[MC-38051] "Couldn't process command" error in server log when no players connected

If a command block on a clock running a command similar to

/tp @r[x,y,z,r] x y z

exists in a world on a multiplayer server, when there are no players connected to the server, the server console is spammed with this error:

[timestamp] [Server thread/ERROR]: Couldn't process command
java.lang.NullPointerException
        at java.util.Collections.shuffle(Collections.java:497) ~[?:1.7.0_45]
        at java.util.Collections.shuffle(Collections.java:469) ~[?:1.7.0_45]
        at ad.c(SourceFile:127) ~[minecraft_server.1.7.2.jar:?]
        at ad.a(SourceFile:44) ~[minecraft_server.1.7.2.jar:?]
        at y.d(SourceFile:114) ~[minecraft_server.1.7.2.jar:?]
        at bu.b(SourceFile:33) ~[minecraft_server.1.7.2.jar:?]
        at z.a(SourceFile:58) [minecraft_server.1.7.2.jar:?]
        at afb.a(SourceFile:79) [minecraft_server.1.7.2.jar:?]
        at ain.a(SourceFile:49) [minecraft_server.1.7.2.jar:?]
        at mj.a(SourceFile:405) [minecraft_server.1.7.2.jar:?]
        at mj.b(SourceFile:134) [minecraft_server.1.7.2.jar:?]
        at net.minecraft.server.MinecraftServer.u(SourceFile:503) [minecraft_server.1.7.2.jar:?]
        at lj.u(SourceFile:265) [minecraft_server.1.7.2.jar:?]
        at net.minecraft.server.MinecraftServer.t(SourceFile:441) [minecraft_server.1.7.2.jar:?]
        at net.minecraft.server.MinecraftServer.run(SourceFile:358) [minecraft_server.1.7.2.jar:?]
        at ky.run(SourceFile:617) [minecraft_server.1.7.2.jar:?]

As soon as a player connects this stops.

edit: simplification