If there's enough of a question that you doubt the safety- then don't bother.
There's literally MILLIONS and MILLIONS of bikes out there. Out of those, there are literally MILLIONS of bikes that are in decent, serviceable shape. Don't waste your time, effort and money on garbage. If there's something you can recover from a destroyed frame- do it- but things reach the end of their usable lives.
__________________
*Recipient of the 2006 Time Magazine "Person Of The Year" Award*
Commence to jigglin’ huh?!?!
"But hey, always love to hear from opinionated amateurs." -says some guy to Mr. Marshall.