MarkdownToNotebook: tableCell drops column dividers and width fitting for tables with a column count other than 2 or 3 on documentation templates

[mbahram]

Summary

tableCell (MarkdownToNotebook.wl, line 3743) keys the generic GridBox path entirely on $docTemplate === "Default":

GridBoxDividers -> {"Columns" -> {{$docTemplate === "Default"}}, "Rows" -> {{True}}},
GridBoxSpacings -> {"Columns" -> {{1.5}}, "Rows" -> {{0.8}}},
Sequence @@ If[$docTemplate === "Default",
    {GridBoxItemSize -> {"Columns" -> If[ncol >= 3, ...Scaled...], "Rows" -> {{Automatic}}}},
    {}]

A documentation-taxonomy template (any of $tableModTemplates: Symbol, Guide, TechNote, Overview, Chapter, BookChapter, ComputationalEssay, Essay, Format, ...) uses the *TableMod styles only for 2 and 3 column tables. A table with any other column count (4+, or 1) returns tableModStyleFor -> None and falls through to this generic path with $docTemplate != "Default". It therefore gets:

• no column dividers (Columns -> {{False}}), and
• no GridBoxItemSize at all (the Scaled column-width fit is Default-only).

tableItemSize[ncol] (line 3716) is still defined but no longer called.

HEAD behavior (486a861)

The non-resource branch gave these templates full column dividers AND tableItemSize[ncol] (Scaled widths so cells wrap and the table stays inside the page).

Effect

A wide (4+-column) table on a Symbol / Guide / TechNote / Chapter / Essay page loses its vertical rules and, more importantly, its width fitting: long-content columns are unconstrained and can overflow the page / deployed-cloud width. The width constraint was added precisely to prevent that overflow.

Repro

A Template: Symbol page with a 4-column table in ## Details:

Get[".../MarkdownToNotebook.wl"];
nb = MarkdownToNotebook["symbol-with-4col-details-table.md", "Evaluate" -> False];
Cases[nb, GridBox[rows_, opts___] /; ! FreeQ[rows, "Col3"] :> {opts}, Infinity]

Working tree:

GridBoxDividers -> {Columns -> {{False}}, Rows -> {{True}}}, GridBoxSpacings -> {...}
(* no GridBoxItemSize *)

HEAD (486a861):

GridBoxDividers -> {Columns -> {{True}}, Rows -> {{True}}},
GridBoxItemSize -> {Columns -> {Scaled[0.2], Scaled[0.233...], Scaled[0.233...], Scaled[0.233...]}}, GridBoxSpacings -> {...}

Which change introduced it

The uncommitted merge's tableCell resolution (the local Default / essay-table handling). The accompanying comment "other generic tables keep the historical row-only rule" is inaccurate: on HEAD these documentation templates got full frames plus Scaled widths, not row-only rules. The condition should distinguish resource templates (row-only, no widths) from Default AND the documentation templates (dividers plus width fit), rather than singling out Default.

Related but distinct

#92 (blank first row in Details tables) is a separate, row-level concern.

Severity

Low-medium: cosmetic loss of column dividers plus a functional loss of width fitting (possible horizontal overflow) for tables with a column count other than 2 or 3 on documentation templates. 2 and 3 column tables (the *TableMod path) are unaffected.