alehelandClaude Opus 5.5 e71a946c0f fix(edit): a backdrop is only a fill the graphics state paints plain white ...

Review of #2815 (FredApps): two ways the detector took real content for a
page's own white backdrop and replaced it by default.

- A `gs` sets only the keys its dictionary has, but each one replaced the
  whole opacity decision and read every key it left out as its default,
  so `/Transparent gs /LineOnly gs 1 g ... re f` (ca 0.5, then only a
  line width) counted as opaque. Fill alpha, soft mask and blend mode are
  now kept one by one, through `gs` and `q`/`Q`.
- A transfer function was never read: TR or TR2 mapping 1 to 0 paints
  `1 g` black, and the fill was still replaced. The transfer function is
  tracked too, TR2 over TR in the same dictionary, and only /Identity
  (and /Default for TR2) counts; anything else leaves the fill alone.

Tests: nine graphics states that must keep the fill (each also checks Add
Background leaves the content as it was) and nine that still find the
backdrop (keys set back, TR2 /Default over a TR function, q/Q restoring),
plus an end-to-end render of the reviewer's translucent case under a red
background. All the keep cases fail on the code before this change.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

2026-10-25 08:31:05 +01:00

..

src

fix(edit): a backdrop is only a fill the graphics state paints plain white

2026-10-25 08:31:05 +01:00

Cargo.toml

fix(edit): backdrop copies keep no reference that outlives a redaction

2026-10-23 23:58:42 +02:00