Fix BuildIndexValueDescription for expressions

In 804b6b6db4dcfc590a468e7be390738f9f7755fb we modified
BuildIndexValueDescription to pay attention to which columns are visible
to the user, but unfortunatley that commit neglected to consider indexes
which are built on expressions.

Handle error-reporting of violations of constraint indexes based on
expressions by not returning any detail when the user does not have
table-level SELECT rights.

Backpatch to 9.0, as the prior commit was.

Pointed out by Tom.

diff --git a/src/backend/access/index/genam.c b/src/backend/access/index/genam.c
index 014823a3d73c3c5610b4a969ab2a3bd54adbafb9..87e6f17d44362e5ea3af980239771199052d498d 100644 (file)
--- a/src/backend/access/index/genam.c
+++ b/src/backend/access/index/genam.c
@@ -208,10 +208,15 @@ BuildIndexValueDescription(Relation indexRelation,
                {
                        AttrNumber      attnum = idxrec->indkey.values[keyno];
 
-                       aclresult = pg_attribute_aclcheck(indrelid, attnum, GetUserId(),
-                                                                                         ACL_SELECT);
-
-                       if (aclresult != ACLCHECK_OK)
+                       /*
+                        * Note that if attnum == InvalidAttrNumber, then this is an
+                        * index based on an expression and we return no detail rather
+                        * than try to figure out what column(s) the expression includes
+                        * and if the user has SELECT rights on them.
+                        */
+                       if (attnum == InvalidAttrNumber ||
+                               pg_attribute_aclcheck(indrelid, attnum, GetUserId(),
+                                                                         ACL_SELECT) != ACLCHECK_OK)
                        {
                                /* No access, so clean up and return */
                                ReleaseSysCache(ht_idx);