gst.wasm: fix g_list_deep_copy GCopyFunc signature mismatch

[aslobodeniuk]

No description provided.

[rgonzalezfluendo]

This PR must point to a feature branch of https://github.com/fluendo/gst.wasm/blob/main/guw/gstreamer.gst.wasm.toml

[cfoch]

This should target wasm-main-function-pointer, IMO

[cfoch]

What do you think about creating a function in gstcontext.c/.h named gst_context_ref_with_data?

[aslobodeniuk]

Ready to agree with any of the ways, but I think this might bring problems at the moment of upstreaming, since it would be a new API, and new API also needs documentation, bindings generated, etc.
Maybe we could create a private header like gstemscripten.h or put into gstcompat.h macro like

#define GST_GCOPY(func) gst_gcopy_with_##func

#define GST_DEFINE_GCOPY_WITH(func)  \
static gpointer                                                 \
gst_gcopy_with_##func (gconstpointer src, gpointer data) {  \
  return func (src);                                                                            \
}

GST_DEFINE_GCOPY(gst_context_ref);
GST_DEFINE_GCOPY(gst_buffer_ref);
GST_DEFINE_GCOPY(g_strdup);
...

so the code in this file would be

ret = g_list_copy_deep (element->contexts, GST_GCOPY(gst_context_ref), NULL);

[cfoch]

I like the idea (cc @turran). Should we do it on this PR, @aslobodeniuk ?

[cfoch]

I think not here, otherwise we have to fix several stuff. So I just approve.

[cfoch]

Wrong target branch. Watch out!