Originally Posted by GearNut
It looks like the dropout stamping was bent when the weld was broken.
If that is true, straighten it out before having it welded.
I highly recommend that you TIG weld it, unless you know someone who is very skilled with MIG welding. TIG is better though, it can reduce the chance of heat embrittlement considering that you will be welding right on top of an old weld.
A reinforcing strap along the inside would help too.
Whatever you choose, if it breaks again it very well could cause a crash. Choose wisely.
You may be better served by rebuilding the whole dropout section on both sides of the bike so you know where you stand on its strength.