pidgin/pidgin

Fix incompatible type conversion errors
release-2.x.y
3 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/
#ifndef DBUS_API_SUBJECT_TO_CHANGE
#define DBUS_API_SUBJECT_TO_CHANGE
#endif
#include <stdio.h>
#include <stdlib.h>
#include "purple-client.h"
/*
This example demonstrates how to use libpurple-client to communicate
with purple. The names and signatures of functions provided by
libpurple-client are the same as those in purple. However, all
structures (such as PurpleAccount) are opaque, that is, you can only
use pointer to them. In fact, these pointers DO NOT actually point
to anything, they are just integer identifiers of assigned to these
structures by purple. So NEVER try to dereference these pointers.
Integer ids as disguised as pointers to provide type checking and
prevent mistakes such as passing an id of PurpleAccount when an id of
PurpleBuddy is expected. According to glib manual, this technique is
portable.
*/
int main (int argc, char **argv)
{
GList *alist, *node;
purple_init();
alist = purple_accounts_get_all();
for (node = alist; node != NULL; node = node->next)
{
PurpleAccount *account = (PurpleAccount*) node->data;
char *name = purple_account_get_username(account);
g_print("Name: %s\n", name);
g_free(name);
}
g_list_free(alist);
return 0;
}