When placing cocoa on the side of Jungle Wood it still show placing hand animation. If cocoa block has already placed. Here it is result of testing : https://youtu.be/anejN_gh5fs Testing with 1.8
I have attached some picture and video. Note : I think Forge it doesn't matter with test this bug.
Environment
OS : Windows 8.1 Pro CPU : Pentium(R) Dual-Core CPU E5400 @ 2.70GHz RAM : 4 GB DDR2 Java : JDK 1.8.0 Update 66 x64 (Used for modding) Graphic Card : GeForce 9500 GT/PCIe/SSE2
Confirmed for 15w51b.