From 0a363faafb5c951499b47fc9fc1b930b78501eac Mon Sep 17 00:00:00 2001
From: Niels Dekker <N.Dekker@lumc.nl>
Date: Fri, 28 Nov 2025 18:14:13 +0100
Subject: [PATCH] BUG: Let DataObjectError override `ExceptionObject::Print`

Instead of introducing a new virtual member function,
`DataObjectError::PrintSelf`.

It is essential that DataObjectError overrides `ExceptionObject::Print`, because
that is the member function that is called, when doing `std::cerr << error` for
a DataObjectError.

- Fixes issue https://github.com/InsightSoftwareConsortium/ITK/issues/5666
"DataObjectError print to output stream should also print info about its DataObject"
---
 Modules/Core/Common/include/itkDataObject.h | 12 ++----------
 Modules/Core/Common/src/itkDataObject.cxx   | 10 +++-------
 2 files changed, 5 insertions(+), 17 deletions(-)

diff --git a/Modules/Core/Common/include/itkDataObject.h b/Modules/Core/Common/include/itkDataObject.h
index 26811fd85aa..b08d3a2cd42 100644
--- a/Modules/Core/Common/include/itkDataObject.h
+++ b/Modules/Core/Common/include/itkDataObject.h
@@ -90,8 +90,8 @@ class ITKCommon_EXPORT DataObjectError : public ExceptionObject
    * specific exception subtypes.  The default is to print out the
    * location where the exception was first thrown and any description
    * provided by the "thrower".   */
-  virtual void
-  PrintSelf(std::ostream & os, Indent indent) const;
+  void
+  Print(std::ostream & os) const override;
 
 private:
   DataObject * m_DataObject{ nullptr };
@@ -126,14 +126,6 @@ class ITKCommon_EXPORT InvalidRequestedRegionError : public DataObjectError
 
   /** \see LightObject::GetNameOfClass() */
   itkOverrideGetNameOfClassMacro(InvalidRequestedRegionError);
-
-protected:
-  /** Print exception information.  This method can be overridden by
-   * specific exception subtypes.  The default is to print out the
-   * location where the exception was first thrown and any description
-   * provided by the "thrower".   */
-  void
-  PrintSelf(std::ostream & os, Indent indent) const override;
 };
 
 /*----------------------------Data Object--------------------------------*/
diff --git a/Modules/Core/Common/src/itkDataObject.cxx b/Modules/Core/Common/src/itkDataObject.cxx
index edab7cb616f..5a9c70fc694 100644
--- a/Modules/Core/Common/src/itkDataObject.cxx
+++ b/Modules/Core/Common/src/itkDataObject.cxx
@@ -70,10 +70,12 @@ DataObjectError::GetDataObject() const noexcept
 
 
 void
-DataObjectError::PrintSelf(std::ostream & os, Indent indent) const
+DataObjectError::Print(std::ostream & os) const
 {
   ExceptionObject::Print(os);
 
+  const Indent indent{};
+
   os << indent << "Data object: ";
   if (m_DataObject)
   {
@@ -99,12 +101,6 @@ InvalidRequestedRegionError::InvalidRequestedRegionError(const InvalidRequestedR
 InvalidRequestedRegionError &
 InvalidRequestedRegionError::operator=(const InvalidRequestedRegionError &) noexcept = default;
 
-void
-InvalidRequestedRegionError::PrintSelf(std::ostream & os, Indent indent) const
-{
-  DataObjectError::PrintSelf(os, indent);
-}
-
 //----------------------------------------------------------------------------
 DataObject::DataObject()
   : m_SourceOutputName("")