[KevinH]

Okay I checked src/Exporters/NCXWriter.cpp

and we use:

m_Writer->writeAttribute("id", QString("navPoint-%1").arg(play_order));

So guaranteed to not begin with a digit.

We do similar things in python3lib/ncxgenerator.py so our auto conversion routines from nav to ncx should be fine there.

I also checked the nav for epub3: src/ResourceObjects/NavProcessor.cpp
and it does not use "id" in a similar manner so we are okay there as well.

I did see lots of calls to Gumbo's get_local_text_of_node() and there are no calls to simplified so we should probably add some simplify calls to the NavProcessor.cpp every time we use get_local_text_of_node just to be safe. That said a newline in an html document will just become a space and multiple spaces are condensed in html, so for the nav this may not matter too much.