As indicated by the bold text, it is passing constraintInsets.length, when it should be constraintInsets.left.
Also, in the Ext.util.Region.adjust() function, it is adding the right and bottom insets to the constrainTo values. But, since these are defined as insets, it should be subtracting the insets from the right and bottom values.
Not a simple test case. But, if they just look at the code in Ext.util.Positionable.getConstrainVector(), where constrainTo.adjust() is called, it is very obvious that the last parameter should be constraintInsets.left, not constrainInsets.length.
For the second part, I'm not as concerned about it, I can just make my insets a negative number to achieve what I want.