Client version: 1.8.9, 1.9.4, 1.12.2 / 1.13.2
Server OS: Linux
Cuberite Commit id: latest master

Expected behavior

Right clicking an empty map creates a new map and allocates a new map number.

Actual behavior

The new map is created with the expected next map number but the count of "Map #0" items also increases by one.

Steps to reproduce the behavior

Give yourself some empty maps (works in creative or survival). Right click. Now you have a "Map #0". Right click again and you have "Map #1" and two "Map #0"s. This continues until you have a whole stack of "Map #0"s then the duping stops - it doesn't creates a new stack.

In 1.13.2 the behaviour is... different... Sometimes it adds a map to a new inventory slot, sometimes it increases the count on an existing slot (the last one added?). However ALL maps appear as "Map #0". And yes, I know SendMap isn't implemented for the 1.13 protocol and I'm not expecting the maps to have any actual content. But surely the items should be somewhat sensible? I'd be fine if it just didn't work but this is just weird!