A project file, an .aep, a timeline document or a Lottie file could give a
layer a time stretch of 1e-300 %, 0 or 1e300 %. Layer and comp time divide
by it and the audio mix read about usize::MAX source samples for one block,
which overflowed or tried a huge allocation and aborted the app.
- limits::stretch brings a stretch within After Effects' range (±1 % to
±9900 %, Layer.stretch in the scripting guide), sign kept; 0 and NaN are
100 %. Opening a project file corrects each layer and says so; a stretch
written as null (NaN in an auto-save) now opens instead of failing.
- .aep import and Lottie import clamp and report the stretch; timeline
import clamps the clip speed and warns.
- layer.timeStretch refuses a non-number and more than 9900 %; the Time
Stretch dialog's ranges match.
- Layer::layer_time / comp_time and the audio mix use the clamped stretch,
so a value set in memory can't divide by zero or read without bound.
Fixes#3247
Problem: comp.new/comp.settings clamp sizes to 30,000 px, frame rates to
0.001-1000 fps and motion-blur samples to 2-64, but reading a project
(.ecproj and .ecprojx, templates, recovery, offload) accepted any value:
a 4-billion-px comp, solid or footage frame, a 0 or 10^18 fps rate
(zero-length frames), a negative duration or 4 billion blur samples all
reached the renderer. New Solid, Layer Settings, Import Solid/Placeholder,
Crop Comp and PSD import set sizes without the upper bound, and comp
sizes past 2^32 wrapped.
Fix: one set of limits in effectcraft_project::limits. Project::from_json
brings every item (and proxy) within them; from_json_repaired also says
what it changed, which file.open returns as `repaired` and shows in a
toast, so the project still opens. Project::add_item applies the same
limits to every new item, and the size-setting commands clamp with the
shared helpers.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
vangel76
