Hi everyone thanks for coming in this report (this bug is only for 1.9 not 1.8) Hope this gets fixed since it looks strange
By the way here are the details explaining the bug:
What i should expect is:
The sword in my main and offhand slot should block me both
What i expected is:
Only the sword in the right hand blocked me
How to reproduce the bug:
1. Get a sword and put it in your main hand and offhand slot
2. Now right click (you will notice the sword in your main hand blocked you, with the left one still inplace)
3. Now go and press your camera perspective key 3 times (See?)
As you can see in the picture you can now block with your sword in your left hand, but you are when you are holding a sword in the right hand the right one will block you instead, however if you look at yourself with the camera perspective number 3 you will see both of the swords you are holding blocks you
Am not sure if this a bug or "natural happening" but it really looks strange
:/