Fix sorting issue when sorting by "size"

Root cause of the issue was an overflow in:
result = a - b;
where result is 'int' and a and b are 'KIO::filesize_t'.

BUG: 293086
FIXED-IN: 4.8.1

1 files changed, 6 insertions, 0 deletions

diff --git a/src/kitemviews/kfileitemmodel.h b/src/kitemviews/kfileitemmodel.h
index ff816c85c..d819c3734 100644
--- a/src/kitemviews/kfileitemmodel.h
+++ b/src/kitemviews/kfileitemmodel.h
@@ -330,6 +330,12 @@ private:
      */
     KFileItemList childItems(const KFileItem& item) const;
 
+    /**
+     * Helper method for sortRoleCompare().
+     * @return 0 if both sizes are equal, +1 if a > b and -1 if a < b.
+     */
+    static int fileSizeCompare(KIO::filesize_t a, KIO::filesize_t b);
+
 private:
     QWeakPointer<KDirLister> m_dirLister;