Segfault when using refined meshes with mortar contact

[dschwen]

Bug Description

Trying to use RefineSidesetGenerator together with penalty mortar contact (refining the contact area). Segfault. And in dbg

No index 18446744073709551615 in ghosted vector.
Vector contains [0,33618)
And empty ghost array.

Tagging @lindsayad

Steps to Reproduce

cd $MOOSE_DIR/modules/contact/test/tests/pdass_problems
../../../contact-opt -i cylinder_friction_penalty.i Mesh/refine/type=RefineSidesetGenerator Mesh/refine/boundaries=3 Mesh/refine/input=input_file Mesh/refine/refinement=1 Mesh/secondary/input=refine

Impact

Prevents users from refining meshes along contact sidesets.

[dschwen]

Oh, interesting, when using the Lagrange Multiplier version on that file I get a different error

../../../contact-opt -i cylinder_friction.i Mesh/refine/type=RefineSidesetGenerator Mesh/refine/boundaries=3 Mesh/refine/input=input_file Mesh/refine/refinement=1 Mesh/secondary/input=refine

yields

*** ERROR ***
'cont_press' of type 'NodalValueSampler' depends on variable(s) 'frictionless_normal_lm'. However, that variable does not appear to be defined on (all of) boundary ''.

[dschwen]

Note that using the BoundaryMarker to perform initial refinement woks fine! This is slightly annoying as that marker existed before the redundant RefineSidesetGenerator was added. @GiudGiud maybe you can figure out what is missing in RefineSidesetGenerator.

[GiudGiud]

maybe just a isnt_prepared called. Would be my guess

[GiudGiud]

I like that you are using RefineSidesetGenerator now :)

[lindsayad]

It's the ordering. Refinement generators must go after the lower-d block generator. I need to add error checking in the lower-d generators to give the user an informative error

[lindsayad]

How about this message?

*** ERROR ***
The following error occurred in the object "secondary", of type "LowerDBlockFromSidesetGenerator".

Only active, level 0 elements can be made interior parents of new level 0 lower-d elements. Make sure that LowerDBlockFromSidesetGenerators are run before any refinement generators

[dschwen]

Yeah. The second sentence is probably the most helpful part for the average user.