Bug#996084: vte2.91: wrong argument list in spawn_async documentation

[Simon McVittie]

On Sun, 10 Oct 2021 at 23:07:35 +0200, Nis Martensen wrote:
> According to
> https://lazka.github.io/pgi-docs/Vte-2.91/classes/Terminal.html#Vte.Terminal.spawn_async
> and
> https://lazka.github.io/pgi-docs/#Vte-2.91/classes/Pty.html#Vte.Pty.spawn_async
> the order of arguments includes:
> ..., spawn_flags, child_setup, timeout, ...
> 
> However, the code does not work when trying to use that argument order,
> the result is: TypeError: Argument 9 does not allow None as a value
> 
> It would be great if the code and its documentation would match.

Debian does not maintain that documentation, and the representation of
C functions in PyGI is really a question for PyGI rather than the specific
C library whose API has been wrapped.

The signature of these functions in C is:

void vte_terminal_spawn_async(VteTerminal *terminal,
                              VtePtyFlags pty_flags,
                              const char *working_directory,
                              char **argv,
                              char **envv,
                              GSpawnFlags spawn_flags,
                              GSpawnChildSetupFunc child_setup,
                              gpointer child_setup_data,
                              GDestroyNotify child_setup_data_destroy,
                              int timeout,
                              GCancellable *cancellable,
                              VteTerminalSpawnAsyncCallback callback,
                              gpointer user_data) _VTE_CXX_NOEXCEPT _VTE_GNUC_NONNULL(1) _VTE_GNUC_NONNULL(4);
void vte_pty_spawn_async(VtePty *pty,
                         const char *working_directory,
                         char **argv,
                         char **envv,
                         GSpawnFlags spawn_flags,
                         GSpawnChildSetupFunc child_setup,
                         gpointer child_setup_data,
                         GDestroyNotify child_setup_data_destroy,
                         int timeout,
                         GCancellable *cancellable,
                         GAsyncReadyCallback callback,
                         gpointer user_data) _VTE_CXX_NOEXCEPT _VTE_GNUC_NONNULL(1) _VTE_GNUC_NONNULL(3);

and you can find the GObject-Introspection representation of them in
/usr/share/gir-1.0/Vte-2.91.gir.

It looks as though whatever software generated
https://lazka.github.io/pgi-docs/Vte-2.91 is assuming that the
(child_setup, child_setup_data, child_setup_data_destroy) group
will come out in PyGI as a single argument, child_setup.

However, from the stackoverflow question, it looks like child_setup
and child_setup_data turn into separate arguments in Python, with
only child_setup_data_destroy disappearing.

This seems like a bug in the documentation-generating tool.

    smcv