luzer: fix argv building

Author: ligurio

CHANGELOG.md

@@ -26,3 +26,4 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 - Fix searching Clang RT.
 - Stack overflow due to recursive traceback calls.
+- Fix a crash due to incorrect `argv` building.

luzer/luzer.c

@@ -329,36 +329,34 @@ luaL_fuzz(lua_State *L)
 	char **argv = malloc(1 * sizeof(char*));
 	if (!argv)
 		luaL_error(L, "not enough memory");
+	argv[0] = "<test name>";
+	argc++;
 	const char *corpus_path = NULL;
 	while (lua_next(L, -2) != 0) {
+		const char *key = lua_tostring(L, -2);
+		const char *value = lua_tostring(L, -1);
+		if (strcmp(key, "corpus") == 0) {
+			corpus_path = strdup(value);
+			lua_pop(L, 1);
+			continue;
+		}
 		char **argvp = realloc(argv, sizeof(char*) * (argc + 1));
 		if (argvp == NULL) {
 			free(argv);
 			luaL_error(L, "not enough memory");
 		}
-		const char *key = lua_tostring(L, -2);
-		const char *value = lua_tostring(L, -1);
-		if (strcmp(key, "corpus") != 0) {
-			size_t arg_len = strlen(key) + strlen(value) + 3;
-			char *arg = calloc(arg_len, sizeof(char));
-			if (!arg)
-				luaL_error(L, "not enough memory");
-			snprintf(arg, arg_len, "-%s=%s", key, value);
-			argvp[argc] = arg;
-			argc++;
-		} else {
-			corpus_path = strdup(value);
-		}
-		lua_pop(L, 1);
+		size_t arg_len = strlen(key) + strlen(value) + 3;
+		char *arg = calloc(arg_len, sizeof(char));
+		if (!arg)
+			luaL_error(L, "not enough memory");
+		snprintf(arg, arg_len, "-%s=%s", key, value);
+		argvp[argc] = arg;
+		argc++;
 		argv = argvp;
+		lua_pop(L, 1);
 	}
 	if (corpus_path) {
-		argv[argc] = (char*)corpus_path;
-		argc++;
-	}
-	if (argc == 0) {
-		argv[argc] = "";
-		argc++;
+		argv[argc-1] = (char*)corpus_path;
 	}
 	argv[argc] = NULL;
 	lua_pop(L, 1);