The Bug:
Right-clicking water with glass bottles in creative mode whilst having a potion in your inventory doesn't give water bottles.
Steps to Reproduce:
Switch into creative mode and get a glass bottle and a drinkable potion.
Attempt to obtain a water bottle by right-clicking on some water while holding a glass bottle.
Take note as to whether or not right-clicking water with glass bottles in creative mode whilst having a potion in inventory gives water bottles.
Observed Behavior:
Nothing happens and you aren't given a water bottle.
Expected Behavior:
You would be given a water bottle.
Can confirm this behavior, it is indeed playing the sound when you try to grab water but no water bottles are added to your inventory, I can upload the video in a bit
Edit: From further testing, this happens without the potion in the offhand as well