Include TableFunc references when computing expression dependencies.

The TableFunc node (i.e., XMLTABLE) includes type and collation OIDs
that might not be referenced anywhere else in the expression tree,
so they need to be accounted for when extracting dependencies.

Fortunately, the practical effects of this are limited, since
(a) it's somewhat unlikely that people would be extracting
columns of non-builtin types from an XML document, and (b)
in many scenarios, the query would contain other references
to such types, or functions depending on them.  However, it's
not hard to construct examples wherein the existing code lets
one drop a type used in XMLTABLE and thereby break a view.

This is evidently an original oversight in the XMLTABLE patch,
so back-patch to v10 where that came in.

Discussion: https://postgr.es/m/18427.1573508501@sss.pgh.pa.us

diff --git a/src/backend/catalog/dependency.c b/src/backend/catalog/dependency.c
index 6bf6b60867b0a4c180b15b7495d75b739b51214e..d42951e293f034be285906f0bfe445120aef0068 100644 (file)
--- a/src/backend/catalog/dependency.c
+++ b/src/backend/catalog/dependency.c
@@ -2027,6 +2027,28 @@ find_expr_references_walker(Node *node,
                                   context->addrs);
        }
    }
+   else if (IsA(node, TableFunc))
+   {
+       TableFunc  *tf = (TableFunc *) node;
+       ListCell   *ct;
+
+       /*
+        * Add refs for the datatypes and collations used in the TableFunc.
+        */
+       foreach(ct, tf->coltypes)
+       {
+           add_object_address(OCLASS_TYPE, lfirst_oid(ct), 0,
+                              context->addrs);
+       }
+       foreach(ct, tf->colcollations)
+       {
+           Oid         collid = lfirst_oid(ct);
+
+           if (OidIsValid(collid) && collid != DEFAULT_COLLATION_OID)
+               add_object_address(OCLASS_COLLATION, collid, 0,
+                                  context->addrs);
+       }
+   }
    else if (IsA(node, TableSampleClause))
    {
        TableSampleClause *tsc = (TableSampleClause *) node;