fix-myrocks-build.diff

diff --git a/CMakeLists.txt b/CMakeLists.txt
index b1ad256a4af..11119e496c5 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -369,6 +369,7 @@ INCLUDE(configure.cmake)
 
 # Always use USE_MYSYS_NEW
 ADD_DEFINITIONS(-DUSE_MYSYS_NEW)
+SET(USING_MYSYS_NEW ON)
 
 # Find header files from the bundled libraries
 # (wolfssl, readline, pcre2, etc)
diff --git a/storage/rocksdb/build_rocksdb.cmake b/storage/rocksdb/build_rocksdb.cmake
index 5047e073751..fe7c453498d 100644
--- a/storage/rocksdb/build_rocksdb.cmake
+++ b/storage/rocksdb/build_rocksdb.cmake
@@ -148,7 +148,7 @@ int main() {
 endif()
 
 CHECK_FUNCTION_EXISTS(malloc_usable_size HAVE_MALLOC_USABLE_SIZE)
-if(HAVE_MALLOC_USABLE_SIZE)
+if(HAVE_MALLOC_USABLE_SIZE AND NOT USING_MYSYS_NEW)
   add_definitions(-DROCKSDB_MALLOC_USABLE_SIZE)
 endif()