🚀 go-pugleaf

I have a question about a passage in the O'Reilley Xlib reference
manual (1988) for XAllocColor:

"If no matching cell exists but there are unallocated cells, a cell
is allocated to match the specified RGB values. If no matching cell 
exists and there are no unallocated cells, the closest available 
colorcell that has already been allocated (by this or any other client) 
is returned."

I believe that this statement of the behavior of XAllocColor is
incorrect, for the following reason:

1) It does not explicitly state that this applies only to dynamic
   visuals.  (But it's pretty obvious, so this is not that bad).

2) No mention is made of this in the R4 protocol document.  In fact,
   the protocol does not explicitly define what the behavior should 
   be in this situation.

3) The R4 Xlib documentation also does not explicitly define this 
   behavior.

4) The R4 sample server code doesn't not implement this behavior.  
   Instead, a BadAlloc is returned in this situation.

All of these lead me to believe that the behavior documented
in O'Reilley is incorrect, but I wanted to confirm this with
others because the described behavior is somewhat intuitive.

Theory: this is a remnant from earlier versions of the protocol?