--- a/src/corelib/tools/qstring.cpp	Fri Apr 16 15:50:13 2010 +0300
+++ b/src/corelib/tools/qstring.cpp	Mon May 03 13:17:34 2010 +0300
@@ -3185,7 +3185,7 @@
         if (!empty || !(flags & SectionSkipEmpty))
             x++;
     }
-    if((flags & SectionIncludeLeadingSep)) {
+    if((flags & SectionIncludeLeadingSep) && first_i < sections.size()) {
         const qt_section_chunk &section = sections.at(first_i);
         ret.prepend(section.string.left(section.length));
     }