Lua: re-implement and test box.insert().

Implement INSERT command in Box. Minor cleanups in Lua.

core/tarantool_lua.m

@@ -276,6 +276,7 @@ tarantool_lua_init()
 		return L;
 	luaL_openlibs(L);
 	luaL_register(L, "box", boxlib);
+	lua_pop(L, 1);
 	lua_register(L, "print", lbox_print);
 	tarantool_lua_load_cfg(L, &cfg);
 	L = mod_lua_init(L);

mod/box/box.lua

@@ -36,7 +36,16 @@ function box.replace(namespace, ...)
                                  unpack(tuple))))
 end
 
-box.insert = box.replace
+-- insert a tuple (produces an error if a tuple already exists
+function box.insert(namespace, ...)
+    tuple = {...}
+    return select(2,
+        box.process(13, box.pack('iii'..string.rep('p', #tuple),
+                                 namespace,
+                                 3, -- flags, BOX_RETURN_TUPLE | BOX_ADD
+                                 #tuple, -- cardinality
+                                 unpack(tuple))))
+end
 
 function box.update(namespace, key, format, ...)
     ops = {...}

mod/box/box_lua.m

@@ -372,8 +372,10 @@ mod_lua_init(struct lua_State *L)
 	lua_pushstring(L, tuplelib_name);
 	lua_setfield(L, -2, "__metatable");
 	luaL_register(L, NULL, lbox_tuple_meta);
+	lua_pop(L, 2);
 	/* Load box.lua */
 	(void) luaL_dostring(L, &_binary_box_lua_start);
+	assert(lua_gettop(L) == 0);
 	return L;
 }
 

test/box/lua.test

@@ -72,6 +72,8 @@ exec sql "call box.select(0, 0, 'abcd')"
 exec sql "call box.delete(0, 'abcd')"
 exec sql "call box.delete(0, 'defc')"
 exec sql "call box.insert(0, 'test', 'old', 'abcd')"
+# test that insert produces a duplicate key error
+exec sql "call box.insert(0, 'test', 'old', 'abcd')"
 exec sql "call box.update(0, 'test', '=p=p', 0, 'pass', 1, 'new')"
 exec sql "call box.select(0, 0, 'pass')"
 exec sql "call box.update(0, 'miss', '+p', 2, '\1\0\0\0')"