Re: BUG #5111: Segmentation fault, if to_tsvector returns empty row to ts_stat

"Fendris" <f(dot)fendris(at)gmail(dot)com> writes:
> SELECT * from ts_stat('SELECT to_tsvector(''simple'','''')');
> [ dumps core ]

Thanks, looks like this code just missed the possibility of an empty
tree. Attached patch fixes it.

regards, tom lane

*** src/backend/utils/adt/tsvector_op.c.orig Thu Jul 16 02:33:44 2009
--- src/backend/utils/adt/tsvector_op.c Tue Oct 13 10:19:24 2009
***************
*** 959,975 ****

node = stat->root;
/* find leftmost value */
! for (;;)
! {
! stat->stack[stat->stackpos] = node;
! if (node->left)
{
! stat->stackpos++;
! node = node->left;
}
! else
! break;
! }

tupdesc = CreateTemplateTupleDesc(3, false);
TupleDescInitEntry(tupdesc, (AttrNumber) 1, "word",
--- 959,979 ----

node = stat->root;
/* find leftmost value */
! if (node == NULL)
! stat->stack[stat->stackpos] = NULL;
! else
! for (;;)
{
! stat->stack[stat->stackpos] = node;
! if (node->left)
! {
! stat->stackpos++;
! node = node->left;
! }
! else
! break;
}
! Assert(stat->stackpos <= stat->maxdepth);

tupdesc = CreateTemplateTupleDesc(3, false);
TupleDescInitEntry(tupdesc, (AttrNumber) 1, "word",
***************
*** 1015,1020 ****
--- 1019,1025 ----
else
break;
}
+ Assert(stat->stackpos <= stat->maxdepth);
}
else
{