bug#21092: 25.0.50; Option `lazy-highlight-max-at-a-time' does not work

[Drew Adams <drew.adams@oracle.com>]

> 1. emacs -Q
> 2. Visit a file - anything other than a tiny one will do.
> 3. Use `customize-option' to set `lazy-highlight-cleanup' to nil
>    and set `lazy-max-at-a-time' to nil.
> 4. Search once for a simple string that occurs multiple times throughout
>    the buffer - e.g., `C-s the RET`.
> 5. Scroll down to see that the matches were not highlighted throughout
>    the buffer.  `lazy-highlight-max-at-a-time' does not work as
>    advertised.

[Typo in step 3: `lazy-max-at-a-time' should be
`lazy-highlight-max-at-a-time' (as in step 5).]

It would be great to hear back about this.  Is this a bug or am I
misunderstanding something?  The doc seems to say that you can expect
that all search hits will be highlighted when the value of
`lazy-highlight-max-at-a-time' is nil: "A value of nil means highlight
all matches."  Even the Customize value menu text says this.