glib: Document G_IO_ERROR as a possible error condition

This was already implicit from G_IO_ERROR_NOT_SUPPORTED being a
documented error condition, and from the use of GCancellable, but is
probably clearer when spelled out explicitly. The addition of
g_seekable_seek() and g_seekable_tell() in the previous commit might
add more error conditions in the same domain.

Signed-off-by: Simon McVittie <>
1 file changed