Merge remote-tracking branch 'origin/5.10' into dev

 Conflicts:
	src/corelib/global/minimum-linux.S
	src/network/access/qhttpthreaddelegate.cpp
	src/widgets/kernel/qwidgetwindow.cpp

Change-Id: Id2e817e85f85c68f5482c9a12912d35590f9d5f8

1 files changed, 7 insertions, 0 deletions

diff --git a/src/corelib/thread/qthread.cpp b/src/corelib/thread/qthread.cpp
index e92be64dfa..cad7a14017 100644
--- a/src/corelib/thread/qthread.cpp
+++ b/src/corelib/thread/qthread.cpp
@@ -78,6 +78,13 @@ QThreadData::~QThreadData()
        QThreadData::clearCurrentThreadData();
     }
 
+    // ~QThread() sets thread to nullptr, so if it isn't null here, it's
+    // because we're being run before the main object itself. This can only
+    // happen for QAdoptedThread. Note that both ~QThreadPrivate() and
+    // ~QObjectPrivate() will deref this object again, but that is acceptable
+    // because this destructor is still running (the _ref sub-object has not
+    // been destroyed) and there's no reentrancy. The refcount will become
+    // negative, but that's acceptable.
     QThread *t = thread;
     thread = 0;
     delete t;