(THIS HAS BEEN RESOLVED)
Searge: "Decimals are not recognized, the selector parameters are all integers. But it should now consistently fail instead of creating a player on the scoreboard with the selector as name."

Using decimals in the arguments for a player causes the command to fail. It appears that the player arguments are registered as the name of a player or it gives an error stating that "The entity UUID provided is in a invalid format". This is present in both Singleplayer and Multiplayer.

Doing /tp @a[ry=95.0,rym=85.0] ~0 ~10 ~0 should teleport any player looking in that direction. It instead says "The entity UUID provided is in an invalid format" without moving the player. If the command were to be /tp @a[ry=95,rym=85] ~0 ~10 ~0 , no error appears and the player is teleported if looking in the specified direction. (Notice the only difference is adding decimals to specify the exact direction)

Steps to reproduce:

1.

/tp @p ~0 ~0 ~0 90 0

2.

/testfor @p[ry=95,rym=85]

(Should say "Found [Your username here]")

3.

/testfor @p[ry=95.0,rym=85.0]

(Should say "The entity UUID provided is in an invalid format")

This also applies to giving coordinates with decimals. If you would like to reproduce the issue using coordinates instead of rotational values, here are the commands:

1.

/tp @p 0 1 0

2.

/testfor @p[0,1,0,r=1]

3.

/testfor @p[0.0,1.0,0.0,r=1]

In the examples I'm using easy numbers for the sake of simplicity, but a real-minecraftian-world command that needs this kind of usage looks more like this:

/scoreboard players set @a[-34,21,128,r=10,rym=-122.2,ry=-119.1] hBlock 1

The attached image shows the result of using this command.

When using scoreboards, a player is created with the name "@a[-34,21,128,r=10,rym=-122.2,ry=-119.1]" instead of giving a score of 1 to players who are facing in that direction. If you wish to reproduce this, here are the commands:

1.

/scoreboard objectives add test dummy Test

2.

/scoreboard objectives setdisplay sidebar test

3.

/scoreboard players set @p[r=5] test 1

(Should display your username on the sidebar with a 'test' score of 1.
4.

/scoreboard players set @p[r=5.0] test 1

(Instead of finding the player, it creates a player with the name "@p[r=5.0]")

As the last author of this bug brings up a good point, I'm going to keep their original post here:

As the title states, when using a command such as /testfor, you cannot enter the command with decimals in the arguments.

Example:

testfor @p[10.0,64,0.0,5]

The problem is how the game interprets the command when no decimals are used.

testfor @p[10,64,0,5]

In this example, the game actually looks at x=10.5 and z=0.5, and you cannot center your check point from there.

With how it is now, all points need to be a circle with an odd width, instead of even.