From 97a6b89f150c0ab616f5c0153a324057acdbe31b Mon Sep 17 00:00:00 2001
From: Nick Tustison <ntustison@gmail.com>
Date: Tue, 25 Jul 2023 19:00:36 -0700
Subject: [PATCH] BUG:  Avoid divide by 0.

---
 Examples/itkantsRegistrationHelper.hxx | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/Examples/itkantsRegistrationHelper.hxx b/Examples/itkantsRegistrationHelper.hxx
index 3ca3dd3ee..f496805d9 100644
--- a/Examples/itkantsRegistrationHelper.hxx
+++ b/Examples/itkantsRegistrationHelper.hxx
@@ -3712,9 +3712,16 @@ RegistrationHelper<TComputeType, VImageDimension>::CalculateMeshSizeForSpecified
 
   for (unsigned int d = 0; d < ImageDimension; d++)
   {
+    if (itk::Math::FloatAlmostEqual(knotSpacing, itk::NumericTraits<PixelType>::ZeroValue()))
+    {
+    meshSize.push_back(itk::NumericTraits<unsigned int>::ZeroValue());
+    }
+    else
+    {
     RealType domain = static_cast<RealType>(inputImage->GetLargestPossibleRegion().GetSize()[d] - 1) *
                       static_cast<RealType>(inputImage->GetSpacing()[d]);
     meshSize.push_back(static_cast<unsigned int>(std::ceil(domain / knotSpacing)));
+    }
     //     unsigned long extraPadding = static_cast<unsigned long>(
     //       ( numberOfSpans * splineDistance - domain ) / inputImage->GetSpacing()[d] + 0.5 );
     //     lowerBound[d] = static_cast<unsigned long>( 0.5 * extraPadding );