[Memory issues] A tale of memory leaks (act 1, scene 1)

[mjuhoor]

• MUSIC has a problem with memory consumption. This issue is aimed at a particular
  critical bug that causes lots of memory leaks:

vtkPolyData* mesh = ...
vtkMetaSurfaceMesh* metaMesh = ...
medAbstractData* data = ...

metaMesh->SetDataSet(mesh);
data->setData(metaMesh);

Looking at the source code of medInria, one can observe that:

• 'SetDataSet(...)' does a deep copy of the parameter
• 'setData(...)' hides a smart pointer assignment, and thus increases the count reference.
  Therefore, both 'mesh' and 'metaMesh' should be deleted.

In numerous cases, this rule is not respected, causing multiple memory leaks.

[fcollot]

(I discussed this "live" with @mjuhoor yesterday but for the record I'll post it here)
This can be fixed by refactoring this sort of function to take smart pointers, so that the caller does not need to worry about who owns the pointer, and can delete it on their side without a problem.

[fcollot]

I'll do this as part of the architecture refactoring.