Avoid the crash we get with this combination. Having identified the real
cause would of course have been better. But it seems no one has a clue.
size_t const n = slices_.size();
slices_.resize(0);
for (size_t i = 0 ; i < n; ++i) {
+ if (dit[i].empty() && prevMath().lyxCode() == MATH_SCRIPT_CODE)
+ // Workaround: With empty optional argument and a trailing script,
+ // we have empty slices in math macro args (#11676)
+ // FIXME: Find real cause!
+ continue;
LBUFERR(inset);
push_back(dit[i]);
top().inset_ = inset;