Disallow ALTER DOMAIN on non-domain type everywhere

This has been the behavior already in most cases, but through
omission, ALTER DOMAIN / OWNER TO and ALTER DOMAIN / SET SCHEMA would
silently work on non-domain types as well.

src/backend/commands/alter.c

@@ -213,7 +213,7 @@ ExecAlterObjectSchemaStmt(AlterObjectSchemaStmt *stmt)
 
 		case OBJECT_TYPE:
 		case OBJECT_DOMAIN:
-			AlterTypeNamespace(stmt->object, stmt->newschema);
+			AlterTypeNamespace(stmt->object, stmt->newschema, stmt->objectType);
 			break;
 
 		default:
@@ -510,7 +510,7 @@ ExecAlterOwnerStmt(AlterOwnerStmt *stmt)
 
 		case OBJECT_TYPE:
 		case OBJECT_DOMAIN:		/* same as TYPE */
-			AlterTypeOwner(stmt->object, newowner);
+			AlterTypeOwner(stmt->object, newowner, stmt->objectType);
 			break;
 
 		case OBJECT_TSDICTIONARY:

src/backend/commands/typecmds.c

@@ -3165,7 +3165,7 @@ RenameType(RenameStmt *stmt)
  * Change the owner of a type.
  */
 void
-AlterTypeOwner(List *names, Oid newOwnerId)
+AlterTypeOwner(List *names, Oid newOwnerId, ObjectType objecttype)
 {
 	TypeName   *typename;
 	Oid			typeOid;
@@ -3195,6 +3195,13 @@ AlterTypeOwner(List *names, Oid newOwnerId)
 	tup = newtup;
 	typTup = (Form_pg_type) GETSTRUCT(tup);
 
+	/* Don't allow ALTER DOMAIN on a type */
+	if (objecttype == OBJECT_DOMAIN && typTup->typtype != TYPTYPE_DOMAIN)
+		ereport(ERROR,
+				(errcode(ERRCODE_WRONG_OBJECT_TYPE),
+				 errmsg("%s is not a domain",
+						format_type_be(typeOid))));
+
 	/*
 	 * If it's a composite type, we need to check that it really is a
 	 * free-standing composite type, and not a table's rowtype. We want people
@@ -3328,7 +3335,7 @@ AlterTypeOwnerInternal(Oid typeOid, Oid newOwnerId,
  * Execute ALTER TYPE SET SCHEMA
  */
 void
-AlterTypeNamespace(List *names, const char *newschema)
+AlterTypeNamespace(List *names, const char *newschema, ObjectType objecttype)
 {
 	TypeName   *typename;
 	Oid			typeOid;
@@ -3338,6 +3345,13 @@ AlterTypeNamespace(List *names, const char *newschema)
 	typename = makeTypeNameFromNameList(names);
 	typeOid = typenameTypeId(NULL, typename);
 
+	/* Don't allow ALTER DOMAIN on a type */
+	if (objecttype == OBJECT_DOMAIN && get_typtype(typeOid) != TYPTYPE_DOMAIN)
+		ereport(ERROR,
+				(errcode(ERRCODE_WRONG_OBJECT_TYPE),
+				 errmsg("%s is not a domain",
+						format_type_be(typeOid))));
+
 	/* get schema OID and check its permissions */
 	nspOid = LookupCreationNamespace(newschema);
 

src/include/commands/typecmds.h

@@ -38,10 +38,10 @@ extern void AlterDomainDropConstraint(List *names, const char *constrName,
 extern List *GetDomainConstraints(Oid typeOid);
 
 extern void RenameType(RenameStmt *stmt);
-extern void AlterTypeOwner(List *names, Oid newOwnerId);
+extern void AlterTypeOwner(List *names, Oid newOwnerId, ObjectType objecttype);
 extern void AlterTypeOwnerInternal(Oid typeOid, Oid newOwnerId,
 					   bool hasDependEntry);
-extern void AlterTypeNamespace(List *names, const char *newschema);
+extern void AlterTypeNamespace(List *names, const char *newschema, ObjectType objecttype);
 extern Oid	AlterTypeNamespace_oid(Oid typeOid, Oid nspOid);
 extern Oid AlterTypeNamespaceInternal(Oid typeOid, Oid nspOid,
 						   bool isImplicitArray,