Issues with integration on interior boundary (dS)

[dokken]

@deshik

Then i have my weak form as,
res_s = res_s + inner(P,grad(v)("+"))*dS(FLAG_INTERFACE) This weak form gave me bad results.
(All the discontinuous parameters required for defining P are restricted appropriately.)

See: Integrating over an interior surface - #4 by MiroK

and for any further questions please make a minimal reproducible example.