[Libmesh-devel] Behavior change in EquationSystems::read()

[Roy S. <roy...@ic...>]

My EquationSystems objects often include System subclasses (e.g.
NavierSystem in ex18) which don't exist in the library itself.
Currently, restarting such a System from a .xda file requires a
workaround: my applications call add_system() for any peculiar System
objects before ever calling EquationSystems::read(); read() then fills
those System objects in-place with the data from disk.

One of the changes I've needed to make this work will change the
behavior of EquationSystems::read(), however, and I plan to commit
that change to CVS shortly: the code "if (read_header) this->clear();"
in equation_systems_io.C will be commented out.  You can't fill a
System object with data if you've just deleted it.

If anyone's code depends on EquationSystems::read() clearing existing
data, please change your application to call clear() manually before
the read() call.
---
Roy