The bug

When I saw the changelog, i got excited a new /function system was added and i quickly tried it on my own.
However, after some time realising what went wrong, /testfor can't detect entities, when a r= tag is present and it's being executed from an other item.

Steps to reproduce

1. Place two repeating command blocks set to Always Active with these commands inside:

/scoreboard players tag @e[type=Item] add gblock {Item:{id:"minecraft:gold_block",Count:1b,Damage:0s}}

/scoreboard players tag @e[type=Item] add gapple {Item:{id:"minecraft:golden_apple",Count:1b,Damage:0s}}

2. Drop a gold block and a golden apple on the same place.
3. Execute this command in chat:

/execute @e[tag=gapple] ~ ~ ~ /testfor @e[tag=gblock,r=1]

After that, try increasing the number of the r=x argument's value.
It won't detect any items when x <= 4.