/say and /w command bug

when typing "/say @a[r=100], hello world" placing the comma after the ] causes it to say "@a[r=100]," and not the players name, but when i put a space between them "@a[r=100] ," it says the right names but puts a space between the comma in the chat"evldmon , hello world", this looks grammatically incorrect. I don't know if this is a bug but it should be looked at