Safe spawn

In my opinion, if when you spawn/respawn, there should be a few seconds where you are immune to damage, because it is annoying that sometimes when I am joining a server, I am killed by some mob while the screen says "joining". Also this should apply when going through portals, because when I enter a nether portal, I might get killed by pigmen before even the fastest player can do a thing about it. Please, make a time after spawning that I am immune to damage. This can also prevent immediately dying again after respawning, to give the player a chance.