cmake: do not store `MINGW64_VERSION` in cache

Follow-up to e49797abc24b8e0ac652d7aa0ceec7d252f9a019 #16022
Closes #16040

diff --git a/CMakeLists.txt b/CMakeLists.txt
index a7b1fe5e3d0770edd1ee099e8df3737ea6b398a8..ce22cba5afaaf5af63de142aa1bf48033d9718cc 100644 (file)
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -225,16 +225,17 @@ if(WIN32)
     string(TOLOWER "${CURL_TEST_OUTPUT}" HAVE_WIN32_WINNT)
     message(STATUS "Found _WIN32_WINNT=${HAVE_WIN32_WINNT}")
   endif()
-  # Avoid storing HAVE_WIN32_WINNT in CMake cache
-  unset(HAVE_WIN32_WINNT CACHE)
+  unset(HAVE_WIN32_WINNT CACHE)  # Avoid storing in CMake cache
 
   if(MINGW)
+    # Detect __MINGW64_VERSION_MAJOR, __MINGW64_VERSION_MINOR and store as MINGW64_VERSION
     curl_internal_test(MINGW64_VERSION)
     if(MINGW64_VERSION)
       string(REGEX MATCH "MINGW64_VERSION=[0-9]+\.[0-9]+" CURL_TEST_OUTPUT "${CURL_TEST_OUTPUT}")
       string(REGEX REPLACE "MINGW64_VERSION=" "" MINGW64_VERSION "${CURL_TEST_OUTPUT}")
       message(STATUS "Found MINGW64_VERSION=${MINGW64_VERSION}")
     endif()
+    unset(MINGW64_VERSION CACHE)  # Avoid storing in CMake cache
   endif()
 elseif(DOS OR AMIGA)
   set(BUILD_SHARED_LIBS OFF)