[petsc-users] KSPSolve with both vectors being the same and MatShell

[Thomas Witkowski]

Following the documentation it is allowed to set the rhs and solution 
vectors in KSPSolve to be the same. When my KSPSolve is based on a 
MatShell, must the MatShell operator function be implemented to handle 
also the case that both vectors are the same? Or can I assume, within 
MatShell, that both vectors, which are provided by KSPSolve, are really 
two different objects?

Thomas