util-src: Use the luaL_pushfail API added in Lua 5.4 to highlight all failure conditions Actually just an alias of pushnil, but it does make it more obvious where the failure conditions are, which is good for readability.

author: Kim Alvefur <zash@zash.se>
date: Sun, 07 Jun 2020 02:25:56 +0200
parent: 10901:5e33926f4b43
child: 10953:c3b3ac63f4c3
--- a/util-src/ringbuffer.c	Sun Jun 07 02:14:55 2020 +0200
+++ b/util-src/ringbuffer.c	Sun Jun 07 02:25:56 2020 +0200
@@ -6,6 +6,10 @@
 #include <lua.h>
 #include <lauxlib.h>
 
+#if (LUA_VERSION_NUM < 504)
+#define luaL_pushfail lua_pushnil
+#endif
+
 typedef struct {
 	size_t rpos; /* read position */
 	size_t wpos; /* write position */
@@ -152,7 +156,7 @@
 	int peek = lua_toboolean(L, 3);
 
 	if(r > b->blen) {
-		lua_pushnil(L);
+		luaL_pushfail(L);
 		return 1;
 	}
 
@@ -204,7 +208,7 @@
 
 	/* Does `l` bytes fit? */
 	if((l + b->blen) > b->alen) {
-		lua_pushnil(L);
+		luaL_pushfail(L);
 		return 1;
 	}