bug#9598: 24.0.50; completion goes too far

[Stefan Monnier]

retitle 9598 C-x b completion should also display current buffer.
thanks

> When in the *mail* buffer, I found that C-x b *ma TAB offered me
[...]
> and did not mention *mail* at all.

That's on purpose: C-x b is about moving to another buffer, so it
explicitly excludes the current buffer.

> And the current buffer should not be excluded from a completion list,
> when a completion list is displayed.

It's somewhat difficult to distinguish the "all-completions for display"
case from the "all-completions for completion" in the existing
completion framework.
But I'll see how we can get that behavior.


        Stefan