A fresh Layout1 is already ISO A3 landscape (ezdxf R2018 default: 420 x 297,
plot_rotation 0), so an A3-only /MediaBox read-back passed with
page_setup_apply stubbed to a no-op: the A/B gate row and the v4 matrix task
could not fail on the setter. Both now apply ANSI B (432 x 279, a size no
fresh document has; spec section 9 names it) and read that PDF first, then
apply ISO A3, read its PDF, and require the setter's changed.size_mm to have
moved from B to A3. The stub fails at the first PDF.
The moved-sheet comparison is +/-0.5 mm, the spec's tolerance, not exact:
measured live on AutoCAD 2026 (scratch Documents.Add(), closed unsaved), the
COM engine reports ANSI B as 431.8 x 279.4 and the DWG To PDF.pc3 file's
MediaBox as 431.8 x 279.4 then 420.158 x 297.039 for A3; the task passes
there with changed.size_mm [[431.8, 279.4], [420.0, 297.0]]. Headless it is
[[432.0, 279.0], [420.0, 297.0]].
tests/test_benchmark_v4.py gains the mutation test the finding describes
(setter stubbed -> both rows must fail; both passed on the old code) and a
run of the gate row itself; the headless task test asserts the B stage.
README rows and the tasks_v4 docstring say what the task now does; the README
collected-tests figure follows the two new tests (3282 -> 3284). The
regenerated A/B report against v1.5.1 is byte-identical (26 -> 32/32).
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01FKFStjEFzpGyLq5bMpWxTd
tasks_v4.py extends v3 with one task the reader can fail on its own: the
example spec is drawn through pid_from_spec's code and read back by the
graph builder, which never sees the spec. The runner, the chart and the
doc-number gate now default to v4; --matrix v3 / v2 reproduce the earlier
sets, and tests/test_benchmark_v3.py labels its full-matrix run "v3"
explicitly now that the default has moved.
The plan's adapter check expected the two unnumbered lines to come back
with no line number; draw_line builds one from the default number_format
(bare sequence when size/service/spec/insulation are empty), so the task
asserts the two authored numbers on the two process lines and sequence-
built XDATA numbers on the other two instead.
The published A/B report still covers 26 checks; Task 21 re-runs it
against v1.5.1, which is what clears the remaining doc-number drift.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01FKFStjEFzpGyLq5bMpWxTd
