This ticket is basically identical to MCPE-11583, but for mooshrooms, mushroom stew and bowls instead of cows, milk and buckets.
To reproduce
Ensure your hunger bar is not full
Place a single bowl in your hotbar and select it
Click "Milk Stew" button when next to a mooshroom
Observe your player immediately consume the mushroom stew"
I expected the mushroom stew to replace the empty bowl in your hotbar and the player not to immediately consume the stew.
If you try again with a stack of bowls, the player does not immediately consume the stew, likely because the selected item does not change from an empty bowl to a bowl of mushroom stew. I have no clue why there's a difference when using a single bowl with touch or mouse input.
Tested in single player survival on Samsung Galaxy S6 (SM-G920W8), Android 5.1.1 and Asus B121 Tablet Win10 Pro x64 10.0.10586 build 10586 (using touch input, I cannot reproducing using mouse input)
Linked issues
Comments 3

updated MCPE-11583 to cover all cases.

updated MCPE-11583 to cover all cases.
updated MCPE-11583 to cover all cases.