Remove C99-obsoleted constructs

See [this development thread for a future Fedora change](https://lists.fedoraproject.org/archives/list/devel@lists.fedoraproject.org/thread/CJXKTLXJUPZ4F2C2VQOTNMEA5JAUPMBD/) or [the proposed change page](https://fedoraproject.org/wiki/Changes/PortingToModernC). These may be made stronger errors in GCC 14.

Testing Done:
Configured with `-Dc_args='-Werror=implicit-int -Werror=implicit-function-declaration -Werror=int-conversion -Werror=strict-prototypes -Werror=old-style-definition'` and compiled.

Reviewed at https://reviews.imfreedom.org/r/1974/

12 files changed, 60 insertions, 31 deletions

diff --git a/finch/gntaccount.c b/finch/gntaccount.c
index fd2ae3db80..5a40074bd2 100644
--- a/finch/gntaccount.c
+++ b/finch/gntaccount.c
@@ -781,7 +781,8 @@ reset_accounts_win(GntWidget *widget, gpointer null)
 	accounts.tree = NULL;
 }
 
-void finch_accounts_show_all()
+void
+finch_accounts_show_all(void)
 {
 	PurpleAccountManager *manager = NULL;
 	GList *iter;
@@ -889,7 +890,8 @@ account_abled_cb(PurpleAccount *account, gpointer user_data)
 			GPOINTER_TO_INT(user_data));
 }
 
-void finch_accounts_init()
+void
+finch_accounts_init(void)
 {
 	PurpleAccountManager *manager = NULL;
 	gpointer account_handle = NULL;
@@ -923,7 +925,8 @@ void finch_accounts_init()
 	}
 }
 
-void finch_accounts_uninit()
+void
+finch_accounts_uninit(void)
 {
 	if (accounts.window)
 		gnt_widget_destroy(accounts.window);
diff --git a/finch/gntblist.c b/finch/gntblist.c
index f3cbdb9d8f..e6b6c0f300 100644
--- a/finch/gntblist.c
+++ b/finch/gntblist.c
@@ -1951,7 +1951,8 @@ redraw_blist(const char *name, PurplePrefType type, gconstpointer val, gpointer
 	draw_tooltip(ggblist);
 }
 
-void finch_blist_init()
+void
+finch_blist_init(void)
 {
 	color_available = gnt_style_get_color(NULL, "color-available");
 	if (!color_available)
@@ -2795,7 +2796,8 @@ create_menu(void)
 	gnt_menu_add_item(GNT_MENU(menu), ggblist->plugins);
 }
 
-void finch_blist_show()
+void
+finch_blist_show(void)
 {
 	blist_show(purple_blist_get_default());
 }
@@ -2892,7 +2894,8 @@ blist_show(PurpleBuddyList *list)
 	savedstatus_changed(purple_savedstatus_get_current(), NULL);
 }
 
-void finch_blist_uninit()
+void
+finch_blist_uninit(void)
 {
 }
 
diff --git a/finch/gntconn.c b/finch/gntconn.c
index 76ce20d5db..f8127c321e 100644
--- a/finch/gntconn.c
+++ b/finch/gntconn.c
@@ -118,12 +118,14 @@ static PurpleConnectionUiOps ops = {
 	.report_disconnect = finch_connection_report_disconnect,
 };
 
-PurpleConnectionUiOps *finch_connections_get_ui_ops()
+PurpleConnectionUiOps *
+finch_connections_get_ui_ops(void)
 {
 	return &ops;
 }
 
-void finch_connections_init()
+void
+finch_connections_init(void)
 {
 	PurpleAccountManager *manager = purple_account_manager_get_default();
 
@@ -134,7 +136,8 @@ void finch_connections_init()
 	g_signal_connect(manager, "removed", G_CALLBACK(account_removed_cb), NULL);
 }
 
