From c6e595e7fbbe80c8db7ae33d8af05a4fd946a2f5 Mon Sep 17 00:00:00 2001
From: Marc Mutz <marc.mutz@qt.io>
Date: Tue, 21 Dec 2021 09:20:17 +0100
Subject: [PATCH 17/20] QQmlJs::FixedPoolArray: fix UB (precondition violation)
 in allocate()

Says ubsan:

  qqmljsfixedpoolarray_p.h:90:19: runtime error: null pointer passed as argument 2, which is declared to never be null

Fix, like in so many other places, by a size check.

Pick-to: 6.3 6.2 5.15
Change-Id: I9181d6ecb467c2dc726978ce7f93b35a6bf2f944
Reviewed-by: Lars Knoll <lars.knoll@qt.io>
(cherry picked from commit d74e931f3fc2587ac6d1e2930acbbe54ea5be2b5)
---
 src/qml/common/qqmljsfixedpoolarray_p.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/qml/common/qqmljsfixedpoolarray_p.h b/src/qml/common/qqmljsfixedpoolarray_p.h
index b65b994d6c..15a8cd6878 100644
--- a/src/qml/common/qqmljsfixedpoolarray_p.h
+++ b/src/qml/common/qqmljsfixedpoolarray_p.h
@@ -86,7 +86,7 @@ public:
         if (QTypeInfo<T>::isComplex) {
             for (int i = 0; i < count; ++i)
                 new (data + i) T(vector.at(i));
-        } else {
+        } else if (count) {
             memcpy(data, static_cast<const void*>(vector.constData()), count * sizeof(T));
         }
     }
-- 
2.35.1