CString doesn't need the varlena header space
CString only has the length and data in the serialized structure, no
need to allocate spaces for the varlena header.
@@ -810,7 +810,7 @@ DeserializeTuple(SerTupInfo *pSerInfo, StringInfo serialTup)
if (sz < 0)
elog(ERROR, "invalid length received for a CString");
- p = palloc(sz + VARHDRSZ);
+ p = palloc(sz);
/* Then data */
pq_copymsgbytes(serialTup, p, sz);
