branches/zip: Minor cleanup.

dtuple_create(): Simplify a pointer expression.  Flag the fields uninitialized
after initializing them in the debug version.

dtuple_t: Only declare magic_n if UNIV_DEBUG is defined.  The field is
not assigned to nor tested unless UNIV_DEBUG is defined.

include/data0data.h

@@ -410,9 +410,11 @@ struct dtuple_struct {
 	UT_LIST_NODE_T(dtuple_t) tuple_list;
 					/* data tuples can be linked into a
 					list using this field */
+#ifdef UNIV_DEBUG
 	ulint		magic_n;
+# define		DATA_TUPLE_MAGIC_N	65478679
+#endif /* UNIV_DEBUG */
 };
-#define	DATA_TUPLE_MAGIC_N	65478679
 
 /* A slot for a field in a big rec vector */
 

include/data0data.ic

@@ -325,7 +325,7 @@ dtuple_create(
 	tuple->info_bits = 0;
 	tuple->n_fields = n_fields;
 	tuple->n_fields_cmp = n_fields;
-	tuple->fields = (dfield_t*)(((byte*)tuple) + sizeof(dtuple_t));
+	tuple->fields = (dfield_t*) &tuple[1];
 
 #ifdef UNIV_DEBUG
 	tuple->magic_n = DATA_TUPLE_MAGIC_N;
@@ -343,6 +343,8 @@ dtuple_create(
 			dfield_get_type(field)->mtype = DATA_ERROR;
 		}
 	}
+
+	UNIV_MEM_INVALID(tuple->fields, n_fields * sizeof *tuple->fields);
 #endif
 	return(tuple);
 }