Fix crasher bugs in previous commit

ALTER DEFAULT PRIVILEGES was trying to decode the list of roles in the
FOR clause as a list of names rather than of RoleSpecs; and the IN
clause in CREATE ROLE was doing the same thing.  This was evidenced by
crashes on some buildfarm machines, though on my platform this doesn't
cause a failure by mere chance; I can reproduce the failures only by
adding some padding in struct RoleSpecs.

Fix by dereferencing those lists as being of RoleSpecs, not string
Values.

1 files changed, 6 insertions, 2 deletions

diff --git a/src/backend/commands/user.c b/src/backend/commands/user.c
index c14465eb87b..75f1b3cd4f2 100644
--- a/src/backend/commands/user.c
+++ b/src/backend/commands/user.c
@@ -429,13 +429,17 @@ CreateRole(CreateRoleStmt *stmt)
 	 */
 	foreach(item, addroleto)
 	{
-		char	   *oldrolename = strVal(lfirst(item));
-		Oid			oldroleid = get_role_oid(oldrolename, false);
+		RoleSpec   *oldrole = lfirst(item);
+		HeapTuple	oldroletup = get_rolespec_tuple((Node *) oldrole);
+		Oid			oldroleid = HeapTupleGetOid(oldroletup);
+		char	   *oldrolename = NameStr(((Form_pg_authid) GETSTRUCT(oldroletup))->rolname);
 
 		AddRoleMems(oldrolename, oldroleid,
 					list_make1(makeString(stmt->role)),
 					list_make1_oid(roleid),
 					GetUserId(), false);
+
+		ReleaseSysCache(oldroletup);
 	}
 
 	/*