From 81a19050d8127e7b05006f793a8797c8f5248191 Mon Sep 17 00:00:00 2001
From: Giuseppe D'Angelo <giuseppe.dangelo@kdab.com>
Date: Tue, 12 Sep 2017 11:42:23 +0100
Subject: QSharedPointer: fix undefined behavior in operator<

Pointers belonging to different arrays must be compared using
std::less.

Change-Id: Ib77af7b1b2da58d7243fa77273a8a45ee9035a1a
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>
---
 src/corelib/tools/qsharedpointer_impl.h | 9 ++++++---
 1 file changed, 6 insertions(+), 3 deletions(-)

(limited to 'src/corelib/tools')

diff --git a/src/corelib/tools/qsharedpointer_impl.h b/src/corelib/tools/qsharedpointer_impl.h
index 15573c5588..ede54c155d 100644
--- a/src/corelib/tools/qsharedpointer_impl.h
+++ b/src/corelib/tools/qsharedpointer_impl.h
@@ -850,17 +850,20 @@ Q_INLINE_TEMPLATE typename QSharedPointer<X>::difference_type operator-(T *ptr1,
 template <class T, class X>
 Q_INLINE_TEMPLATE bool operator<(const QSharedPointer<T> &ptr1, const QSharedPointer<X> &ptr2)
 {
-    return ptr1.data() < ptr2.data();
+    using CT = typename std::common_type<T *, X *>::type;
+    return std::less<CT>()(ptr1.data(), ptr2.data());
 }
 template <class T, class X>
 Q_INLINE_TEMPLATE bool operator<(const QSharedPointer<T> &ptr1, X *ptr2)
 {
-    return ptr1.data() < ptr2;
+    using CT = typename std::common_type<T *, X *>::type;
+    return std::less<CT>()(ptr1.data(), ptr2);
 }
 template <class T, class X>
 Q_INLINE_TEMPLATE bool operator<(T *ptr1, const QSharedPointer<X> &ptr2)
 {
-    return ptr1 < ptr2.data();
+    using CT = typename std::common_type<T *, X *>::type;
+    return std::less<CT>()(ptr1, ptr2.data());
 }
 
 //
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