-void finch_connections_uninit()
+void
+finch_connections_uninit(void)
 {
 	PurpleAccountManager *manager = purple_account_manager_get_default();
 
diff --git a/finch/gntconv.c b/finch/gntconv.c
index 8065a93ee8..40da2b145c 100644
--- a/finch/gntconv.c
+++ b/finch/gntconv.c
@@ -1081,7 +1081,8 @@ static PurpleConversationUiOps conv_ui_ops = {
 	.has_focus = finch_conv_has_focus,
 };
 
-PurpleConversationUiOps *finch_conv_get_ui_ops()
+PurpleConversationUiOps *
+finch_conv_get_ui_ops(void)
 {
 	return &conv_ui_ops;
 }
@@ -1276,7 +1277,8 @@ users_command_cb(PurpleConversation *conv, const char *cmd, char **args, char **
 	return PURPLE_CMD_RET_OK;
 }
 
-void finch_conversation_init()
+void
+finch_conversation_init(void)
 {
 	color_message_send = gnt_style_get_color(NULL, "color-message-sent");
 	if (!color_message_send)
@@ -1383,7 +1385,8 @@ void finch_conversation_init()
 					G_CALLBACK(account_signing_off), NULL);
 }
 
-void finch_conversation_uninit()
+void
+finch_conversation_uninit(void)
 {
 	purple_signals_disconnect_by_handle(finch_conv_get_handle());
 }
diff --git a/finch/gntdebug.c b/finch/gntdebug.c
index 1ce01b3dde..03c1f4028c 100644
--- a/finch/gntdebug.c
+++ b/finch/gntdebug.c
@@ -262,7 +262,8 @@ save_debug_win(GntWidget *w, GntTextView *tv)
 	gnt_widget_show(window);
 }
 
-void finch_debug_window_show()
+void
+finch_debug_window_show(void)
 {
 	GntWidget *wid, *box, *label;
 
diff --git a/finch/gntnotify.c b/finch/gntnotify.c
index 429060c8ff..b13eea4724 100644
--- a/finch/gntnotify.c
+++ b/finch/gntnotify.c
@@ -406,17 +406,20 @@ static PurpleNotifyUiOps ops = {
 	.close_notify = finch_close_notify,
 };
 
-PurpleNotifyUiOps *finch_notify_get_ui_ops()
+PurpleNotifyUiOps *
+finch_notify_get_ui_ops(void)
 {
 	return &ops;
 }
 
-void finch_notify_init()
+void
+finch_notify_init(void)
 {
 	userinfo = g_hash_table_new_full(g_str_hash, g_str_equal, g_free, NULL);
 }
 
-void finch_notify_uninit()
+void
+finch_notify_uninit(void)
 {
 	g_hash_table_destroy(userinfo);
 }
diff --git a/finch/gntprefs.c b/finch/gntprefs.c
index efd9f1b037..0ca2011b6f 100644
--- a/finch/gntprefs.c
+++ b/finch/gntprefs.c
@@ -38,7 +38,8 @@ static struct {
 	GntWidget *window;
 } pref_request;
 
-void finch_prefs_init()
+void
+finch_prefs_init(void)
 {
 	purple_prefs_add_none("/finch");
 
@@ -55,7 +56,8 @@ void finch_prefs_init()
 	purple_prefs_add_path("/finch/filelocations/last_save_folder", "");
 }
 
-void finch_prefs_update_old()
+void
+finch_prefs_update_old(void)
 {
 }
 
@@ -251,7 +253,8 @@ add_pref_group(PurpleRequestFields *fields, const char *title, Prefs *prefs)
 	}
 }
 
-void finch_prefs_show_all()
+void
+finch_prefs_show_all(void)
 {
 	PurpleRequestFields *fields;
 
diff --git a/finch/gntrequest.c b/finch/gntrequest.c
index 10f1de7d1d..6de18210f4 100644
--- a/finch/gntrequest.c
+++ b/finch/gntrequest.c
@@ -821,16 +821,19 @@ static PurpleRequestUiOps uiops = {
 	.close_request = finch_close_request,
 };
 
