Multiline labels in math mode

[tkralphs]

The function is_multiline_label here is correctly detecting when a label is supposed to be considered multiline according to the graphviz format documented here, but this means that one cannot include any LaTex that begins with \l in a label name. For example, with -t math, the following graph isn't parsed the way I expect.

digraph G {
layout=dot;
d2tgraphstyle="every text node part/.style={align=center}";
0 -> 2  [label="x_{8} \leq 0"];
0 -> 3  [label="x_{8} \geq 1"];
2 -> 4  [label="x_{19} \leq 0"];
2 -> 5  [label="x_{19} \geq 1"];
5 -> 10  [label="x_{7} \leq 0"];
5 -> 11  [label="x_{7} \geq 1"];
3 -> 6  [label="x_{17} \leq 0"];
3 -> 7  [label="x_{17} \geq 1"];
10 -> 12  [label="x_{1} \leq 0"];
10 -> 13  [label="x_{1} \geq 1"];
11 -> 14  [label="x_{13} \leq 0"];
11 -> 15  [label="x_{13} \geq 1"];
7 -> 18  [label="x_{14} \leq 0"];
7 -> 19  [label="x_{14} \geq 1"];
4 -> 8  [label="x_{16} \leq 0"];
4 -> 9  [label="x_{16} \geq 1"];
}

The \leq is interpreted as indicating a multiline label with eq at the beginning of the second line, whereas I'm trying to render a "<=" sign in math mode.

I guess there is no perfect solution to this, since the dot syntax is in direct conflict with LaTex syntax on this. A flag indicating that the multiline detection should be skipped would be one workaround, although I actually do sometimes want multiline labels and to use \leq (just skipping the check for \l would be good enough. @kjellmf I'm happy to try to submit a PR if you would indicate what you think the best solution is. Of course, I can also just make this change in my local copy and be done with it.

I know you were asking for a new maintainer. I find this package very useful, I've unfortunately already adopted a lot of orphaned packages that are closer to my own research and I can't really take on another one.