Pointer is checked against null but then dereferenced anyway

Defect 114097 (STATIC_C)
Checker FORWARD_NULL (subcategory none)
File: /src/reconcile/rec_visibility.c
Function __rec_append_orig_value
/src/reconcile/rec_visibility.c, line: 79
Comparing "unpack" to null implies that "unpack" might be null.

            if (unpack != NULL && unpack->start_ts == upd->start_ts && unpack->start_txn == upd->txnid)

/src/reconcile/rec_visibility.c, line: 107
Dereferencing null pointer "unpack".

        if (unpack->stop_ts != WT_TS_MAX || unpack->stop_txn != WT_TXN_MAX) {