Add option to turn off internal object Destroy for proxies, and add

documentation indicating why this might be necessary. For no though
leave it active until we find cases where this might need to change.

src/Infrastructure/Field/src/ESMF_FieldCreate.cppF90

@@ -5363,9 +5363,17 @@ type(ESMF_KeywordEnforcer), optional:: keywordEnforcer ! must use keywords below
         if (ftype%is_proxy .or. ftype%geomb_internal) then
 
           if (ftype%is_proxy) then
-            ! proxies destroy their actual geometry object, but must leave
+#if 1
+!gjt: Destroying geom object for proxies might not be a good idea. If this
+!gjt: every cases issues, then we might want to disable it here.
+!gjt: Disable, because proxy geoms might be used outside the original the
+!gjt: proxy field... cannot destroy here, but instead must keep proxy the
+!gjt: geom alive!!!
+
+            ! Proxies destroy their actual geometry object, but must leave
             ! in garbage collection because multiple fields might be referencing
-            ! the same actual geometry object, and try to destroy
+            ! the same actual geometry object, and try to destroy. Garbage
+            ! collection makes those double destroy calls safe noops.
 
             call ESMF_GeomGet(ftype%geom, geomtype=geomtype, rc=localrc)
             if (ESMF_LogFoundError(localrc, &
@@ -5421,14 +5429,19 @@ type(ESMF_KeywordEnforcer), optional:: keywordEnforcer ! must use keywords below
                 ESMF_CONTEXT, rcToReturn=rc)
               return
             endif
-
+            ! the Geom needs to be destroyed
+            call ESMF_GeomDestroy(ftype%geom, rc=localrc)
+            if (ESMF_LogFoundError(localrc, &
+              ESMF_ERR_PASSTHRU, &
+              ESMF_CONTEXT, rcToReturn=rc)) return
+#endif
+          else
+            ! the Geom needs to be destroyed
+            call ESMF_GeomDestroy(ftype%geom, rc=localrc)
+            if (ESMF_LogFoundError(localrc, &
+              ESMF_ERR_PASSTHRU, &
+              ESMF_CONTEXT, rcToReturn=rc)) return
           endif
-
-          ! proxy or not, the Geom needs to be destroyed
-          call ESMF_GeomDestroy(ftype%geom, rc=localrc)
-          if (ESMF_LogFoundError(localrc, &
-            ESMF_ERR_PASSTHRU, &
-            ESMF_CONTEXT, rcToReturn=rc)) return
         endif
 
         ftype%status = ESMF_FIELDSTATUS_UNINIT  ! mark invalid