Fix bug with zoom button

xyzzy42 · xyzzy42 · commit 4834501f064d · 2022-10-10T11:56:59.000-07:00
The callback function signature wasn't correct.  This didn't affect
modern platforms like Linux and MacOS, which use register calling
conventions.

But legacy platforms like Windows that use old-style stack based calling
would crash, as a float-point argument was used a pointer.
diff --git a/src/output_panel.c b/src/output_panel.c
@@ -879,8 +879,9 @@ static void handle_zoom_original(GtkScaleButton *b, struct output_panel *op)
 	gtk_widget_queue_draw(op->paperstrip_drawing_area);
 }
 
-static void handle_zoom(GtkScaleButton *b, struct output_panel *op)
+static void handle_zoom(GtkScaleButton *b, gdouble value, struct output_panel *op)
 {
+	UNUSED(value);
 	struct display *ssd = op->snst->d;
 	if (!ssd) return;  // Maybe chart hasn't been displayed even once yet?
 

Original file line number	Diff line number	Diff line change
`@@ -879,8 +879,9 @@ static void handle_zoom_original(GtkScaleButton b, struct output_panel op)`
`879`	`879`	`gtk_widget_queue_draw(op->paperstrip_drawing_area);`
`880`	`880`	`}`
`881`	`881`
`882`		`-static void handle_zoom(GtkScaleButton b, struct output_panel op)`
	`882`	`+static void handle_zoom(GtkScaleButton b, gdouble value, struct output_panel op)`
`883`	`883`	`{`
	`884`	`+ UNUSED(value);`
`884`	`885`	`struct display *ssd = op->snst->d;`
`885`	`886`	`if (!ssd) return; // Maybe chart hasn't been displayed even once yet?`
`886`	`887`