Hello!

"Eli Zaretskii" <eliz@gnu.org> writes:

> Please always mention the bug number, if there is any, in the commit
> log message.
Ok!

> Also, please format the log message according to our conventions, as
> described in CONTRIBUTE.

Read, and new attempt further down.

> This doesn't say enough about what the command does.  How about
>
>   Start an inferior shell in the current project's root directory.

Yeah, that is clearer. I've added it in the attached patch.

Second attempt of a commit message:

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Change default behaviour of 'project-shell'

* lisp/progmodes/project.el (project-shell): If a shell
already is open, pop to that buffer. Otherwise, or if
universal argument is used, open a subsequent shell buffer
and jump to it. Also sets shell buffer name with a prefix of
project root name. (Bug#41858)
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