Fix bogus rec_get_offsets() debug assertion failures for ROW_FORMAT=REDUNDANT

When the debug parameter 'bool leaf' was added to rec_get_offsets(),
also some debug assertions for reading the heap_no of ROW_FORMAT=REDUNDANT
records were added. However, the heap number is uninitialized when
offsets are being computed for to-be-inserted records.

For debug builds, initialize the heap number to a dummy value, so that
the record will be interpreted as 'user record'. The infimum and supremum
pseudo-records are never copied from the page frame and never inserted;
they are part of the page creation.

rec_convert_dtuple_to_rec_old(): Remove a bogus memset() in debug builds.

storage/innobase/page/page0cur.cc

@@ -1176,9 +1176,15 @@ page_cur_parse_insert_rec(
 	ut_memcpy(buf + mismatch_index, ptr, end_seg_len);
 
 	if (page_is_comp(page)) {
+		/* Make rec_get_offsets() and rec_offs_make_valid() happy. */
+		ut_d(rec_set_heap_no_new(buf + origin_offset,
+					 PAGE_HEAP_NO_USER_LOW));
 		rec_set_info_and_status_bits(buf + origin_offset,
 					     info_and_status_bits);
 	} else {
+		/* Make rec_get_offsets() and rec_offs_make_valid() happy. */
+		ut_d(rec_set_heap_no_old(buf + origin_offset,
+					 PAGE_HEAP_NO_USER_LOW));
 		rec_set_info_bits_old(buf + origin_offset,
 				      info_and_status_bits);
 	}

storage/innobase/rem/rem0rec.cc

@@ -1130,17 +1130,14 @@ rec_convert_dtuple_to_rec_old(
 	/* Calculate the offset of the origin in the physical record */
 
 	rec = buf + rec_get_converted_extra_size(data_size, n_fields, n_ext);
-#ifdef UNIV_DEBUG
-	/* Suppress Valgrind warnings of ut_ad()
-	in mach_write_to_1(), mach_write_to_2() et al. */
-	memset(buf, 0xff, rec - buf + data_size);
-#endif /* UNIV_DEBUG */
 	/* Store the number of fields */
 	rec_set_n_fields_old(rec, n_fields);
 
 	/* Set the info bits of the record */
 	rec_set_info_bits_old(rec, dtuple_get_info_bits(dtuple)
 			      & REC_INFO_BITS_MASK);
+	/* Make rec_get_offsets() and rec_offs_make_valid() happy. */
+	ut_d(rec_set_heap_no_old(rec, PAGE_HEAP_NO_USER_LOW));
 
 	/* Store the data and the offsets */
 
@@ -1254,6 +1251,8 @@ rec_convert_dtuple_to_rec_comp(
 			temp = false;
 		}
 	} else {
+		/* Make rec_get_offsets() and rec_offs_make_valid() happy. */
+		ut_d(rec_set_heap_no_new(rec, PAGE_HEAP_NO_USER_LOW));
 		nulls = rec - (REC_N_NEW_EXTRA_BYTES + 1);
 
 		switch (UNIV_EXPECT(status, REC_STATUS_ORDINARY)) {