[Bug c++/126924] New: Wimplicit-fallthrough not issued if next case only contains a break

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=126924

            Bug ID: 126924
           Summary: Wimplicit-fallthrough not issued if next case only
                    contains a break
           Product: gcc
           Version: 16.2.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c++
          Assignee: unassigned at gcc dot gnu.org
          Reporter: headch at gmail dot com
  Target Milestone: ---

This code does not generate a Wimplicit-fallthrough warning:

void g();

void f(int x) {
    switch(x) {
        case 1:
          g();
        case 2:
          //g();
          break;
    }
}

It does if you uncomment the commented-out line. It seems to me that it should
generate a Wimplicit-fallthrough warning either way—my understanding is that
the intention is to not generate the warning if the case you are falling *from*
is empty (so you can group case labels together that all have the same
handling), not if the case you are falling *into* is empty (which seems like
nothing special, and ought to be warned about).