til: make til_module_randomize_setup() return -errno

This makes the arg return optional by using a res_arg pointer,
instead returning -ENOMEM when it would have returned NULL on
allocation failures.

This also makes it possible to detect when no setup was
performed, by returning 0 in such a case.  Now returns 1 when
setup occurs and res pointers populated.

3 files changed, 21 insertions, 10 deletions

diff --git a/src/modules/rtv/rtv.c b/src/modules/rtv/rtv.c
index 19dcdca..742b2bc 100644
--- a/src/modules/rtv/rtv.c
+++ b/src/modules/rtv/rtv.c
@@ -155,10 +155,10 @@ static void setup_next_channel(rtv_context_t *ctxt, unsigned ticks)
 		ctxt->channel = &ctxt->channels[i];
 
 		if (!ctxt->channel->settings) {
-			char	*settings;
+			char	*settings = NULL;
 			txt_t	*caption;
 
-			settings = til_module_randomize_setup(ctxt->channel->module, &ctxt->channel->module_setup);
+			(void) til_module_randomize_setup(ctxt->channel->module, &ctxt->channel->module_setup, &settings);
 			caption = txt_newf("Title: %s%s%s\nDescription: %s%s%s",
 						 ctxt->channel->module->name,
 						 ctxt->channel->module->author ? "\nAuthor: " : "",
diff --git a/src/til.c b/src/til.c
index 531c967..f47e8ac 100644
--- a/src/til.c
+++ b/src/til.c
@@ -236,22 +236,24 @@ int til_module_setup(til_settings_t *settings, til_setting_t **res_setting, cons
 }
 
 
-/* originally taken from rtv, this randomizes a module's setup @res_setup, returning args form as well */
-char * til_module_randomize_setup(const til_module_t *module, void **res_setup)
+/* originally taken from rtv, this randomizes a module's setup @res_setup, args @res_arg
+ * returns 0 on no setup, 1 on setup successful with results stored @res_*, -errno on error.
+ */
+int til_module_randomize_setup(const til_module_t *module, void **res_setup, char **res_arg)
 {
 	til_settings_t			*settings;
 	til_setting_t			*setting;
 	const til_setting_desc_t	*desc;
-	char				*arg;
+	int				r = 1;
 
 	assert(module);
 
 	if (!module->setup)
-		return NULL;
+		return 0;
 
 	settings = til_settings_new(NULL);
 	if (!settings)
-		return NULL;
+		return -ENOMEM;
 
 	while (module->setup(settings, &setting, &desc, res_setup) > 0) {
 		if (desc->random) {
@@ -273,8 +275,17 @@ char * til_module_randomize_setup(const til_module_t *module, void **res_setup)
 		}
 	}
 
-	arg = til_settings_as_arg(settings);
+	if (res_arg) {
+		char	*arg;
+
+		arg = til_settings_as_arg(settings);
+		if (!arg)
+			r = -ENOMEM;
+		else
+			*res_arg = arg;
+	}
+
 	til_settings_free(settings);
 
-	return arg;
+	return r;
 }
diff --git a/src/til.h b/src/til.h
index 836907c..572f408 100644
--- a/src/til.h
+++ b/src/til.h
@@ -33,6 +33,6 @@ void til_module_render(const til_module_t *module, void *context, unsigned ticks
 int til_module_create_context(const til_module_t *module, unsigned ticks, void *setup, void **res_context);
 void * til_module_destroy_context(const til_module_t *module, void *context);
 int til_module_setup(til_settings_t *settings, til_setting_t **res_setting, const til_setting_desc_t **res_desc, void **res_setup);
-char * til_module_randomize_setup(const til_module_t *module, void **res_setup);
+int til_module_randomize_setup(const til_module_t *module, void **res_setup, char **res_arg);
 
 #endif