Version 4.0.4.400
-Grape vines no longer break when no longer over farmland vs. dirt.
Still bugged, jumped on the farmland under a vine and turned it to dirt, vine broke. (Oddly enough, mature thistles did not break when I did the same thing.)

@Alatyami Did we introduce a change about the breaking behavior of grape vines? As far as I know they suppose to break when the farmland is destroyed. That is how it was originally programmed.

Non breaking thistles is clearly a bug.

@Avatair Yes, It's in the bugfix section of the changelog for the 4.0.4.400 release candidate.
It's there to combat #61 .

Since grape vines do not need continual replanting the argument was made that Grape Vines should not break when the ground is no longer farmland. In the commit the only change was adding .DIRT although that does mean that if it turns into grass canSustainBush will return false.

Confirming that this is still a bug in build growthcraft-1.12.2-4.0.4.400.DEV.52b3e0d.