CarpetLib: Correct regridding communication schedule

Handle correctly the case where the multi-patch processor decomposition
changes during regridding.

1 files changed, 5 insertions, 0 deletions

diff --git a/Carpet/CarpetLib/src/gh.hh b/Carpet/CarpetLib/src/gh.hh
index 4d1592120..0a283b4cf 100644
--- a/Carpet/CarpetLib/src/gh.hh
+++ b/Carpet/CarpetLib/src/gh.hh
@@ -96,6 +96,11 @@ public:
     return regions.AT(0).AT(rl).AT(c).processor;
   }
 
+  int old_processor (const int rl, const int c) const
+  {
+    return oldregions.AT(0).AT(rl).AT(c).processor;
+  }
+
   int mglevels () const
   {
     return (int)regions.size();