Fix PR#35119 : set_union misbehaves with move_iterators. Thanks to Denis Yaroshevskiy for both the bug report and the fix.

llvm-svn: 316914

1 files changed, 1 insertions, 1 deletions

diff --git a/libcxx/include/algorithm b/libcxx/include/algorithm
index 282083a89c2..f5776b40400 100644
--- a/libcxx/include/algorithm
+++ b/libcxx/include/algorithm
@@ -5547,9 +5547,9 @@ __set_union(_InputIterator1 __first1, _InputIterator1 __last1,
         }
         else
         {
-            *__result = *__first1;
             if (!__comp(*__first1, *__first2))
                 ++__first2;
+            *__result = *__first1;
             ++__first1;
         }
     }