From c6755a399e8a31cbee5129dde5124f9c54a47ab6 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Nikola=20Forr=C3=B3?= <nforro@redhat.com>
Date: Wed, 4 Apr 2018 14:58:03 +0200
Subject: [PATCH] Do not call back() on an empty vector
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Calling std::vector::back() on an empty container is undefined.
Avoid doing that, simply return pointer to the beginning in case
the vector is empty.

Signed-off-by: Nikola Forró <nforro@redhat.com>
---
 common/vector.hpp | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/common/vector.hpp b/common/vector.hpp
index 782e4b0..cb344bd 100644
--- a/common/vector.hpp
+++ b/common/vector.hpp
@@ -36,13 +36,13 @@ namespace acommon
     }
     T * data() {return &*this->begin();}
     T * data(int pos) {return &*this->begin() + pos;}
-    T * data_end() {return &this->back()+1;}
+    T * data_end() {return this->empty() ? &*this->begin() : &this->back()+1;}
 
     T * pbegin() {return &*this->begin();}
-    T * pend()   {return &this->back()+1;}
+    T * pend()   {return this->empty() ? &*this->begin() : &this->back()+1;}
 
     const T * pbegin() const {return &*this->begin();}
-    const T * pend()   const {return &this->back()+1;}
+    const T * pend()   const {return this->empty() ? &*this->begin() : &this->back()+1;}
 
     template <typename U>
     U * datap() {