This makes perfect sense as an explanation for the lack of breeding I'm seeing recently.
The same occurs when opening chat via the / key, which is annoying because when pressing /, Minecraft automatically inserts / at the beginning, so it inserts two / characters.
I use the gnome window manager
Also cannot open trapdoors at build limit. Appears to open (client-side), but closes immediately, with build height message
I believe I am still experiencing this issue in 14w30c
I think part of the same issue: placing a new, undamaged tool, in the same hotbar slot as a recently-broken tool, can sometimes cause the new tool to disappear
the same problem occurs when attempting to store into storage when explicitly setting a type of "long"
eg:
/execute store result storage t:seed aLong long 1 run seed
=> Seed: [5486814582284274048]
/data get storage t:seed aLong
=> Storage t:seed has the following contents: -847459968L