cleanup, release note

Author: wpbonelli

autotest/test_gwt_fmi03.py

@@ -1,12 +1,11 @@
 """
 Tests that multiple GWT models in the same simulation can reference
 the same GWF head and budget files via the FMI package without error.
-Repro https://github.com/MODFLOW-ORG/modflow6/issues/2832.
 
-A transport simulation contains two GWT models, each for a different
-species, both of whose FMI packages point to the same GWF head/budget
-files. Previously this caused an error because the second FMI open
-attempt found the file already open on a unit held by the first FMI.
+Previously this caused an error because the second FMI open attempt
+found the output files already open on units held by the first FMI.
+
+Reported in https://github.com/MODFLOW-ORG/modflow6/issues/2832.
 """
 
 import flopy
@@ -17,16 +16,12 @@
 simname = "gwtfmi03"
 cases = [simname]
 
-# grid
 nlay, nrow, ncol = 1, 1, 10
 delr = delc = 1.0
 top = 1.0
 botm = [0.0]
-# time discretisation
 nper = 2
 tdis_pd = [(5.0, 5, 1.0)] * nper
-
-# transport
 porosity = 0.1
 
 

doc/ReleaseNotes/develop.toml

@@ -73,3 +73,8 @@ description = "Stop with an informative error if a discretization package is mis
 section = "fixes"
 subsection = "model"
 description = "Fix the PRT PRP package's DRAPE option's behavior. A draped particle's release was previously reported in the original release position, followed by a DROPPED (ireason=6) event due to the particle reaching the water table at tracking time as a result of the default DRY\\_TRACKING\\_METHOD setting DROP. This is inconsistent with the intent of the DRAPE option: DRAPE is applied before release to control a particle's release position. Draped particles will now be released in the highest active cell, at the water table if the cell is convertible or at the geometric top if the cell is confined, and no DROPPED event will be reported."
+
+[[items]]
+section = "fixes"
+subsection = "basic"
+description = "Previously, GWF model output files could only be referenced by a single coupled model's FMI package. Referencing the same GWF output files from multiple coupled models would cause a crash. Fix file-opening logic to allow multiple coupled models to refer to the same GWF model's output files."

src/Utilities/BinaryFileReader.f90

@@ -107,7 +107,7 @@ subroutine peek_record(this)
       inquire (this%inunit, pos=this%headernext%pos)
       read (this%inunit, iostat=iostat) this%headernext%kstp, this%headernext%kper
       if (iostat == 0) then
-        call fseek_stream(this%inunit, -2 * I4B, 1, iostat)
+        read (this%inunit, pos=this%headernext%pos, iostat=iostat)
       else if (iostat < 0) then
         this%endoffile = .true.
         if (allocated(this%headernext)) deallocate (this%headernext)

src/Utilities/InputOutput.f90

@@ -101,7 +101,7 @@ subroutine openfile(iu, iout, fname, ftype, fmtarg_opt, accarg_opt, &
         call freeunitnumber(iu)
       end if
       !
-      ! -- Check if file is already open (retained for error reporting only)
+      ! -- Check if file is already open
       inquire (file=fname(1:iflen), number=iuop)
       open (unit=iu, file=fname(1:iflen), form=fmtarg, access=accarg, &
             status=filstat, action=filact, iostat=ivar)