Physical group on multiple volumes leads to "" physical names for some volumes [C++ API]
When there is a physical group that is made up by more than one volume, some of the volumes will not return a correct physical name after calls to gmsh::model::getPhysicalName(dim, tag, physName);
Here is an example mesh file and cpp file showing the behaviour.
pGroupBug.msh pGroupBugTest.cpp
I have tried with mesh formats 2.2, 3 & 4.