Use generic helpers for obtaining file attributes
It is not guaranteed that all GFileInfo attributes are always set when
requested. They used to be silently set to NULL, FALSE, or 0 earlier
when they were not provided by their implementations. However, some of the
helper functions now print critical errors when the attributes are not set
by their implementations even though they were requested. See the
glib!3261 (merged) merge request for
more details. So Nautilus now prints tons of critical errors when started.
The unset attributes can be detected over the g_file_info_has_attribute
function. But Nautilus doesn't care in most cases about the reason why the
attribute is NULL, FALSE, or 0. There are also more generic helper
functions that don't print these critical errors. Let's use them for the
attributes that may not always be set to get rid of those critical errors.
I suppose that the name, display_name, size, icon, and file_type
attributes don't need this special handling, although it is not clearly
stated anywhere...
Fixes: #2861 (closed)