Add support for functions with multiple delegate parameters and only one data parameter
Submitted by Julian Andres Klode
Link to original bug (#602712)
Description
libarchive has functions like "int archive_read_open(struct archive *, void *_client_data, archive_open_callback *, archive_read_callback *, archive_close_callback *);".
which is bound as public Result open ( [CCode (delegate_target_pos = 0.9)] OpenCallback ocb, [CCode (delegate_target_pos = 0.9)] ReadCallback rcb, [CCode (delegate_target_pos = 0.9)] CloseCallback ccb );
But this only works if all delegate parameters have the same state; because Vala will pass the data for the latest callback.