Is the given *properties* iterator pointing at a valid (key,value)
pair.
When this function returns TRUE,
notmuch_message_properties_{key,value} will return a valid string,
and notmuch_message_properties_move_to_next will do what it
says. Whereas when this function returns FALSE, calling any of
these functions results in undefined behaviour.
See the documentation of notmuch_message_properties_get for example
code showing how to iterate over a notmuch_message_properties_t
object.
Is the given *properties* iterator pointing at a valid (key,value) pair.
When this function returns TRUE, notmuch_message_properties_{key,value} will return a valid string, and notmuch_message_properties_move_to_next will do what it says. Whereas when this function returns FALSE, calling any of these functions results in undefined behaviour.
See the documentation of notmuch_message_properties_get for example code showing how to iterate over a notmuch_message_properties_t object.
@since libnotmuch 4.4 (notmuch 0.23)