Fix for PR3946, in which SmallVector could behave strangely in corner cases.

Patch by Peter Johnson.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@69785 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/include/llvm/ADT/SmallVector.h b/include/llvm/ADT/SmallVector.h
index d5fef4828e612e58150d85a79c3971359da2722e..bf4960ad1445a6e6c3093bfb06824d0ff4f94442 100644 (file)
--- a/include/llvm/ADT/SmallVector.h
+++ b/include/llvm/ADT/SmallVector.h
@@ -302,7 +302,7 @@ public:
       append(End-NumToInsert, End);
 
       // Copy the existing elements that get replaced.
-      std::copy(I, OldEnd-NumToInsert, I+NumToInsert);
+      std::copy_backward(I, OldEnd-NumToInsert, OldEnd);
 
       std::fill_n(I, NumToInsert, Elt);
       return I;
@@ -351,7 +351,7 @@ public:
       append(End-NumToInsert, End);
 
       // Copy the existing elements that get replaced.
-      std::copy(I, OldEnd-NumToInsert, I+NumToInsert);
+      std::copy_backward(I, OldEnd-NumToInsert, OldEnd);
 
       std::copy(From, To, I);
       return I;