attempted fix for Travis build, which is using older version of gfortran.

Author: jacobwilliams

src/json_value_module.F90

@@ -1222,6 +1222,9 @@ subroutine json_matrix_info_by_path(json,p,path,is_matrix,found,&
 
     type(json_value),pointer :: p_var
     logical(LK) :: ok
+#if defined __GFORTRAN__
+    character(kind=CK,len=:),allocatable :: p_name !! for getting the name
+#endif
 
     call json%get(p,path,p_var,found)
 
@@ -1239,7 +1242,17 @@ subroutine json_matrix_info_by_path(json,p,path,is_matrix,found,&
         if (present(name))     name     = ''
     else
         !get info:
+
+        !get info about the variable:
+#if defined __GFORTRAN__
+        ! [note: passing name directory to this routine seems
+        !        to have a bug on older gfortran versions...
+        call json%matrix_info(p_var,is_matrix,var_type,n_sets,set_size,p_name)
+        if (present(name)) name = p_name
+        if (allocated(p_name)) deallocate(p_name)
+#else
         call json%matrix_info(p_var,is_matrix,var_type,n_sets,set_size,name)
+#endif
         if (json%failed() .and. present(found)) then
             found = .false.
             call json%clear_exceptions()