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 b084584f6f1e1bd32f3c9d6a554d607807768e4a..3a729ed880bb11ee3f84566cb69afb1581b1739d 100644 (file)
--- a/src/backend/access/index/genam.c
+++ b/src/backend/access/index/genam.c
@@ -206,10 +206,15 @@ 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);