File lammps-allow-system-gtest.patch of Package lammps

---
 unittest/CMakeLists.txt |   41 +++++++++++++++++++++++++----------------
 1 file changed, 25 insertions(+), 16 deletions(-)

Index: lammps-stable_29Aug2024_update2/unittest/CMakeLists.txt
===================================================================
--- lammps-stable_29Aug2024_update2.orig/unittest/CMakeLists.txt
+++ lammps-stable_29Aug2024_update2/unittest/CMakeLists.txt
@@ -9,24 +9,33 @@ if((CMAKE_CXX_COMPILER_ID STREQUAL "GNU"
   message(FATAL_ERROR "Need GNU C++ compiler version 6.x or later for unit testing")
 endif()
 
-message(STATUS "Downloading and building googletest framework")
-set(GTEST_URL "https://github.com/google/googletest/archive/release-1.12.1.tar.gz" CACHE STRING "URL of googletest source")
-set(GTEST_MD5 "e82199374acdfda3f425331028eb4e2a" CACHE STRING "MD5 sum for googletest source")
-mark_as_advanced(GTEST_URL)
-mark_as_advanced(GTEST_MD5)
-set(gtest_force_shared_crt ON CACHE BOOL "" FORCE)
+set(EXTERNAL_GTEST OFF CACHE BOOL "Use system gtest")
+if (EXTERNAL_GTEST)
+  find_package(GTest REQUIRED)
+  add_library(GTest::GTest ALIAS GTest::gtest)
+  add_library(GTest::GMock ALIAS GTest::gmock)
+  add_library(GTest::GTestMain ALIAS GTest::gtest_main)
+  add_library(GTest::GMockMain ALIAS GTest::gmock_main)
+else()
+  message(STATUS "Downloading and building googletest framework")
+  set(GTEST_URL "https://github.com/google/googletest/archive/release-1.12.1.tar.gz" CACHE STRING "URL of googletest source")
+  set(GTEST_MD5 "e82199374acdfda3f425331028eb4e2a" CACHE STRING "MD5 sum for googletest source")
+  mark_as_advanced(GTEST_URL)
+  mark_as_advanced(GTEST_MD5)
+  set(gtest_force_shared_crt ON CACHE BOOL "" FORCE)
 
-include(ExternalCMakeProject)
-if(CMAKE_CXX_COMPILER_ID STREQUAL "IntelLLVM")
-  set(cxx_strict_flags "-Wno-error -Wno-unused-command-line-argument")
+  include(ExternalCMakeProject)
+  if(CMAKE_CXX_COMPILER_ID STREQUAL "IntelLLVM")
+    set(cxx_strict_flags "-Wno-error -Wno-unused-command-line-argument")
+  endif()
+  set(INSTALL_GTEST OFF CACHE BOOL "" FORCE)
+  set(INSTALL_GMOCK OFF CACHE BOOL "" FORCE)
+  ExternalCMakeProject(googletest ${GTEST_URL} ${GTEST_MD5} googletest . "")
+  add_library(GTest::GTest ALIAS gtest)
+  add_library(GTest::GMock ALIAS gmock)
+  add_library(GTest::GTestMain ALIAS gtest_main)
+  add_library(GTest::GMockMain ALIAS gmock_main)
 endif()
-set(INSTALL_GTEST OFF CACHE BOOL "" FORCE)
-set(INSTALL_GMOCK OFF CACHE BOOL "" FORCE)
-ExternalCMakeProject(googletest ${GTEST_URL} ${GTEST_MD5} googletest . "")
-add_library(GTest::GTest ALIAS gtest)
-add_library(GTest::GMock ALIAS gmock)
-add_library(GTest::GTestMain ALIAS gtest_main)
-add_library(GTest::GMockMain ALIAS gmock_main)
 
 option(SKIP_DEATH_TESTS "Do not run 'death tests' to reduce false positives in valgrind" OFF)
 mark_as_advanced(SKIP_DEATH_TESTS)