The archive limits bound what one import extracts (256 MiB an entry, 1 GiB in
total), and one pixel layer is skipped past 64 megapixels, but nothing bounded
what the layers materialized out of that cost: each bitmap's declared
`BmpW`/`BmpH` sizes its RGBA output and its decode planes, with or without tile
data, so a small document with many layers could still allocate without end.
`Limits` gains `max_pixel_bytes` (1 GiB by default, the budget the other
importers allow decoded pixels). `Reader` admits a layer before `decode`
allocates it: the layer's RGBA joins the layers already materialized, and its
working planes are counted with them, since every earlier layer is still live
while this one decodes. Past the budget the import fails with `Error::Limit`,
which `photocraft-io` reports and falls back from to the embedded preview.
Tests: a synthetic 300-byte document declaring layers with no tiles at all - one
layer inside the budget imports, the second past it is rejected before
allocation, and a declared 2048x2048 layer is rejected under a 1 MiB budget.
The fuzz targets get a small pixel budget so mutations reach the new rejection
path.
Co-authored-by: DeepSeek <noreply@deepseek.com>
photocraft-affinity now reads native Affinity documents (container
versions 8-12): the FAT and revision chain, stored/zlib/zstd entries
with predictors and CRC checks, the tagged object stream in doc.dat,
and the document model (pages, artboards, layers, groups, curves,
geometric and compound shapes, fills, gradients, strokes, text, placed
images, pixel layers, masks and embedded-document caches). Every size
is bounded and malformed input returns an error.
photocraft-io maps it to an RGB8 document with artboards, groups, shape
layers, type layers, embedded smart objects, pixel layers and
vector/layer masks; what can't be mapped is listed in the warnings. The
embedded preview is now only a fallback when the native data can't be
read, and only that preview is refused by Place and warningless imports.
`cargo xtask corpus --affinity` pins 21 public CC0/MIT documents,
sha256-verified; the io corpus test compares each import with the
thumbnail Affinity saved in it (mean difference 0-4.6 of 255).
Affinity export is not implemented: no Affinity installation was
available to validate written files.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01GQPh8UDgMyARR5Hat9UchC
Read the indexed version-12 PNG preview with bounds, chunk ordering and CRC checks. Show native-content and resolution warnings, preserve the source through normal and automation opening, and reject auxiliary routes that cannot display the warning. Add format documentation, malformed-input and save-lifecycle tests, native-oracle hooks and parser/import fuzz targets. Editable native layers and Affinity export remain unsupported.
