Sorry, forgot to attach the patch to the revised testcase f2018_obs.f90.
Here it is.

Regards,
Harald

Adjusted ChangeLog:

2019-02-13  Harald Anlauf  <anlauf@gmx.de>

	PR fortran/88248
	* gfortran.dg/pr88248.f90: New test.
	* gfortran.dg/f2018_obs.f90: Updated test.

On 02/13/19 23:38, Harald Anlauf wrote:
> The attached patch moves the check for labeled DO statements to
> the place where a label is referenced instead of where a label
> was defined, which lead to false positives.
> 
> Regtested on x86_64-pc-linux-gnu.
> 
> OK for trunk?
> 
> Thanks,
> Harald
> 
> 2019-02-13  Harald Anlauf  <anlauf@gmx.de>
> 
> 	PR fortran/88248
> 	* symbol.c: Move check for labeled DO statement from
> 	gfc_define_st_label to gfc_reference_st_label.
> 
> 2019-02-13  Harald Anlauf  <anlauf@gmx.de>
> 
> 	PR fortran/88248
> 	* gfortran.dg/pr88248.f90: New test.
>