The forward iteration logic already bounds-check for m_it != m_string->end(),
do the same for the backward iteration. The issue with the assert is
that the assert() might not be compiled in, and it is happening after
the dereference, so it was too late.
For line-wrapping bytes were counted instead of codepoints. This
resulted in line-breaks being inserted at the wrong position and also
breaking UTF-8 characters.
Fixes#1022.
This PR adds functionality to skip around ANSI escape sequences in catch_textflow so they do not contribute to line length and line wrapping code does not split escape sequences in the middle. I've implemented this by creating a AnsiSkippingString abstraction that has a bidirectional iterator that can skip around escape sequences while iterating. Additionally I refactored Column::const_iterator to be iterator-based rather than index-based so this abstraction is a simple drop-in for std::string.
Currently only color sequences are handled, other escape sequences are left unaffected.
Motivation: Text with ANSI color sequences gets messed up when being output by Catch2 #2833.
Dirk Müller
Jan Niklas Hasse
Jeremy Rifkin
Martin Jeřábek
Lars Toenning
Martin Hořeňovský