return(NULL);
+	}
+
 	ut_a(dtuple_check_typed_no_assert(entry));
 
 	size = rec_get_converted_size(index, entry);

include/data0data.h

@@ -348,7 +348,8 @@ dtuple_convert_big_rec(
 				/* out, own: created big record vector,
 				NULL if we are not able to shorten
 				the entry enough, i.e., if there are
-				too many short fields in entry */
+				too many fixed-length or short fields
+				in entry or the index is clustered */
 	dict_index_t*	index,	/* in: index */
 	dtuple_t*	entry,	/* in: index entry */
 	const ulint*	ext_vec,/* in: array of externally stored fields,