fix: modern diag manager allocation failures when using two empty fil…

…es (#1503)

diag_manager/fms_diag_yaml.F90

@@ -418,6 +418,7 @@ subroutine diag_yaml_object_init(diag_subset_output)
         else
           call diag_get_value_from_key(diag_yaml_id, diag_file_ids(i), "file_name", filename)
           call mpp_error(NOTE, "diag_manager_mod:: the file:"//trim(filename)//" has no variables defined. Ignoring!")
+          if (allocated(filename)) deallocate(filename)
           ignore(i) = .True.
         endif
     endif
@@ -1748,7 +1749,7 @@ subroutine fms_diag_yaml_out()
           tmpstr1 = ''; tmpstr1 = string(varptr%n_diurnal)
           call fms_f2c_string(vals3(key3_i)%val9, tmpstr1)
         endif
-        
+
         if( varptr%pow_value .gt. 0) then
           tmpstr1 = ''; tmpstr1 = string(varptr%pow_value)
           call fms_f2c_string(vals3(key3_i)%val10, tmpstr1)

test_fms/diag_manager/test_time_none.sh

@@ -185,6 +185,24 @@ test_expect_success "Testing diag manager that defined a diag file with no varia
   mpirun -n 6 ../test_reduction_methods
 '
 
+cat <<_EOF > diag_table.yaml
+title: test_none
+base_date: 2 1 1 0 0 0
+diag_files:
+- file_name: test_empty_file
+  time_units: hours
+  unlimdim: time
+  freq: 6 hours
+- file_name: test_empty_file2
+  time_units: hours
+  unlimdim: time
+  freq: 6 hours
+_EOF
+
+my_test_count=`expr $my_test_count + 1`
+test_expect_success "Testing diag manager that defined 2 diag file with no variables (test $my_test_count)" '
+  mpirun -n 6 ../test_reduction_methods
+'
 cat <<_EOF > diag_table.yaml
 title: test_none
 base_date: 2 1 1 0 0 0