Cataclysm-dda: Unloading an open container spills the liquid

[BaumgeistOne]

Describe the bug

Using the "unload" command on an open container like a drinking glass next to the player puts the container into the inventory and spills the liquid.

Steps To Reproduce

1. Fill a drinking glass with a liquid, put it on the ground.
2. Try to unload it.
3. Observe the drinking glass being in the inventory and the previously contained liquid spilled on the ground.

Expected behavior

I'd expect to be asked where to fill the liquid, like when unloading an open container held in hands.

Versions and configuration

• OS: Windows
  
  
  
  • OS Version: MINGW/CYGWIN/MSYS2 on Windows 7
  
  
• Game Version: 0.D-13398-g6dc97db [64-bit]
• Graphics Version: Tiles
• Game Language: English [en]
• Mods loaded: [
  Dark Days Ahead [dda],
  Aftershock [aftershock],
  C.R.I.T Expansion Mod [crt_expansion],
  No Rail Stations [No_Rail_Stations],
  Alternative Map Key [alt_map_key],
  Bionic Slots [cbm_slots],
  Fuji's Military Profession Pack [fuji_mpp],
  SpeedyDex [speedydex],
  Stats Through Skills [StatsThroughSkills]
  ]

[wapcaplet]

Confirmed in 0.D-13362 - while wielding an open container in the hands, the "Unload" menu gives a prompt for what to do with the contents:

But if an identical cup of water is sitting on the ground, the "Unload" menu does not prompt after hitting Enter here:

The clean water is dumped on the ground, and the empty cup is picked up.

None of this is mentioned in the event log - the only thing appearing there during these actions is "The opened plastic cup is already empty!":

This issue looks suspiciously similar to #38206 related to unloading a gun - and in fact someone has noted the liquid-unloading issue in the comments there as well.