Make QSharedPointer without custom deleters call the correct destructor

Where "correct" is defined by what std::shared_ptr does as well as what
happens when an intermediate QSharedPointer of the exact type of the
constructor behaves

That is,
   QSharedPointer<X> ptr(new Y);

Behaves like
   QSharedPointer<X> ptr;
   { QSharedPointer<Y> tmp(new Y); ptr = tmp; }

Change-Id: Id75834dab9ed466e94c7ffff14455d445f72592b
Reviewed-by: Olivier Goffart (Woboq GmbH) <ogoffart@woboq.com>
Reviewed-by: Marc Mutz <marc.mutz@kdab.com>

1 files changed, 8 insertions, 0 deletions

diff --git a/src/corelib/tools/qsharedpointer.cpp b/src/corelib/tools/qsharedpointer.cpp
index f420c6237b..c369ff8697 100644
--- a/src/corelib/tools/qsharedpointer.cpp
+++ b/src/corelib/tools/qsharedpointer.cpp
@@ -447,6 +447,11 @@
     Creates a QSharedPointer that points to \a ptr. The pointer \a ptr
     becomes managed by this QSharedPointer and must not be passed to
     another QSharedPointer object or deleted outside this object.
+
+    Since Qt 5.8, when the last reference to this QSharedPointer gets
+    destroyed, \a ptr will be deleted by calling \c X's destructor (even if \c
+    X is not the same as QSharedPointer's template parameter \c T). Previously,
+    the destructor for \c T was called.
 */
 
 /*!
@@ -477,6 +482,9 @@
     }
     \endcode
 
+    Note that the custom deleter function will be called with a pointer to type
+    \c X, even if the QSharedPointer template parameter \c T is not the same.
+
     It is also possible to specify a member function directly, as in:
     \code
         QSharedPointer<MyObject> obj =