ofz#8330 Abrt, fallout from rework to use buffer

Change-Id: I9d4a70d8ae2f5247901c584dc05405665eac065b
Reviewed-on: https://gerrit.libreoffice.org/54525Reviewed-by: Caolán McNamara <caolanm@redhat.com>
Tested-by: Caolán McNamara <caolanm@redhat.com>

starmath/source/mathtype.cxx

@@ -2895,7 +2895,7 @@ bool MathType::HandleChar(sal_Int32 &rTextStart, int &rSetSize, int nLevel,
                 OUString aStr;
                 TypeFaceToString(aStr,nOldTypeFace);
                 aStr += "\"";
-                rRet.insert(rTextStart, aStr);
+                rRet.insert(std::min(rTextStart, rRet.getLength()), aStr);
 
                 aStr.clear();
                 TypeFaceToString(aStr,nTypeFace);