[PATCH] cxx: do not create chip if gpiod_chip_iter_next_noclose return nullptr

[Patrick Boettcher <p@xxxxxx>]

As a shared-ptr deleter is called even
if ptr is nullptr

fixes #35

Signed-off-by: Patrick Boettcher <p@xxxxxx>
---
 bindings/cxx/iter.cpp | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/bindings/cxx/iter.cpp b/bindings/cxx/iter.cpp
index 0f11057..16ce0cd 100644
--- a/bindings/cxx/iter.cpp
+++ b/bindings/cxx/iter.cpp
@@ -58,10 +58,12 @@ bool chip_iter::operator!=(const chip_iter& rhs) const noexcept
 }
 
 chip_iter::chip_iter(::gpiod_chip_iter *iter)
-	: _m_iter(iter, chip_iter_deleter),
-	  _m_current(chip(::gpiod_chip_iter_next_noclose(this->_m_iter.get())))
+	: _m_iter(iter, chip_iter_deleter)
 {
+	::gpiod_chip* first = ::gpiod_chip_iter_next_noclose(this->_m_iter.get());
 
+	if (first != nullptr)
+		this->_m_current = chip(first);
 }
 
 chip_iter& chip_iter::operator++(void)
-- 
2.20.1