Fix potential memory leaks and other small improvements

1 files changed, 29 insertions, 11 deletions

diff --git a/c_src/sdl_window.c b/c_src/sdl_window.c
index c35fb0c..c644c09 100644
--- a/c_src/sdl_window.c
+++ b/c_src/sdl_window.c
@@ -75,12 +75,11 @@ NIF_CALL_HANDLER(thread_create_window)
 
 NIF_FUNCTION(create_window)
 {
-	char* title = (char*)enif_alloc(255);
+	unsigned int len;
+	char* title;
 	int x, y, w, h;
 	Uint32 flags = 0;
 
-	BADARG_IF(!enif_get_string(env, argv[0], title, 255, ERL_NIF_LATIN1));
-
 	if (enif_is_atom(env, argv[1])) {
 		BADARG_IF(!atom_to_window_pos(env, argv[1], &x));
 	} else {
@@ -97,6 +96,16 @@ NIF_FUNCTION(create_window)
 	BADARG_IF(!enif_get_int(env, argv[4], &h));
 	BADARG_IF(!list_to_window_flags(env, argv[5], &flags));
 
+	// Getting the title last to simplify the code due to memory allocation.
+
+	BADARG_IF(!enif_get_list_length(env, argv[0], &len));
+	title = (char*)enif_alloc(len + 1);
+
+	if (!enif_get_string(env, argv[0], title, len + 1, ERL_NIF_LATIN1)) {
+		enif_free(title);
+		return enif_make_badarg(env);
+	}
+
 	return nif_thread_call(env, thread_create_window, 6,
 		title, x, y, w, h, flags);
 }
@@ -465,17 +474,18 @@ NIF_CALL_HANDLER(thread_set_window_brightness)
 NIF_FUNCTION(set_window_brightness)
 {
 	void* window_res;
-	double f;
-	double *fp;
+	double *brightnessPtr;
 
 	BADARG_IF(!enif_get_resource(env, argv[0], res_Window, &window_res));
-	BADARG_IF(!enif_get_double(env, argv[1], &f));
 
-	fp = (double*)enif_alloc(sizeof(double));
-	*fp = f;
+	brightnessPtr = (double*)enif_alloc(sizeof(double));
+	if (!enif_get_double(env, argv[1], brightnessPtr)) {
+		enif_free(brightnessPtr);
+		return enif_make_badarg(env);
+	}
 
 	return nif_thread_call(env, thread_set_window_brightness, 2,
-		NIF_RES_GET(Window, window_res), fp);
+		NIF_RES_GET(Window, window_res), brightnessPtr);
 }
 
 // set_window_fullscreen
@@ -636,10 +646,18 @@ NIF_CAST_HANDLER(thread_set_window_title)
 NIF_FUNCTION(set_window_title)
 {
 	void* window_res;
-	char* title = (char*)enif_alloc(255);
+	unsigned int len;
+	char* title;
 
 	BADARG_IF(!enif_get_resource(env, argv[0], res_Window, &window_res));
-	BADARG_IF(!enif_get_string(env, argv[1], title, 255, ERL_NIF_LATIN1));
+
+	BADARG_IF(!enif_get_list_length(env, argv[1], &len));
+	title = (char*)enif_alloc(len + 1);
+
+	if (!enif_get_string(env, argv[1], title, len + 1, ERL_NIF_LATIN1)) {
+		enif_free(title);
+		return enif_make_badarg(env);
+	}
 
 	return nif_thread_cast(env, thread_set_window_title, 2,
 		NIF_RES_GET(Window, window_res), title);