Force update of the focused widget on the Edit tab if it’s a GtkSpinButton

This is required because when the user changes tabs with an accel after
manually changing a spin button’s value, but without pressing Enter
("activate") or leaving the spin button, the spin button will reflect the
old value instead.

src/ag-window.c

@@ -565,6 +565,7 @@ ag_window_recalculate_chart(AgWindow *window, gboolean set_everything)
     GtkTextIter     start_iter,
                     end_iter;
     GsweTimestamp   *timestamp;
+    GtkWidget       *current;
     gint            db_id = (priv->saved_data) ? priv->saved_data->db_id : -1;
 
     south = gtk_toggle_button_get_active(
@@ -575,6 +576,15 @@ ag_window_recalculate_chart(AgWindow *window, gboolean set_everything)
             GTK_TOGGLE_BUTTON(priv->west_long)
         );
 
+    // If the current widget is a spin button, force it to update. This is
+    // required when the user enters a new value in a spin button, but doesn't
+    // leave the spin entry before switching to the chart tab with an accel.
+    current = gtk_window_get_focus(GTK_WINDOW(window));
+
+    if (GTK_IS_SPIN_BUTTON(current)) {
+        gtk_spin_button_update(GTK_SPIN_BUTTON(current));
+    }
+
     edit_data = g_new0(AgDbSave, 1);
 
     edit_data->db_id = db_id;