[libc++] random_device fails if open returns zero

random_device::random_device(const string&) wrongly assumes that open
can only validly return a file descriptor greater than zero.

This results in random_device believing that it didn't successfully open
the device causing it to throw in it's constructor, this ends up leaking
a file descriptor.

The fix is simple, don't error on file descriptors which are zero.

llvm-svn: 210060

1 files changed, 1 insertions, 1 deletions

diff --git a/libcxx/src/random.cpp b/libcxx/src/random.cpp
index bd24f2e50c1..21e21689a87 100644
--- a/libcxx/src/random.cpp
+++ b/libcxx/src/random.cpp
@@ -49,7 +49,7 @@ random_device::operator()()
 random_device::random_device(const string& __token)
     : __f_(open(__token.c_str(), O_RDONLY))
 {
-    if (__f_ <= 0)
+    if (__f_ < 0)
         __throw_system_error(errno, ("random_device failed to open " + __token).c_str());
 }