Dollar sign destroys escaping

[schra]

Tested sphinx-math-dollar versions: 1.2 and c60310d

Exemplary reST code:

Test
----

#. **t**\ est
#. **t**\ est :math:`x`
#. **t**\ est $x$

If you didn't know, **t**\ est sets the first character in bold. In reST you can't just write **t**est like in Markdown.

Rendered output:

[asmeurer]

If I had to guess, there is some issue with this nasty regular expression

sphinx-math-dollar/sphinx_math_dollar/math_dollar.py

Line 52 in c60310d

dollars = re.compile(r"(?<!\$)(?<!\\)\$(\$)?([^\$ ](?:(?<=\\)\$|[^\$])*?)(?<!\\)\$(?(1)\$|)")

[schra]

Hm, doesn't seem to be the case because if I add the following line to the tests, it works just fine:

assert split_dollars(r"#. **t**\ est $X$") == [("text", r"#. **t**\ est "), ("math", "X")]

The problem is in extension.py. If I replace

        data = split_dollars(str(node).replace('\x00', '\\'))

with

        data = split_dollars(str(node))

then the bug vanishes - however then some math stuff is also rendered weirdly.

I think the problem is that for some reason the \ from the reST is turned into a \0 when we receive the reST in the extension and when we then replace all \0 with a \, we turn the \ into a literal \ and not an escaping sequence.

[asmeurer]

This has to do with the change from #22 (#24).