TOC section-number column too narrow — multi-digit section numbers collide with titles

[asluk]

Summary

In the generated PDF table of contents, section numbers of two or more digits run into the section title with no separating space. With wider numbers (e.g. 10.10) the number visibly overlaps the start of the title.

Affected

Any spec built with doc_build that has ≥10 top-level sections. Observed in both the Geometry spec (severe) and the Core spec (mild), so it is not spec-specific.

Evidence

• Geometry spec (22 sections): 10Cube, 10.1Overview, and especially 10.10Example show the number jammed against — or overlapping — the title, while single-digit entries (9 Gprim, 9.1 Overview) are spaced correctly.
• Core spec (16 sections): 10Composition, 10.1Scope, 10.2Overview show the same gluing. It reads as merely "tight" rather than overlapping only because its subsection numbers never exceed 10.8-width; a XX.YY entry would overflow the same box and overlap.

(TOC screenshots from both specs can be attached.)

Root cause

template/after-header-includes.latex customizes the deepest TOC level (\l@subsubparagraph) and raises secnumdepth/tocdepth to 6, but never widens the number columns for \l@section / \l@subsection / \l@subsubsection. The document uses the default article class, whose \numberline boxes for those levels are sized for single-digit numbers, so any number ≥ 10 (and any X.YY subsection) overflows its box and collides with the title.

Not a font issue — it reproduces with the bundled DejaVu fonts on Linux.

Suggested fix (direction, not yet validated)

Widen the TOC number columns in after-header-includes.latex, e.g. with tocloft:

\usepackage{tocloft}
\setlength{\cftsecnumwidth}{2.6em}
\setlength{\cftsubsecnumwidth}{3.4em}
\setlength{\cftsubsubsecnumwidth}{4.3em}

or by redefining the \@dottedtocline number widths directly. Either should be validated against a spec that reaches XX.YY numbering (the Geometry spec is a good test case), and checked for interaction with the existing titlesec setup and the custom \l@subsubparagraph definition.

Fixing this upstream corrects the Core and Geometry specs (and any future spec with ≥10 sections) at once.

[OleksiyPuzikov]

@asluk This is fixed in #99 - note however that instead of proposed hardcoded expansion of the chapter number column (that kept the alignment of chapter titles for the TOC) I went with the dynamic number sizing in order to fix any possible number sizing - and now the chapter titles are not aligned. I'm not sure how this looks for you, so please review the attached example PDF and comment.

[OleksiyPuzikov]

aousd_aousd_doc_build.pdf

[asluk]

@OleksiyPuzikov Verified PR #99 against the Geometry spec — the severe case you couldn't test (22 top-level sections, and a subsection that reaches 10.10). Built the full PDF with doc_build pinned to your branch head and rendered the TOC.

The collision is fully resolved, including the worst entry. Here is TOC section 10 (which reaches 10.10):

Before (current pinned rev) — numbers glued to titles, 10.10Example overlapping:

After (#99) — clean spacing on every entry:

Single-digit, double-digit section, and the XX.YY subsection all render correctly now.

On the alignment tradeoff you flagged: confirmed it's there — because each \numberline sizes to its own width, 10.10's title starts a hair right of the 10.1–10.9 titles, and double-digit top-level entries nudge their titles right of single-digit ones. It reads as a very slightly ragged title left-edge. I'm happy to keep the dynamic sizing as-is — it's standard auto-numbering behavior and a non-issue next to the overlap it fixes. (If we ever wanted strict alignment back, a max(natural-width, per-level-min) on the box would do it, but I don't think it's worth the complexity.)

Good to merge from the Geometry side. Thanks for turning this around — once it lands I'll bump our pinned rev and re-run CI.