XAR plugin format mojo sets the default language for a document if there is a page with the same name that has translations regardless of its space

xar:format has a feature to auto identify whether a page has translations and to set its default language (otherwise the default language is set to empty).
However, this feature has a bug and considers that a page has translations if there is a page with the same name in a different space that has translations.

For example, if you have, in the module's sources, Main/WebHome.fr.xml and TestSpace/WebHome.xml , the default language for TestSpace/WebHome.xml will be set by the xar format. If Main/WebHome.fr.xml is not present, the default language for TestSpace/WebHome.xml is not set.