From: "Henrique F. Simoes" <henriquesimoes@riseup.net>
Date: Wed, 15 Oct 2025 21:17:51 -0300
Subject: Declare function parameters as required by C23

In C23, having no parameter in a function declaration no longer means an
"unspecified" number of arguments [1]. Therefore, this code fails to
build with this standard. Declare the missing function arguments, so
that it compiles once again with the default standard from modern
compilers, such as GCC 15.

The exception here is the set_{basic,scientific}_object_data functions,
which actually don't use their argument at all. Thus, their unique calls
are changed instead.

Because functions registered by set_disp_ctrl_object_data don't receive
a button pointer as argument as the others, declare a new struct for
holding the entries for that. It is named after "display" as it is only
used for display control buttons.

[1] https://gcc.gnu.org/gcc-15/porting_to.html

Bug-Debian: https://bugs.debian.org/1096669
---
 src/callbacks.c  | 2 +-
 src/galculator.h | 8 +++++++-
 src/ui.c         | 6 +++---
 src/ui.h         | 2 +-
 4 files changed, 12 insertions(+), 6 deletions(-)

diff --git a/src/callbacks.c b/src/callbacks.c
index 503fb13..7259afe 100644
--- a/src/callbacks.c
+++ b/src/callbacks.c
@@ -262,7 +262,7 @@ void
 on_gfunc_button_clicked                (GtkToggleButton       *button,
                                         gpointer         user_data)
 {
-    void    (*func)();
+    void    (*func)(GtkToggleButton *);
     char     *display_string;
 
     if (gtk_toggle_button_get_active(button) == FALSE) return;
diff --git a/src/galculator.h b/src/galculator.h
index 22a4060..bb2ff9f 100644
--- a/src/galculator.h
+++ b/src/galculator.h
@@ -180,9 +180,15 @@ typedef struct {
 typedef struct {
 	char		*button_name;
 	char 		*display_string;
-	void		(*func)();
+	void		(*func)(GtkToggleButton *button);
 } s_gfunc_map;
 
+typedef struct {
+	char		*button_name;
+	char 		*display_string;
+	void		(*func)();
+} s_disp_func_map;
+
 typedef struct {
 	char		*button_name;
 	/* display_string: what to display in history or formula entry. hasn't 
diff --git a/src/ui.c b/src/ui.c
index 6eaac7d..3ed50a5 100644
--- a/src/ui.c
+++ b/src/ui.c
@@ -244,7 +244,7 @@ static void set_disp_ctrl_object_data ()
 {
 	int	counter=0;
 	
-	s_gfunc_map map[] = {\
+	s_disp_func_map map[] = {\
 		{"button_clr", NULL, clear},\
 		{"button_backspace", NULL, backspace},\
 		{"button_allclr", NULL, all_clear},\
@@ -433,14 +433,14 @@ void ui_main_window_buttons_create (int mode)
 		button_box_xml = gtk_builder_file_open (BASIC_GLADE_FILE, TRUE);
         box = GTK_WIDGET(gtk_builder_get_object (view_xml, "classic_view_vbox"));
 		ui_pack_from_xml (box, 2, button_box_xml, "button_box", TRUE, TRUE);
-		set_basic_object_data (button_box_xml);
+		set_basic_object_data ();
 		break;
 	case SCIENTIFIC_MODE:
 		if (button_box_xml) g_object_unref (G_OBJECT(button_box_xml));
 		button_box_xml = gtk_builder_file_open (SCIENTIFIC_GLADE_FILE, TRUE);
         box = GTK_WIDGET(gtk_builder_get_object (view_xml, "classic_view_vbox"));
 		ui_pack_from_xml (box, 2, button_box_xml, "button_box", TRUE, TRUE);
-		set_scientific_object_data (button_box_xml);
+		set_scientific_object_data ();
 		break;
 	case PAPER_MODE:
 		return;
diff --git a/src/ui.h b/src/ui.h
index 90992a2..a20ac3c 100644
--- a/src/ui.h
+++ b/src/ui.h
@@ -74,7 +74,7 @@ void ui_formula_entry_activate ();
 void ui_formula_entry_set (G_CONST_RETURN gchar *text);
 void ui_formula_entry_insert (G_CONST_RETURN gchar *text);
 void ui_formula_entry_backspace ();
-void ui_formula_entry_state ();
+void ui_formula_entry_state (gboolean error);
 void ui_button_set_pan ();
 void ui_button_set_rpn ();
 void ui_relax_fmod_buttons ();