From 5c8b2d86d983c27865190d10265c9e65e3125aa6 Mon Sep 17 00:00:00 2001
From: Sean McBride <sean@rogue-research.com>
Date: Fri, 27 Dec 2024 10:29:28 -0500
Subject: [PATCH] BUG: move null check to *before* dereferencing

cppcheck warned:

nullPointerRedundantCheck,itkTimeVaryingVelocityFieldIntegrationImageFilter.hxx:67,warning,Either the condition '!input' is redundant or there is possible null pointer dereference: input.

There is a slight behaviour change now: `m_NumberOfTimePoints` is no longer set if `input` is provided and `output` is not.
---
 .../itkTimeVaryingVelocityFieldIntegrationImageFilter.hxx       | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/Modules/Filtering/DisplacementField/include/itkTimeVaryingVelocityFieldIntegrationImageFilter.hxx b/Modules/Filtering/DisplacementField/include/itkTimeVaryingVelocityFieldIntegrationImageFilter.hxx
index 7b90bbee857..8432264d3ec 100644
--- a/Modules/Filtering/DisplacementField/include/itkTimeVaryingVelocityFieldIntegrationImageFilter.hxx
+++ b/Modules/Filtering/DisplacementField/include/itkTimeVaryingVelocityFieldIntegrationImageFilter.hxx
@@ -64,11 +64,11 @@ TimeVaryingVelocityFieldIntegrationImageFilter<TTimeVaryingVelocityField,
 {
   const TimeVaryingVelocityFieldType * input = this->GetInput();
   DisplacementFieldType *              output = this->GetOutput();
-  this->m_NumberOfTimePoints = input->GetLargestPossibleRegion().GetSize()[OutputImageDimension];
   if (!input || !output)
   {
     return;
   }
+  this->m_NumberOfTimePoints = input->GetLargestPossibleRegion().GetSize()[OutputImageDimension];
 
   //
   // The ImageBase::CopyInformation() method ca not be used here