corelib/tools: Fix auto detection of QOffsetStringArray::m_offset type

The previous implementation wrongly calculated the necessary data type
to hold the offset indexes. It looked at the amount of elements,
but instead we should look at value for the last element in the offset
array

Change-Id: I84c6985dc3c329df3bbc5a14f9789170877b65bb
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>

1 files changed, 9 insertions, 12 deletions

diff --git a/src/corelib/tools/qoffsetstringarray_p.h b/src/corelib/tools/qoffsetstringarray_p.h
index a1117b1d47..ff195965ec 100644
--- a/src/corelib/tools/qoffsetstringarray_p.h
+++ b/src/corelib/tools/qoffsetstringarray_p.h
@@ -62,26 +62,23 @@ namespace QtPrivate {
 template<int N, int O, int I, int ... Idx>
 struct OffsetSequenceHelper : OffsetSequenceHelper<N - 1, O + I, Idx..., O> { };
 
-template<int O, int I, int ... Idx>
-struct OffsetSequenceHelper<0, O, I, Idx...> : IndexesList<O, Idx...>
+template<int Last, int I, int S, int ... Idx>
+struct OffsetSequenceHelper<1, Last, I, S, Idx...> : IndexesList<Last + I, Idx..., Last>
 {
-    static const constexpr auto Length = O;
-};
-
-template<int I, int ... Idx>
-struct OffsetSequence : OffsetSequenceHelper<sizeof ... (Idx) + 1, 0, I, Idx..., 0>
-{
-    static const constexpr auto Count = sizeof ... (Idx) + 1;
+    static const constexpr auto Length = Last + I;
     using Type = typename QConditional<
-        Count <= std::numeric_limits<quint8>::max() + 1,
+        Last <= std::numeric_limits<quint8>::max(),
         quint8,
         typename QConditional<
-            Count <= std::numeric_limits<quint16>::max() + 1,
+            Last <= std::numeric_limits<quint16>::max(),
             quint16,
             int>::Type
         >::Type;
 };
 
+template<int ... Idx>
+struct OffsetSequence : OffsetSequenceHelper<sizeof ... (Idx), 0, Idx..., 0> { };
+
 template<int N>
 struct StaticString
 {
@@ -168,7 +165,7 @@ public:
     }
 
     constexpr inline const char *str() const { return m_string; }
-    constexpr inline const int *offsets() const { return m_offsets; }
+    constexpr inline const T *offsets() const { return m_offsets; }
     constexpr inline int count() const { return SizeOffsets; };
 
     static constexpr const auto sizeString = SizeString;