fixup! Followup fix for embedded bytecode loader.

test/tarantool-c-tests/lj-549-lua-load.test.c

@@ -13,6 +13,7 @@
 static const char *
 bc_reader_with_endmark(lua_State *L, void *data, size_t *size)
 {
+	UNUSED(L);
 	UNUSED(data);
 	*size = ~(size_t)0;
 
@@ -41,10 +42,6 @@ enum bc_emission_state {
 	EMIT_EOF,
 };
 
-typedef struct {
-	enum bc_emission_state state;
-} dt;
-
 /*
  * Function returns the bytecode chunk on the first call and NULL
  * and size equal to zero on the second call. Triggers the flag
@@ -54,43 +51,39 @@ static const char *
 bc_reader_with_eof(lua_State *L, void *data, size_t *size)
 {
 	UNUSED(L);
-	dt *test_data = (dt *)data;
-	if (test_data->state == EMIT_EOF) {
+	enum bc_emission_state *state = (enum bc_emission_state *)data;
+	if (*state == EMIT_EOF) {
 		*size = 0;
 		return NULL;
 	}
 
-	static char *bc_chunk = NULL;
-
-	/*
-	 * Minimal size of a buffer with bytecode:
-	 * signature (1 byte) and a bytecode itself (1 byte).
-	 */
-	size_t sz = 2;
-	free(bc_chunk);
-	bc_chunk = malloc(sz);
 	/*
 	 * `lua_load` automatically detects whether the chunk is text
 	 * or binary and loads it accordingly. We need a trace for
 	 * *bytecode* input, so it is necessary to deceive a check in
 	 * `lj_lex_setup`, that makes a sanity check and detects
 	 * whether input is bytecode or text by the first char.
 	 * Put `LUA_SIGNATURE[0]` at the beginning of the allocated
-	 * region.
+	 * nul-terminated region.
 	 */
-	bc_chunk[0] = LUA_SIGNATURE[0];
-	*size = sz;
-	test_data->state = EMIT_EOF;
+	static const char bc_chunk[] = {LUA_SIGNATURE[0], 0};
+	*size = sizeof(bc_chunk);
+	*state = EMIT_EOF;
 
 	return bc_chunk;
 }
 
 static int bc_loader_with_eof(void *test_state)
 {
 	lua_State *L = test_state;
-	dt test_data = {0};
-	test_data.state = EMIT_BC;
-	int res = lua_load(L, bc_reader_with_eof, &test_data, "eof");
+	enum bc_emission_state state = EMIT_BC;
+	int res = lua_load(L, bc_reader_with_eof, &state, "eof");
+
+	/*
+	 * Attempt of loading LuaJIT bytecode via Lua source
+	 * loader function failed: `lj_lex_setup` routine throws
+	 * LUA_ERRSYNTAX error with LJ_ERR_BCBAD payload.
+	 */
 	assert_true(res == LUA_ERRSYNTAX);
 	lua_settop(L, 0);