Redownloads minecraft.jar file

while using the Dev Launcher, it re-downloads the *.jar file over again every time i go to play. Also there is no offline mode

And no it is not a copy of
https://mojang.atlassian.net/browse/MC-14569

I have solved that issue, but every time I go to play it re-downloads the .jar file so I cant have mods even, without mods it still re-downloads it