From 57e5f81869b966425c4b1947664a330f5d20180e Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Jon=20Haitz=20Legarreta=20Gorro=C3=B1o?=
 <jon.haitz.legarreta@gmail.com>
Date: Mon, 8 Mar 2021 20:53:15 -0500
Subject: [PATCH] COMP: Fix image pointer casting error

Fix image pointer casting error.

Fixes
```
In file included from
ITK/Modules/Core/FiniteDifference/include/itkDenseFiniteDifferenceImageFilter.h:194:0,
from
ITK/Modules/Filtering/AnisotropicSmoothing/include/itkAnisotropicDiffusionImageFilter.h:21,
from
ITK/Modules/Filtering/AnisotropicSmoothing/include/itkGradientAnisotropicDiffusionImageFilter.h:21,
from
src/Filtering/AnisotropicSmoothing/ComputePeronaMalikAnisotropicDiffusion/Code.cxx:22:
/.../ITKExamples-build/ITK/Modules/Core/FiniteDifference/include/itkDenseFiniteDifferenceImageFilter.hxx:
In instantiation of
'void itk::DenseFiniteDifferenceImageFilter<TInputImage, TOutputImage>::CopyInputToOutput()
[with TInputImage = itk::Image<unsigned char, 2>; TOutputImage = itk::Image<float, 2>]':
src/Filtering/AnisotropicSmoothing/ComputePeronaMalikAnisotropicDiffusion/Code.cxx:72:1:
required from here

ITK/Modules/Core/FiniteDifference/include/itkDenseFiniteDifferenceImageFilter.hxx:44:35:
error: conversion from 'itk::SmartPointer<itk::Image<float, 2> >::ObjectType*
{aka itk::Image<float, 2>*}' to non-scalar type
'itk::Image<unsigned char, 2>::Pointer
{aka itk::SmartPointer<itk::Image<unsigned char, 2> >}' requested

typename TInputImage::Pointer tempPtr =	output.GetPointer();
                              ^~~~~~~
```

raised at:
https://open.cdash.org/viewBuildError.php?buildid=7083938
---
 .../include/itkDenseFiniteDifferenceImageFilter.hxx          | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/Modules/Core/FiniteDifference/include/itkDenseFiniteDifferenceImageFilter.hxx b/Modules/Core/FiniteDifference/include/itkDenseFiniteDifferenceImageFilter.hxx
index 5fee42115eb..f4614b90250 100644
--- a/Modules/Core/FiniteDifference/include/itkDenseFiniteDifferenceImageFilter.hxx
+++ b/Modules/Core/FiniteDifference/include/itkDenseFiniteDifferenceImageFilter.hxx
@@ -41,8 +41,9 @@ DenseFiniteDifferenceImageFilter<TInputImage, TOutputImage>::CopyInputToOutput()
   // Check if we are doing in-place filtering
   if (this->GetInPlace() && this->CanRunInPlace())
   {
-    typename TInputImage::Pointer tempPtr = output.GetPointer();
-    if (tempPtr && tempPtr->GetPixelContainer() == input->GetPixelContainer())
+    const void * const inputPixelContainer = input->GetPixelContainer();
+    const auto * const tempPtr = output.GetPointer();
+    if (tempPtr != nullptr && tempPtr->GetPixelContainer() == inputPixelContainer)
     {
       // the input and output container are the same - no need to copy
       return;