[Bug] Export path is subject to peg revision parsing

Folks,

I could have either found a bug in the handling of input or a document 
insufficiency. We have received a downstream bug: 
https://github.com/websvnphp/websvn/issues/189

It boils down to this command:
> # svn  export -r 50 'file:///var/svn/Playground/me%40you.d/@'  [email protected]
> svn: E200009: '[email protected]': a peg revision is not allowed here

I fail to see here that PATH1 is subject to PEGREV parsing:
> # svn help export
> export: Create an unversioned copy of a tree.
> usage: 1. export [-r REV] URL[@PEGREV] [PATH]
>        2. export [-r REV] PATH1[@PEGREV] [PATH2]
> 
>   1. Exports a clean directory tree from the repository specified by
>      URL, at revision REV if it is given, otherwise at HEAD, into
>      PATH. If PATH is omitted, the last component of the URL is used
>      for the local directory name.

Verified with:
> # svn --version
> svn, version 1.10.8 (r1899510)
>    compiled Jan 31 2023, 15:01:25 on amd64-portbld-freebsd12.4
and
> # svn --version
> svn, Version 1.14.2 (r1899510)
>    übersetzt am Jun 16 2023, um 09:25:07 auf amd64-portbld-freebsd12.4

This works:
> # svn  export -r 50 'file:///var/svn/Playground/me%40you.d/@'  [email protected]@
> A    [email protected]
> Exported revision 50.

Now the opposite:
> # svn  export -r 50 'file:///var/svn/Playground/me%40you.d/@'  [email protected]@99
> svn: E200009: '[email protected]@99': a peg revision is not allowed here

this seems to be a safe bet to always append an @ to the PATH1:
> # svn  export -r 50 'file:///var/svn/Playground/hallo.c@'  hallo.c@
> A    hallo.c
> Export complete.
> # ll hallo.c
> -rw-r--r--  1 root  wheel  104 2017-03-27 13:56 hallo.c

Any clarification is appreciated. JIRA doesn't contain anything useful.

Michael