fix segfault on fb platform

Summary: Strings can be moved around while the vector grows.

Test Plan: file_util_test

Reviewed By: lucian@fb.com

FB internal diff: D806966

Blame Revision: D806781

diff --git a/folly/test/FileUtilTest.cpp b/folly/test/FileUtilTest.cpp
index 8b50b5cfd2feb76f64767b1737c9ac2487e06ad9..f9fe52b7e3f6e8bf52e578faa25a29ddf2b66af3 100644 (file)
--- a/folly/test/FileUtilTest.cpp
+++ b/folly/test/FileUtilTest.cpp
@@ -192,9 +192,11 @@ IovecBuffers::IovecBuffers(std::initializer_list<size_t> sizes) {
   iov_.reserve(sizes.size());
   for (auto& s : sizes) {
     buffers_.push_back(std::string(s, '\0'));
+  }
+  for (auto& b : buffers_) {
     iovec iov;
-    iov.iov_base = &(buffers_.back()[0]);
-    iov.iov_len = s;
+    iov.iov_base = &b[0];
+    iov.iov_len = b.size();
     iov_.push_back(iov);
   }
 }