bash - list of breaking change

I know bash tries very hard to keep new versions compatible with previous ones. However they sometime introduced (minor, but still) breaking changes: for exemple when we could no longer have : { foo } # which now hangs but instead had to have : { foo ;} # ie have a ; or a newline before the closing } (not sure which version introduced that, it was more than 20 years ago ^^) My question is : how to find out which other "breaking" changes occured along the whole history of bash updates?