qom: Clean up object_property_get_enum()'s error value

object_property_get_enum() is the only object_property_FOO() that is
documented to return an undefined value on error.  It does no such
thing, actually: it returns 0 on some errors, and -1 on others.

Needlessly complicated.  Always return -1 on error, and adjust the
contract.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Greg Kurz <groug@kaod.org>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Message-Id: <20200917125540.597786-2-armbru@redhat.com>
Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>

1 files changed, 3 insertions, 3 deletions

diff --git a/include/qom/object.h b/include/qom/object.h
index 6c0d424..494827b 100644
--- a/include/qom/object.h
+++ b/include/qom/object.h
@@ -1687,9 +1687,9 @@ uint64_t object_property_get_uint(Object *obj, const char *name,
  * @typename: the name of the enum data type
  * @errp: returns an error if this function fails
  *
- * Returns: the value of the property, converted to an integer, or
- * undefined if an error occurs (including when the property value is not
- * an enum).
+ * Returns: the value of the property, converted to an integer (which
+ * can't be negative), or -1 on error (including when the property
+ * value is not an enum).
  */
 int object_property_get_enum(Object *obj, const char *name,
                              const char *typename, Error **errp);