OpenEXR 3 fixes from Arch Linux

Due to lack of time, we apply the patch conditionally only on F35+.

prusa-slicer-openexr3.patch

@@ -0,0 +1,77 @@
+diff --git a/cmake/modules/FindOpenVDB.cmake b/cmake/modules/FindOpenVDB.cmake
+index 02420fed8..4b93111ab 100644
+--- a/cmake/modules/FindOpenVDB.cmake
++++ b/cmake/modules/FindOpenVDB.cmake
+@@ -326,28 +326,10 @@ macro(just_fail msg)
+   return()
+ endmacro()
+ 
+-find_package(IlmBase QUIET COMPONENTS Half)
+-if(NOT IlmBase_FOUND)
+-  pkg_check_modules(IlmBase QUIET IlmBase)
+-endif()
+-if (IlmBase_FOUND AND NOT TARGET IlmBase::Half)
+-  message(STATUS "Falling back to IlmBase found by pkg-config...")
+-
+-  find_library(IlmHalf_LIBRARY NAMES Half)
+-  if(IlmHalf_LIBRARY-NOTFOUND OR NOT IlmBase_INCLUDE_DIRS)
+-    just_fail("IlmBase::Half can not be found!")
+-  endif()
+-  
+-  add_library(IlmBase::Half UNKNOWN IMPORTED)
+-  set_target_properties(IlmBase::Half PROPERTIES
+-    IMPORTED_LOCATION "${IlmHalf_LIBRARY}"
+-    INTERFACE_INCLUDE_DIRECTORIES "${IlmBase_INCLUDE_DIRS}")
+-elseif(NOT IlmBase_FOUND)
+-  just_fail("IlmBase::Half can not be found!")
+-endif()
+ find_package(TBB ${_quiet} ${_required} COMPONENTS tbb)
+ find_package(ZLIB ${_quiet} ${_required})
+ find_package(Boost ${_quiet} ${_required} COMPONENTS iostreams system )
++find_package(Imath CONFIG)
+ 
+ # Use GetPrerequisites to see which libraries this OpenVDB lib has linked to
+ # which we can query for optional deps. This basically runs ldd/otoll/objdump
+@@ -398,7 +380,7 @@ foreach(PREREQUISITE ${_OPENVDB_PREREQUISITE_LIST})
+     set(OpenVDB_USES_LOG4CPLUS ON)
+   endif()
+ 
+-  string(FIND ${PREREQUISITE} "IlmImf" _HAS_DEP)
++  string(FIND ${PREREQUISITE} "OpenEXR" _HAS_DEP)
+   if(NOT ${_HAS_DEP} EQUAL -1)
+     set(OpenVDB_USES_ILM ON)
+   endif()
+@@ -429,11 +411,7 @@ if(OpenVDB_USES_LOG4CPLUS)
+   find_package(Log4cplus ${_quiet} ${_required})
+ endif()
+ 
+-if(OpenVDB_USES_ILM)
+-  find_package(IlmBase ${_quiet} ${_required})
+-endif()
+-
+-if(OpenVDB_USES_EXR)
++if(OpenVDB_USES_ILM OR OpenVDB_USES_EXR)
+   find_package(OpenEXR ${_quiet} ${_required})
+ endif()
+ 
+@@ -450,7 +428,7 @@ endif()
+ set(_OPENVDB_VISIBLE_DEPENDENCIES
+   Boost::iostreams
+   Boost::system
+-  IlmBase::Half
++  Imath::Imath
+ )
+ 
+ set(_OPENVDB_DEFINITIONS)
+@@ -460,10 +438,7 @@ endif()
+ 
+ if(OpenVDB_USES_EXR)
+   list(APPEND _OPENVDB_VISIBLE_DEPENDENCIES
+-    IlmBase::IlmThread
+-    IlmBase::Iex
+-    IlmBase::Imath
+-    OpenEXR::IlmImf
++    OpenEXR::OpenEXR
+   )
+   list(APPEND _OPENVDB_DEFINITIONS "-DOPENVDB_TOOLS_RAYTRACER_USE_EXR")
+ endif()

prusa-slicer.spec

@@ -8,7 +8,7 @@
 
 Name:           prusa-slicer
 Version:        2.3.1
-Release:        3%{?dist}
+Release:        4%{?dist}
 Summary:        3D printing slicer optimized for Prusa printers
 
 # The main PrusaSlicer code and resources are AGPLv3, with small parts as
@@ -33,6 +33,15 @@ Patch1:         optional.patch
 # https://github.com/prusa3d/PrusaSlicer/pull/6518
 Patch2:         0001-Fix-build-error-with-non-const-MINSIGSTKSZ.patch
 
+
+# Beware!
+# Patches >= 340 are only applied on Fedora 34+
+# Patches >= 350 are only applied on Fedora 35+
+# ...
+
+# OpenEXR 3 fixes
+Patch351:       https://github.com/archlinux/svntogit-community/blob/1dea61c0b5/trunk/prusa-slicer-openexr3.patch
+
 # Highly-parallel uild can run out of memory on PPC64le
 %ifarch ppc64le
 %global _smp_ncpus_max 8
@@ -237,7 +246,9 @@ community.
 
 
 %prep
-%autosetup -S git -n PrusaSlicer-version_%version
+%autosetup -S git -n PrusaSlicer-version_%version -N
+# Apply patches, but only apply 340+ on Fedora 34, 350+ on Fedora 35, etc...
+%autopatch -M %[%{?fedora} * 10 + 9]
 
 commit () { git commit -q -a -m "$1" --author "%{__scm_author}"; }
 
@@ -415,6 +426,9 @@ rm -rf %buildroot%_datadir/PrusaSlicer/data/
 %endif
 
 %changelog
+* Mon Aug 02 2021 Miro Hrončok <mhroncok@redhat.com> - 2.3.1-4
+- Rebuilt for OpenEXR 3
+
 * Fri Jul 23 2021 Fedora Release Engineering <releng@fedoraproject.org> - 2.3.1-3
 - Rebuilt for https://fedoraproject.org/wiki/Fedora_35_Mass_Rebuild