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| author | Marshall Clow <mclow.lists@gmail.com> | 2016-06-04 16:16:59 +0000 |
|---|---|---|
| committer | Marshall Clow <mclow.lists@gmail.com> | 2016-06-04 16:16:59 +0000 |
| commit | e499d086aa2b7a7248ded3f406ebf19ef53ad6c2 (patch) | |
| tree | 0c5c03f667dcd8e2b077977cc145ec6ec4b3d868 | |
| parent | 8c46a4ceea5254c2d5716d1c3ed7a309697d9f96 (diff) | |
| download | bcm5719-llvm-e499d086aa2b7a7248ded3f406ebf19ef53ad6c2.tar.gz bcm5719-llvm-e499d086aa2b7a7248ded3f406ebf19ef53ad6c2.zip | |
Don't call memmove when there's nothing to move. Fixes PR#27978.
llvm-svn: 271794
| -rw-r--r-- | libcxx/include/fstream | 4 |
1 files changed, 3 insertions, 1 deletions
diff --git a/libcxx/include/fstream b/libcxx/include/fstream index d51da45d874..3cb3b13bd10 100644 --- a/libcxx/include/fstream +++ b/libcxx/include/fstream @@ -606,7 +606,9 @@ basic_filebuf<_CharT, _Traits>::underflow() } else { - memmove(__extbuf_, __extbufnext_, __extbufend_ - __extbufnext_); + _LIBCPP_ASSERT ( !(__extbufnext_ == NULL && (__extbufend_ != __extbufnext_)), "underflow moving from NULL" ); + if (__extbufend_ != __extbufnext_) + memmove(__extbuf_, __extbufnext_, __extbufend_ - __extbufnext_); __extbufnext_ = __extbuf_ + (__extbufend_ - __extbufnext_); __extbufend_ = __extbuf_ + (__extbuf_ == __extbuf_min_ ? sizeof(__extbuf_min_) : __ebs_); size_t __nmemb = _VSTD::min(static_cast<size_t>(__ibs_ - __unget_sz), |
