If res is a GSimpleAsyncResult, this is equivalent to
g_simple_async_result_propagate_error(). Otherwise it returns
FALSE.
This can be used for legacy error handling in async
_finish() wrapper functions that traditionally
handled GSimpleAsyncResult error returns themselves rather than
calling into the virtual method. This should not be used in new
code; GAsyncResult errors that are set by virtual methods should
also be extracted by virtual methods, to enable subclasses to chain
up correctly.
Since 2.34
If res is a GSimpleAsyncResult, this is equivalent to g_simple_async_result_propagate_error(). Otherwise it returns FALSE. This can be used for legacy error handling in async _finish() wrapper functions that traditionally handled GSimpleAsyncResult error returns themselves rather than calling into the virtual method. This should not be used in new code; GAsyncResult errors that are set by virtual methods should also be extracted by virtual methods, to enable subclasses to chain up correctly. Since 2.34