Downgrade error in object_aclmask_ext() to internal

The "does not exist" error in object_aclmask_ext() was written as
ereport(), suggesting that it is user-facing.  This is problematic:
get_object_class_descr() is meant to be for internal errors only and
does not support translation.

For the has_xxx_privilege functions, the error has not been
user-facing since commit 403ac226ddd.  The remaining users are
pg_database_size() and pg_tablespace_size().  The call stack here is
pretty deep and this dependency is not obvious.  Here we can put in an
explicit existence check with a bespoke error message early in the
function.

Then we can downgrade the error in object_aclmask_ext() to a normal
"cache lookup failed" internal error.

Reviewed-by: Alvaro Herrera <alvherre@alvh.no-ip.org>
Discussion: https://www.postgresql.org/message-id/flat/da2f8942-be6d-48d0-ac1c-a053370a6b1f@eisentraut.org

diff --git a/src/backend/catalog/aclchk.c b/src/backend/catalog/aclchk.c
index bd006931938ff4a53119fd32cfb752101e0a1247..02a754cc30a70cbb991620036c80dd2a1a923e0e 100644 (file)
--- a/src/backend/catalog/aclchk.c
+++ b/src/backend/catalog/aclchk.c
@@ -3004,10 +3004,6 @@ pg_aclmask(ObjectType objtype, Oid object_oid, AttrNumber attnum, Oid roleid,
  * Exported routines for examining a user's privileges for various objects
  *
  * See aclmask() for a description of the common API for these functions.
- *
- * Note: we give lookup failure the full ereport treatment because the
- * has_xxx_privilege() family of functions allow users to pass any random
- * OID to these functions.
  * ****************************************************************
  */
 
@@ -3074,10 +3070,8 @@ object_aclmask_ext(Oid classid, Oid objectid, Oid roleid,
            return 0;
        }
        else
-           ereport(ERROR,
-                   (errcode(ERRCODE_UNDEFINED_OBJECT),
-                    errmsg("%s with OID %u does not exist",
-                           get_object_class_descr(classid), objectid)));
+           elog(ERROR, "cache lookup failed for %s %u",
+                get_object_class_descr(classid), objectid);
    }
 
    ownerId = DatumGetObjectId(SysCacheGetAttrNotNull(cacheid,

diff --git a/src/backend/utils/adt/dbsize.c b/src/backend/utils/adt/dbsize.c
index e560fef69196178e5c8d17586545de59f267363c..011d8d4da5aaaee8a310694c1cbaad0d5ee2553e 100644 (file)
--- a/src/backend/utils/adt/dbsize.c
+++ b/src/backend/utils/adt/dbsize.c
@@ -170,6 +170,15 @@ pg_database_size_oid(PG_FUNCTION_ARGS)
    Oid         dbOid = PG_GETARG_OID(0);
    int64       size;
 
+   /*
+    * Not needed for correctness, but avoid non-user-facing error message
+    * later if the database doesn't exist.
+    */
+   if (!SearchSysCacheExists1(DATABASEOID, ObjectIdGetDatum(dbOid)))
+       ereport(ERROR,
+               errcode(ERRCODE_UNDEFINED_OBJECT),
+               errmsg("database with OID %u does not exist", dbOid));
+
    size = calculate_database_size(dbOid);
 
    if (size == 0)
@@ -274,6 +283,15 @@ pg_tablespace_size_oid(PG_FUNCTION_ARGS)
    Oid         tblspcOid = PG_GETARG_OID(0);
    int64       size;
 
+   /*
+    * Not needed for correctness, but avoid non-user-facing error message
+    * later if the tablespace doesn't exist.
+    */
+   if (!SearchSysCacheExists1(TABLESPACEOID, ObjectIdGetDatum(tblspcOid)))
+       ereport(ERROR,
+               errcode(ERRCODE_UNDEFINED_OBJECT),
+               errmsg("tablespace with OID %u does not exist", tblspcOid));
+
    size = calculate_tablespace_size(tblspcOid);
 
    if (size < 0)