ebook fix: remove stray markup from the text

[jeremyschlatter]

Hello! Thanks for putting so much work into formatting HPMOR nicely. I'm re-reading it in ebook format in Apple Books right now and really enjoying it.

I noticed some stray markup in chapter 23:

"plus .5minus 1" clearly doesn't belong there. I looked into it and you can see the source of this markup in the original latex:

hpmor/chapters/hpmor-chapter-023.tex

Lines 125 to 140 in 9ecaeba

	And Harry brought out the original parchment with the hypotheses, and began scribbling.
	\vskip 1\baselineskip plus .5\textheight minus 1\baselineskip
	\savetrivseps
	\setlength{\topsep}{0pt}
	\setlength{\partopsep}{0pt}
	\begin{centering}
	\begin{samepage}
	\scshape Observation:
	\itshape Wizardry isn’t as powerful now as it was when Hogwarts was founded.
	\end{samepage}
	\vskip 1\baselineskip plus .5\textheight minus 1\baselineskip

The problem happens in step_3.py, which tries to remove this markup completely:

hpmor/scripts/ebook/step_3.py

Lines 53 to 54 in 9ecaeba

	# \vskip 1\baselineskip plus .5\textheight minus 1\baselineskip
	cont = re.sub(r"\\vskip .*?\\baselineskip", "", cont)

But because the regex uses a minimal quantifier instead of a greedy one, it only matches "\vskip 1\baselineskip", stopping at the first "\baselineskip" instead of the one at the end of the line. This leaves the errant bit of markup in the text:

plus .5\textheight minus 1\baselineskip

Which, because it does not start with a backslash, ends up inserted into the content.

The fix is simple: remove the '?', turning the ".*" into a greedy match instead of a minimal match. This matches to the end of the last "\baselineskip", completely removing this bit of markup from the text as intended.

---

Note: I only made this change because of the issue in chapter 23, but it also comes up in a few other places. Here's the full diff of tmp/hpmor-epub-3-flatten-mod.tex. I think these are all good changes, but I'm not sure. I'm not that familiar with the markup and I haven't figured out how to fully render the ebook yet to check how it looks:

# diff new/hpmor-epub-3-flatten-mod.tex old/hpmor-epub-3-flatten-mod.tex
164c164
< \newenvironment{writtenNote}{\fontspec[ExternalLocation]{Graphe_Alpha_alt.ttf}\scriptsize \renewcommand{\emph}{\uline}}\itshape }
---
> \newenvironment{writtenNote}{\fontspec[ExternalLocation]{Graphe_Alpha_alt.ttf}\scriptsize \renewcommand{\emph}{\uline} plus .1\baselineskip minus .1\baselineskip \begin{adjustwidth}{\parindent}{\parindent}\par\setlength{\parindent}{0pt}\setlength{\parskip}{\baselineskip}\itshape }
166c166
< \end{adjustwidth} }
---
> \end{adjustwidth} plus 1\baselineskip minus 1\baselineskip }
9255c9255
<
---
>  plus .5\textheight minus 1\baselineskip
9268c9268
<
---
>  plus .5\textheight minus 1\baselineskip
9287c9287
<
---
>  plus .5\textheight minus 1\baselineskip
9306c9306
<
---
>  plus .5\textheight minus 1\baselineskip
23525c23525
< \newcommand{\OmakeIVspecialsection}[2][1.5]{\vspace*{2\baselineskip plus 1\baselineskip minus 1\baselineskip}\noindent\hfill\scalebox{#1}{#2}\hfill\mbox{} \@afterindentfalse\@afterheading
---
> \newcommand{\OmakeIVspecialsection}[2][1.5]{\vspace*{2\baselineskip plus 1\baselineskip minus 1\baselineskip}\noindent\hfill\scalebox{#1}{#2}\hfill\mbox{} plus 1\baselineskip \@afterindentfalse\@afterheading

[entorb]

Dear @jeremyschlatter, thank you very much for the fix of yet another Ubuntu 24.04 update leftover! Looks great, will merge now.

PS: The easiest way to create the eBook is via Docker, see comments at the end of https://github.com/rrthomas/hpmor/blob/main/Dockerfile .