-PurpleRequestUiOps *finch_request_get_ui_ops()
+PurpleRequestUiOps *
+finch_request_get_ui_ops(void)
 {
 	return &uiops;
 }
 
-void finch_request_init()
+void
+finch_request_init(void)
 {
 }
 
-void finch_request_uninit()
+void
+finch_request_uninit(void)
 {
 }
 
diff --git a/finch/gntstatus.c b/finch/gntstatus.c
index e43bed3f42..cd5cf95444 100644
--- a/finch/gntstatus.c
+++ b/finch/gntstatus.c
@@ -149,7 +149,8 @@ edit_savedstatus_cb(GntWidget *widget, gpointer null)
 	finch_savedstatus_edit(gnt_tree_get_selection_data(GNT_TREE(statuses.tree)));
 }
 
-void finch_savedstatus_show_all()
+void
+finch_savedstatus_show_all(void)
 {
 	GntWidget *window, *tree, *box, *button;
 	int widths[] = {25, 12, 35};
diff --git a/finch/gntui.c b/finch/gntui.c
index 32f2a6fc15..f0f15a1563 100644
--- a/finch/gntui.c
+++ b/finch/gntui.c
@@ -74,7 +74,8 @@ finch_history_init(GError **error) {
 	return purple_history_manager_set_active(manager, id, error);
 }
 
-void finch_ui_init()
+void
+finch_ui_init(void)
 {
 	GError *error = NULL;
 
@@ -143,7 +144,8 @@ void finch_ui_init()
 #ifdef STANDALONE
 }
 
-void finch_ui_uninit()
+void
+finch_ui_uninit(void)
 {
 	purple_accounts_set_ui_ops(NULL);
 	finch_accounts_uninit();
diff --git a/finch/gntxfer.c b/finch/gntxfer.c
index 31156d09de..b640f70ad2 100644
--- a/finch/gntxfer.c
+++ b/finch/gntxfer.c
@@ -254,7 +254,7 @@ finch_xfer_dialog_new(void)
 }
 
 void
-finch_xfer_dialog_destroy()
+finch_xfer_dialog_destroy(void)
 {
 	gnt_widget_destroy(xfer_dialog->window);
 	g_free(xfer_dialog);
@@ -262,7 +262,7 @@ finch_xfer_dialog_destroy()
 }
 
 void
-finch_xfer_dialog_show()
+finch_xfer_dialog_show(void)
 {
 	if (xfer_dialog == NULL)
 		finch_xfer_dialog_new();
diff --git a/finch/plugins/grouping/grouping.c b/finch/plugins/grouping/grouping.c
index 689ee0f06a..219710490b 100644
--- a/finch/plugins/grouping/grouping.c
+++ b/finch/plugins/grouping/grouping.c
@@ -66,7 +66,8 @@ G_DEFINE_DYNAMIC_TYPE(FinchGroupingNode, finch_grouping_node,
  */
 static FinchGroupingNode *online, *offline;
 
-static gboolean on_offline_init()
+static gboolean
+on_offline_init(void)
 {
 	GntTree *tree = finch_blist_get_tree();
 
@@ -151,7 +152,8 @@ static FinchBlistManager on_offline =
  * Meebo-like Grouping.
  */
 static FinchGroupingNode meebo;
-static gboolean meebo_init()
+static gboolean
+meebo_init(void)
 {
 	GntTree *tree = finch_blist_get_tree();
 	if (!g_list_find(gnt_tree_get_rows(tree), &meebo)) {
@@ -187,14 +189,16 @@ static FinchBlistManager meebo_group =
 /**
  * No Grouping.
  */
-static gboolean no_group_init()
+static gboolean
+no_group_init(void)
 {
 	GntTree *tree = finch_blist_get_tree();
 	g_object_set(G_OBJECT(tree), "expander-level", 0, NULL);
 	return TRUE;
 }
 
-static gboolean no_group_uninit()
+static gboolean
+no_group_uninit(void)
 {
 	GntTree *tree = finch_blist_get_tree();
 	g_object_set(G_OBJECT(tree), "expander-level", 1, NULL);