fdo#77300: Do the same for the shared formula case as well.

Change-Id: I560b0beabe81907e3f85d8845041a9df25d2200d

sc/source/core/data/column4.cxx

@@ -637,6 +637,8 @@ public:
             ScFormulaCell* pTop = *rEntry.mpCells;
             OUString aFormula = pTop->GetHybridFormula();
 
+            if (!aFormula.isEmpty())
+            {
                 // Create a new token array from the hybrid formula string, and
                 // set it to the group.
                 ScCompiler aComp(mrCompileFormulaCxt, pTop->aPos);
@@ -656,6 +658,7 @@ public:
                     p->SetDirty();
                 }
             }
+        }
         else
         {
             ScFormulaCell* pCell = rEntry.mpCell;