[Bug c/69415] New: -Wmisleading-indentation warns on "if (__b < __a) return __b; return __a;"

["dmalcolm at gcc dot gnu.org" <gcc-bugzilla at gcc dot gnu dot org>]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=69415

            Bug ID: 69415
           Summary: -Wmisleading-indentation warns on "if (__b < __a)
                    return __b; return __a;"
           Product: gcc
           Version: 6.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c
          Assignee: unassigned at gcc dot gnu.org
          Reporter: dmalcolm at gcc dot gnu.org
  Target Milestone: ---

This Debian bug report for "resiprocate":
  https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=812005
has:
> In file included from ../rutil/Data.hxx:13:0,
>                  from ../rutil/Log.hxx:4,
>                  from ../rutil/SysLogBuf.hxx:12,
>                  from SysLogStream.cxx:1:
> ../rutil/compat.hxx: In function 'const _Tp& resip::resipMin(const _Tp&, const _Tp&)':
> ../rutil/compat.hxx:187:31: warning: statement is indented as if it were guarded by... [-Wmisleading-indentation]
>     if (__b < __a) return __b; return __a;
>                                ^~~~~~
>
> ../rutil/compat.hxx:187:4: note: ...this 'if' clause, but it is not
>     if (__b < __a) return __b; return __a;
>     ^~

The code in question is:

  if (__b < __a) return __b; return __a;

(I wasn't able to locate it within https://github.com/resiprocate/resiprocate )

Arguably this conditional could use an "else", but this construct appears to be
present in an old version of our STL implemenation, at least e.g.:
  https://gcc.gnu.org/ml/libstdc++/2003-02/txt00002.txt

How common is this construct?

Should we warn about it?