1 files changed, 16 insertions, 1 deletions
diff --git a/include/oox/helper/helper.hxx b/include/oox/helper/helper.hxx
index 5a83c3780bc8..168116b9db84 100644
--- a/include/oox/helper/helper.hxx
+++ b/include/oox/helper/helper.hxx
@@ -25,6 +25,7 @@
 #include <cstring>
 #include <limits>
 
+#include <o3tl/safeint.hxx>
 #include <osl/endian.h>
 #include <rtl/math.hxx>
 #include <rtl/textenc.h>
@@ -36,10 +37,24 @@ namespace oox {
 
 // Helper macros ==============================================================
 
+namespace detail {
+
+//TODO: Temporary helper for STATIC_ARRAY_SELECT; ultimately, the latter should be replaced by a
+// proper function (template):
+template<typename T> constexpr std::make_unsigned_t<T> make_unsigned(T value) {
+    if constexpr (std::is_signed_v<T>) {
+        return o3tl::make_unsigned(value);
+    } else {
+        return value;
+    }
+}
+
+}
+
 /** Expands to the 'index'-th element of a STATIC data array, or to 'def', if
     'index' is out of the array limits. */
 #define STATIC_ARRAY_SELECT( array, index, def ) \
-    ((static_cast<size_t>(index) < SAL_N_ELEMENTS(array)) ? ((array)[static_cast<size_t>(index)]) : (def))
+    ((detail::make_unsigned(index) < SAL_N_ELEMENTS(array)) ? ((array)[static_cast<size_t>(index)]) : (def))
 
 // Common constants ===========================================================