Milking a cow or mooshroom with a single bucket or bowl (not a stack of them) causes the player to immediately consume the milk (or mushroom stew, if the player's hunger bar is not full). This bug only appears when using touch input, not when using a mouse. Controller input not yet tested.
When doing this, the selected hotbar item changes from an empty bucket/bowl to a full one. Doing this by touch input seems to be the root of the problem. If the player uses a stack of buckets/bowls, then the full bucket/bowl does not become the selected hotbar item and the bug does not occur.
In trying to milk a cow with iron pot should preserve the milk in the pot, the error is that milk is drunk without notice.
Tablet alcatel one touch pixi 8 minecraft pocket edition 0.13.0 alpha build