Don't close config file when changing preferences

On Linux and MacOS the subsurface_close_conf() doesn't really close the
config file (it flushes writes on MacOS), but on Windows it does
actually close the registry hkey.

Which is bad, if you change the settings multiple times - we assume that
the config file is open the whole time.

So add a "subsurface_flush_conf()" function, and call *that* when
changing configuration parameters.  And call the close function only at
the very end.

Alternatively, maybe we should just open the config file separately
every time. I don't much care, maybe somebody else does.

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

display-gtk.h

@@ -38,6 +38,7 @@ typedef enum {
 extern void subsurface_open_conf(void);
 extern void subsurface_set_conf(char *name, pref_type_t type, const void *value);
 extern const void *subsurface_get_conf(char *name, pref_type_t type);
+extern void subsurface_flush_conf(void);
 extern void subsurface_close_conf(void);
 
 extern const char *subsurface_USB_name(void);

dive.h

@@ -317,6 +317,7 @@ extern void add_event(struct dive *dive, int time, int type, int flags, int valu
 extern void init_ui(int *argcp, char ***argvp);
 
 extern void run_ui(void);
+extern void exit_ui(void);
 
 extern void report_error(GError* error);
 

gtk-gui.c

@@ -423,7 +423,9 @@ static void preferences_dialog(GtkWidget *w, gpointer data)
 		subsurface_set_conf("SAC", PREF_BOOL, BOOL_TO_PTR(visible_cols.sac));
 		subsurface_set_conf("OTU", PREF_BOOL, BOOL_TO_PTR(visible_cols.otu));
 		subsurface_set_conf("divelist_font", PREF_STRING, divelist_font);
-		subsurface_close_conf();
+
+		/* Flush the changes out to the system */
+		subsurface_flush_conf();
 	}
 	gtk_widget_destroy(dialog);
 }
@@ -769,6 +771,11 @@ void run_ui(void)
 	gtk_main();
 }
 
+void exit_ui(void)
+{
+	subsurface_close_conf();
+}
+
 typedef struct {
 	cairo_rectangle_int_t rect;
 	const char *text;

linux.c

@@ -43,6 +43,11 @@ const void *subsurface_get_conf(char *name, pref_type_t type)
 	return NULL;
 }
 
+void subsurface_flush_conf(void)
+{
+	/* this is a no-op */
+}
+
 void subsurface_close_conf(void)
 {
 	/* this is a no-op */

macos.c

@@ -59,13 +59,18 @@ const void *subsurface_get_conf(char *name, pref_type_t type)
 	return NULL;
 }
 
-void subsurface_close_conf(void)
+void subsurface_flush_conf(void)
 {
 	int ok = CFPreferencesAppSynchronize(SUBSURFACE_PREFERENCES);
 	if (!ok)
 		fprintf(stderr,"Could not save preferences\n");
 }
 
+void subsurface_close_conf(void)
+{
+	/* Nothing */
+}
+
 const char *subsurface_USB_name()
 {
 	return "/dev/tty.SLAB_USBtoUART";

main.c

@@ -239,5 +239,6 @@ int main(int argc, char **argv)
 	report_dives(imported);
 
 	run_ui();
+	exit_ui();
 	return 0;
 }

windows.c

@@ -73,10 +73,15 @@ const void *subsurface_get_conf(char *name, pref_type_t type)
 	return NULL;
 }
 
-void subsurface_close_conf(void)
+void subsurface_flush_conf(void)
 {
+	/* I wonder if we should even do this - it's apparently very expensive */
 	if (RegFlushKey(hkey) != ERROR_SUCCESS)
 		printf("RegFlushKey failed \n");
+}
+
+void subsurface_close_conf(void)
+{
 	RegCloseKey(hkey);
 }