Unable to put an item back to its original spot when forceFallback: true

[kevinzang]

http://jsbin.com/jozakuqesi/1/edit?html,css,js,output

In one motion, drag item "bar 1" to the other list, and then try to drag it back to its original spot. It is not possible in one motion, but it works if you drop first in the other list, then drag it again to the original spot.

In this case, I noticed _ghostIsLast returns false when withFallback: true, but returns true when withFallback: false, but I am not sure if this is the root cause of this bug. Another suspect is the if (el.children.length === 0) check. That looks like it is trying to check "if the sortable list is empty", but in this case the list is not actually empty because it contains invisible clone element as well as fixed position fallback element.

[tplk]

Same here, what can be done to fix this?

[owen-m1]

Solved in 1.8.0, using emptyInsertThreshold option