pidgin/pidgin

Fix incompatible type conversion errors
release-2.x.y
4 months ago, Elliott Sales de Andrade
488055ab5531
Fix incompatible type conversion errors

- A recent libxml2 changed its handler function to take a `const` pointer. It's
safe for us to have it, and them not, but the opposite way causes an implicit
cast warning.
- In relatively new GLib (many years now), `g_object_ref` casts its output to
match its input. This means we should not be casting to `G_OBJECT`, as that
is not the type it expects, and would translate to the output being `GObject`
instead of the original type.

This fixes the build in Fedora 40, which changes several incompatible pointer
conversion warnings into errors.

This patch is partially from the Fedora maintainer @yarda, with some corrections by me (to the `g_object_ref` portions.)

Testing Done:
Compiled in a Rawhide environment with this patch applied.

Bugs closed: PIDGIN-17850

Reviewed at https://reviews.imfreedom.org/r/2944/
/** @page connection-signals Connection Signals
@signals
@signal signing-on
@signal signed-on
@signal autojoin
@signal signing-off
@signal signed-off
@signal connection-error
@endsignals
@see connection.h
<hr>
@signaldef signing-on
@signalproto
void (*signing_on)(PurpleConnection *gc);
@endsignalproto
@signaldesc
Emitted when a connection is about to sign on.
@param gc The connection that is about to sign on.
@endsignaldef
@signaldef signed-on
@signalproto
void (*signed_on)(PurpleConnection *gc);
@endsignalproto
@signaldesc
Emitted when a connection has signed on.
@param gc The connection that has signed on.
@endsignaldef
@signaldef autojoin
@signalproto
gboolean (*autojoin)(PurpleConnection *gc);
@endsignalproto
@signaldesc
Emitted when a connection has signed on, after the signed-on signal, to
signal UIs to autojoin chats if they wish. UIs should connect to this
with @c PURPLE_SIGNAL_PRIORITY_HIGHEST to allow plugins to block this
signal before the UI sees it and then re-emit it later.
@param gc The connection that has signed on.
@return @c TRUE if the signal was handled or @c FALSE otherwise. In
practice, the return value is irrelevant, as it really only
exists so plugins can block the UI's autojoin.
@since 2.7.0
@endsignaldef
@signaldef signing-off
@signalproto
void (*signing_off)(PurpleConnection *gc);
@endsignalproto
@signaldesc
Emitted when a connection is about to sign off.
@param gc The connection that is about to sign off.
@endsignaldef
@signaldef signed-off
@signalproto
void (*signed_off)(PurpleConnection *gc);
@endsignalproto
@signaldesc
Emitted when a connection has signed off.
@param gc The connection that has signed off.
@endsignaldef
@signaldef connection-error
@signalproto
void (*connection_error)(PurpleConnection *gc, PurpleConnectionError err, const gchar *desc)
@endsignalproto
@signaldesc
Emitted when a connection error occurs, before @ref signed-off.
@param gc The connection on which the error has occurred
@param err The error that occurred
@param desc A description of the error, giving more information.
@endsignaldef
*/
// vim: syntax=c.doxygen tw=75 et