Why is there extra space when joining and one line ends with dot?

[Igor]

Vim 8.2.0003 on Linux.

Having a text:

aaa

bbb

and cursor in first line and join the lines with J normal mode ommand and the result is:

aaa bbb

as expected.

But if there is full-stop character at the end of first line:

aaa.

bbb

and cursor also in first line and executing J

aaa.  bbb

and there double space.

Why is there a double space? Is this a bug?

The same problem appears with "!" and "?" characters instead of "."

[Tony Mechelynck]

No, it is not a bug, it is a feature: some manuals of style require
two spaces after a full stop or an exclamation or question mark.

See :help 'joinspaces'

Best regards,
Tony.

[Igor]

Tony,

little bit weird, to be set as default.

Actually to me it is important I can fix it with:

set nojoinspaces

in my .vimrc

Thanks a lot

[Gary Johnson]

On 2019-12-14, Igor wrote:
> Tony,
> little bit weird, to be set as default.

No, not really. All of us, at least in the U.S., who learned to
type in school around the time that vi was invented were taught to
put two spaces between sentences. Hitting the space bar twice
following end-of-sentence punctuation is automatic for us. Of
course vi would support that rule.

Regards,
Gary