[PATCH][BUG_FIX] Potential null pointer dereferencing.

[Ranier Vilela]

Hi,
ExecClearTuple don't check por NULL pointer arg and according
TupIsNull slot can be NULL.

Can anyone check this buf fix?

--- \dll\postgresql-12.0\a\backend\executor\nodeUnique.c        Mon Sep 30 
17:06:55 2019
+++ nodeUnique.c        Tue Nov 12 09:54:34 2019
@@ -74,7 +74,8 @@
                if (TupIsNull(slot))
                {
                        /* end of subplan, so we're done */
-                       ExecClearTuple(resultTupleSlot);
+                   if (!TupIsNull(resultTupleSlot))
+                           ExecClearTuple(resultTupleSlot);
                        return NULL;
                }
 

nodeUnique.c.patch
Description: nodeUnique.c.patch