[DemchaAV]

Why

A layer's offset moves it on the page, and the DOCX export lost it without a word in two places.
Measured in Word 16 and LibreOffice on Windows, on a 400×600pt page with 72pt margins:

Where	Page	Before, in Word / LibreOffice	After, in Word / LibreOffice
a stack's one layer, position(text, 40, 10)	x 112	x 72 / 72	x 112 / 112
a band's layer, position(text, -20, 5)	x 52	x 72 / 72	x 52 / 52

After the change, a stack's one layer of three lines moved 40pt in stands at x 112 in both editors.
Its lines break at the page's words.

• A stack of one layer is written as its contents, in the flow, and its layer was written at the
  stack's left edge.
• A band holds each layer in to its box (holdIn), but only inward: a layer the page sets left of
  the stack was held at the stack's edge.

The one layer's offset down also moves it: the page sets the text 10pt lower than the stack starts.
The stack makes no room for it, so the page lays the text over what follows. Word's flow cannot
lay one line over another, and that loss was unsaid too.

What changed

• holdIn holds a block to its box on both sides. Where the page sets it past an edge, it
  stands out past it as far, by an indent below zero.

  • applyInset already writes a paragraph's indents below zero outside a table cell, and a
    table's w:tblInd too.
  • A layer moved whole runs as far past the other edge. It keeps the page's measure, so its lines
    break at the page's words.
  • Past an edge the block keeps its box's own width. The room to spare on the side its text does
    not lean on widened the three-line layer by 12.8pt, and it took two lines in both editors.
  • A table cell's text starts no further left than the cell's own. There a block stands left only
    as far as the indents round it give. The rest is named (layer offset), unless the block only
    draws. Its right side stays at the edge, as before: a line the page sets past it gets its room
    from the paragraph itself (letTheLineStandOut).

• writeContainerBody: a stack of one layer holds its layer through placeAcross, as it
  already holds an alignment's child. In a table cell the moved layer would run past the cell's
  right edge, so it is written where the stack starts.

• reportTheLayerMoved names the one layer, by more than half a point, in three cases:

  • set lower or higher than its stack starts;
  • in a table cell, set left or right of the stack's edge;
  • composed in a table's cell, where the stack has no place of its own in the layout, by its
    offset as given.

  It skips a layer that only draws. It also skips the vertical case where a band or a column sets
  the next block at the page's distance below what is above it, since that distance holds the
  offset.

• Docs:

  • the recipe: a bullet of its own for a stack of one layer, and the band bullet;
  • the capability matrix's layer-stack row;
  • the layers entries of DocxNodeFieldLedgerTest for the stack and the shape container;
  • CHANGELOG v2.5.0.

Verification

• Corpus, 62 DOCX before and after: all 62 are byte-identical, and the report's 1246 notes are
  identical.
  • A scan of the corpus's layers finds no stack of one layer with an offset, and no written layer
    set left of its stack.
  • The one negative offset, in invoice-payments, belongs to the masthead's accent bar, which is
    drawn.
• Example: word-export-companion.docx was regenerated. It differs from the committed one only
  in docProps/core.xml, the export's time.
• DocxLayerOffsetTest (new, 14 tests):
  • one layer moved across, both indents and no note;
  • moved down, named;
  • moved up, named;
  • set in by its margin and the stack's padding, not named;
  • one that only draws, in the flow and in a band, not named;
  • one a band writes first, set down by the band, not named;
  • a band's layer left of the stack written 20pt out, while a layer inside is held in and a
    right-aligned one at the edge is not pushed past it;
  • in a row's cell: written at the edge and named; 12pt of 20 given by the indents round it and
    the rest named; 24pt round it and not named; a drawing not named; one layer moved across,
    written at the stack's edge and named;
  • in a table's composed cell, named by its offset.
• 16 sabotages. 15 are caught. The 16th moves the past-the-edge threshold from −0.5 to +0.5pt,
  which changes an indent by less than half a point.
• ./mvnw -B -ntp clean verify: BUILD SUCCESS (core 821, render-docx 1819, examples 93, qa 1820).
  The knowledge pack's --check passes.

Lane: render-docx (semantic backend). DOCX output changes only where a layer's box stands past
its stack's edge, or a stack's one layer is moved across. The report gains notes only where an
offset is not written.